?Startup Issues - WTF?

[Kooldino]

Ok, so out of nowhere I started getting some startup issues.

It happens on occasion, at what seems to be complete random.

As soon as I turn the key into the "on" position, I hear a "pop", something like how a vac line sounds when it pops off.

Then I go to turn the key, and the car won't start.

After trying several times, the car will start, but it will die instantly. However, if I hold the throttle, all is well. A:F ratio is stoich. But the moment I let it go, it will die again.

If I turn it over, keep my foot on the throttle for a few minutes, and let it warm up, it will eventually behave like normal and drive fine.

I've checked all of the vaccum lines, and it all seems fine. I'm at a total loss right now.

I plan on checking my spark wires tonight, and beyond that, if it happens again, I'll check the connections on my MPI.

Any other suggestions?

[Kooldino]

Came up with a possible idea...PCV valve? Seems like I've been getting a lot of blowby through my crank case vent on the side...maybe the PCV isn't working correctly?

[hazeXban]

Could be a thing to check out, a lot of blow by isn't normal. At least I don't think it is.

[hazeXban]

Good luck with the problem, let us know!

[peepsalot]

If it's PCV, supposedly you just shake it to tell if it's good. rattling PCV = good

[Kooldino]

If it's PCV, supposedly you just shake it to tell if it's good. rattling PCV = good
That's what I hear. I'll have to shake dat ass before I leave work.

[BradC]

Would a PCV valve cause a running issue though? What would explain the pop then? The PCV valve doesn't "do anything" when the key is flipped...

[Kooldino]

Would a PCV valve cause a running issue though? What would explain the pop then? The PCV valve doesn't "do anything" when the key is flipped...
This is true. I just thought I'd check it out due to the blow by I've been getting.

The pop totally baffles me. It's not super loud though. just sounds like pressure being released.

[BradC]

Any funny smells? Gas? Can you hear the fuel pump pressurize?

Maybe a pop like a spark arcing as soon as power is distributed?

[Kooldino]

Any funny smells? Gas?
Nope.


Can you hear the fuel pump pressurize?

I can hear it turn on.


Maybe a pop like a spark arcing as soon as power is distributed?

I don't think it's that. It's more of an air pressure kind of pop.

[Kooldino]

Ok, so after inspecting the area around my throttle body, I came to the conclusion that something looked like it was missing. I assume it was just a bolt, so I threw one in there. Anyone wanna double check for me? Maybe this was a contributing factor? Either way, it's good to have the bolt back in there. :)

[peepsalot]

well did it fix your problem?

[Kooldino]

well did it fix your problem?
Well, it only happens at random, so I dunno. I got like 5 good starts after the clusterfuck today, and that was before i replaced the bolt.

[Lil Freek]

seriously sounds like your PCV valve.
i forgot to put mine back in after working on the car the other day and it had the EXACT same symptoms as yours.
i have the Millenia PCV valve now.. dunno if that makes a diff or anything in performance, but it sounds like your PCV valve is faulty or something.

[BradC]

Keep us posted on how it works out.

[Kooldino]

seriously sounds like your PCV valve.
i forgot to put mine back in after working on the car the other day and it had the EXACT same symptoms as yours.
i have the Millenia PCV valve now.. dunno if that makes a diff or anything in performance, but it sounds like your PCV valve is faulty or something.

I took that out yesterday and jiggled it around. Seemed fine. I too, have the Millenia valve.

Anyway, it fired up the second I breated on the key this morning. So I guess we'll see.

[BradC]

How often did it make the "pop" noise? If once, maybe that "pop" was that bolt saying c-ya...

[Kooldino]

How often did it make the "pop" noise? If once, maybe that "pop" was that bolt saying c-ya...
It could have been, but doubtful. Apparently the VICS opens when you turn the key to "on", so maybe it flipped and leaked air out of that spot in the IM?

[Kooldino]

Update: So far, so good...

[Kooldino]

Ok...so today during lunch, I went out.

Put the key in, turned it to the on position...heard the quiet "pop"...oh crap.

Tried to turn it over, and it didn't want to start. I stayed on it for 6 or so seconds and it fired up...and then immediately died.

I popped the hood, opened and closed the VICS actuator (didn't seem abnormal).

Got back in the car, and it fired right up. WTF?

[BradC]

Goddamn Gremlins man, they'll getcha every time!

Any funny smells or any other symptom other than the "pop"?

Did you try the PVC like someone mentioned? You said it rattled like all is good though, right?

[Kooldino]

PVC was fine.

Also, on Friday, I heard the pop again when I turned the key (but BEFORE i went to turn it over).

I popped the hood to inspect...opened and closed the throttle and the VICS. Nothing weird.

Waited 3 mins...put the key in...and it fired right up.

Whiskey
Tango
Foxtrot

So I'm guessing that if I hear the pop and don't try to start it right away, everything will be fine??? I'm SO confused.

[Mr. Win]

i say fuel pump relay or something.

[peepsalot]

Your car is haunted. Have you killed anyone in it recently?

[BradC]

i say fuel pump relay or something.
Had a smiliar problem on my friends 'teggy, tracked it to the main relay (on a honda they have a relay w/3 relays in it, FP, ECU, and something else...).

Carry some leads with you and when the pop happens, pull the relay and apply power, see if it energizes. Does the pump come one when you turn the key?

[Kooldino]

Your car is haunted. Have you killed anyone in it recently?
NO.

Out, damned spot!

[Kooldino]

Carry some leads with you

Some leads? what do you mean?


and when the pop happens, pull the relay and apply power, see if it energizes.

Can you explain this a little better? Not sure what you mean.


Does the pump come one when you turn the key?

It should in theory...don't know if it actually does or not.

[BradC]

Dana,

By leads I meant test leads.

Get some wire and solder alligator clips on the end or buy premade ones (2).

Take the relay out and put power to it (12v) with the cords, read the schematic printed on the relay...it will show you Vcc and ground.
If the relay is good, when power is applied it will energize. You will hear and feel it click in your hand. If it doesn't respond, its f'ed.

Have someone stick their head around the tank and flip the key after she has been sitting. Make sure it pressurizes, it will make a nice bzzzz.

If you have questions about the relay thing I can try to explain better.

[Kooldino]

Ok, so I'm just testing the relay OUT of the car then. That should be doable.

[BradC]

Ok, so I'm just testing the relay OUT of the car then. That should be doable.
Yuppers!

I was suggesting carrying the stuff with you so you can do it the second she doesn't start.

[Kooldino]

Gotcha. Will do. IIRC, it's a pink 40A fuse/relaym, and it's about 3/8" squared.

[Kooldino]

Well, I swapped the relay with another one, and it didn't do jack.

I still get that loud POP noise when the key turns on before I start it.

Also, FWIW, before I put a springy hose clamp on it, the vac line from my intake mani to my stock MAP sensor would blow off a lot.

[Mr. Win]

starter...

[Kooldino]

But the car STARTS. It's just that it sometimes bugs out and wants to stall after it is started.

Unless for some reason the starter is putting such a load on the motor at idle that it's gheying it up.

[Kooldino]

So about every time I go to start my car, I first have a friend turn the key into the "on" position as I look under the hood to see if it makes the "pop" noise.

Finally, after doing it all week, I finally caught one of said "pops". It sounded like the kind of pop you hear when you blow up a brown paper bag, and smack it really hard.

Anyway, my head was over the center of the engine bay, and the pop sounded like it came from the driver's side...near where my air filter and my MBC are. But I can't be sure.

Right after the pop, I heard a "psssssssshh" from what sounded like the belt area.

It all happened so fast, it was hard to tell.

Anyone know what turns on when you turn the key to the "on" position, but doesn't turn on when you turn the ACC on?

[Mr. Win]

hmm...

[peepsalot]

You should get on cartalk.

[Marik123]

Could it be the fuel pump? On older cars, when u turn key to ON position, you should able to hear some noise coming from the fuel pump...

[BradC]

So about every time I go to start my car, I first have a friend turn the key into the "on" position as I look under the hood to see if it makes the "pop" noise.

Finally, after doing it all week, I finally caught one of said "pops". It sounded like the kind of pop you hear when you blow up a brown paper bag, and smack it really hard.

Anyway, my head was over the center of the engine bay, and the pop sounded like it came from the driver's side...near where my air filter and my MBC are. But I can't be sure.

Right after the pop, I heard a "psssssssshh" from what sounded like the belt area.

It all happened so fast, it was hard to tell.

Anyone know what turns on when you turn the key to the "on" position, but doesn't turn on when you turn the ACC on?

I assume you checked all vac lines, etc, all the dumb little shit that will piss you off when you find it 3 weeks later?

[Kooldino]

You should get on cartalk.
What's the phone #?

[Kooldino]

Could it be the fuel pump? On older cars, when u turn key to ON position, you should able to hear some noise coming from the fuel pump...

It could be, but why would it make a "pop" noise?

[Kooldino]

I assume you checked all vac lines, etc, all the dumb little shit that will piss you off when you find it 3 weeks later?
Yessir, except for that one vac line that's under the intake runners.

[peepsalot]

http://www.cartalk.com/

Wanna ask Click and Clack a question on the air?
Call 1-888-CAR-TALK (888-227-8255)

[peepsalot]

You said you checked the operation of the VICS, what about VTCS, maybe it is sticky and pops into place, or the actuator diaphragm is making a popping sound somehow?

[Kooldino]

I have no VTCS.

Also, I came up with a theory.

I'm not sure how exactly the EGR functions, but bear with me.

The tube that comes out of my EGR is crimped and welded shut. I wasn't sure if it was possible for my EGR to be open while I was in boost, and somehow that tube fills up with air pressure. Then, when I turn it to the "on" position, the EGR valve opens and creates the "pop" noise?

Or is this totally impossible?

[BradC]

I have no VTCS.

Also, I came up with a theory.

I'm not sure how exactly the EGR functions, but bear with me.

The tube that comes out of my EGR is crimped and welded shut. I wasn't sure if it was possible for my EGR to be open while I was in boost, and somehow that tube fills up with air pressure. Then, when I turn it to the "on" position, the EGR valve opens and creates the "pop" noise?

Or is this totally impossible?
EGR only recircs under light throttle/cruising conditions. Instead of having it crimped up, why don't you cut a block off plate for it? If for no other reason it would make for a prettier install.

[Kooldino]

Ok...

It's not the MPI...I pulled that, and it made no difference.

Also, while the MPI was plugged in, it was reporting a CONSTANT A:F ratio from the primary O2 sensor. It didn't do it's little sin wave thing like it normally does. It just drew a flat line.

Also, when I unplugged the primary O2, it ran about the same.

I checked the wiring in my FM clamp...seemed ok.

I pulled the plugs...they looked fine...a little browned.

Ran a compression test...that was fine.

[Kooldino]

Ok, the "pop" happened again and I got to see it again (while my friend turned the car to the "on" position). On the driver's side of the engine bay lies my intake and my joePMBC.

Both of them "jumped" when the pop sound was made. This confused me. Then I heard a "fizz" come from the passenger side of the engine bay.

My friend came up with this theory:

-my extra fuel rail in the intake mani may have a slightl slow leak. Maybe the rings aren't 100%, or mayble the injectors or bad. Something along those lines.

-When you turn the key to the "ON" position, the MPI tuner sends SOME KIND of signal to the ignition coils. Whether or not it fires the plug we don't know. But assuming it does...

-it would then ignite the few drips of fuel and send the pressure through whatever opened valves there may be, through the intake and exhaust manifolds.

That would explain the "pop" noise. Although it doesn't totally explain why the car would run funny afterwards if I tried to start it without it sitting. Maybe the pressure would create a bubble in the fuel line somewhere through the less-than-perfectly sealed injector?

So anyway, to test this theory, before I start the car each time for the next week, I will...

1-unplug the two wires that plug into the ignition coils.
2-Turn the key to the "on" position
3-plug the wires onto the ignition coils one at a time.

If the "pop" happens while I do #3, then my friend just may be correct. Thoughts?

[SpicyMchaggis]

that seems like a pretty rational explanation. I'd say try that then take it back to the drawing board if it doesn't work..I'll think about it for a little bit.

[Brian MP5T]

Air Filter.

[Kooldino]

Air Filter.
Why/how could this be the air filter?

[BradC]

Did you try to troubleshoot that FM clamp yet Dana? How is the car idling now?

[Brian MP5T]

Why/how could this be the air filter?

My Car ran like ass, I Thought it was a major problem, It was the F-Ing AF...

(cabpatch)

[Kooldino]

Did you try to troubleshoot that FM clamp yet Dana? How is the car idling now?
Good. I turned up the idle screw that day, and the sine wave returned to normal. Idling around 900 now. <3

[BradC]

Good. I turned up the idle screw that day, and the sine wave returned to normal. Idling around 900 now. <3
hmm...I wonder why the o2 wasn't oscillating at your 750 idle? Still get that pop though? I wish we could have heard it that day. I keep imagining a pop like blowing the top off of a pringles can or something, but after reading your friends theory I am imagining a pop like a backfire or similar.

[Kooldino]

hmm...I wonder why the o2 wasn't oscillating at your 750 idle?

My idea is that mabye there wasn't enough exhaust gas for the sensor to do it's thing (esp with the turbo before it)..



Still get that pop though?

Yup. Just got it yesterday before leaving work.



I wish we could have heard it that day. I keep imagining a pop like blowing the top off of a pringles can or something, but after reading your friends theory I am imagining a pop like a backfire or similar.

It kind of sounds like a Pringle's pop though. But Loud. Like you popped a brown paper bag full of air.

[wicked]

I had a issue like this,it was cuased by my MBC,not sure how,but I could disconect it,and reset the ECU,and everything was fine.
however,if I put the boost controler back in,"POP",and it ran like ass.

[BradC]

I had a issue like this,it was cuased by my MBC,not sure how,but I could disconect it,and reset the ECU,and everything was fine.
however,if I put the boost controler back in,"POP",and it ran like ass.
Did it ever come back, or do you run an EBC now?

[Kooldino]

I had a issue like this,it was cuased by my MBC,not sure how,but I could disconect it,and reset the ECU,and everything was fine.
however,if I put the boost controler back in,"POP",and it ran like ass.
NO effing way. Was it a loud pop? Was it intermittent? Did it happen on Key on? Did you have a JoeP MBC?

[wicked]

It was a definatly a noticable "POP",and instantly I had drivability problems.at first it was itermitant,but not for long,after about a month it did it every time I tried to put the boost controller in.I was useing a turbo XS,the reg. one,but switched to the highperformance one,and it still happened.

the odd thing is I was still reading full boost,and NONE of my sensors seemed out of range when I put it on a scan tool.

so,try removing your boost controler,and reset the ECU.see if it helps

[Kooldino]

Just a question...did your problem happen on key on, before you turned it over?

[Scotty878]

Weird...subscribing...hope you can get it fixed!

[wicked]

no,only running,once when turning it over.

[Kooldino]

no,only running,once when turning it over.
Different problem then. Mine is on "key on" before I even attempt to turn it over.

[Kooldino]

Ok, so back to this problem. I came out of the diner the other night, the car was sitting for 45 mins or so.

I turn the key into the ON position...and POP.

When I turned the car over, it started running off the charts rich at idle (richer than 10:1).

I let it warm up, no dice.

I started to drive around, and my A:F ratio was all over hte place. 10:1, 18:1, anything but stoich.

So I check my ECU, and it's giving me weird MAF codes. I shut the car down, pop the hood, and switch to my alternate MAF (the MAF I normally run is on the boosted side, but I also still have the MAF behind the air filter bolted on just in case). I fired the car up and everything was perfect. Drove an hour home.

I'm guessing that "POP" made some kind of backfire through my intake (like my friend theorized before...see page 4 of this thread) and fried my MAF.

Tonight, I finally got around to pulling the "bad" MAF out, only to discover that it's completely missing the thin MAF wire that it uses to determine the A:F ratio. I don't know where the hell it went. It could have run through the motor (damaging things in the process), or it could still be sitting in my IC/IC pipes somewhere. FABULOUS.

Tomorrow night I'm going to pull the plugs and do a comp check to check for signs of damage.

[BradC]

Wow Dana, that blows. What ever came of the o2 sensor issue? Are you still going to run the boosted MAF? What do you think caused the motor to sneeze through the intake?

[Kooldino]

Wow Dana, that blows. What ever came of the o2 sensor issue?

Everything was fine with that once I turned the idle screw up.


Are you still going to run the boosted MAF?

Yes, only because I think I know what caused it to happen.


What do you think caused the motor to sneeze through the intake?

http://www.msprotege.com/forum/showpost.php?p=1883289&postcount=48

Also, every time I ran his test, it never happened. Between that fact and what happened the other night, I think he's right.

[doctormike]

where is the idle screw? I assume it can raise the idle by adjusting the air fuel mixture.......i have a protege 5...2.0 motor....

[Kooldino]

Ok, so in the past two weekends, I've replaced 7 of my 8 injectors in hopes to rule out my "leaky injector" theory (I couldn't replace all 8 since I didn't have 8 new ones).

The other day, after I replaced said injectors, I turned the key on. Instead of the normal "pop" sound on key-on, it was a little more of a "whoosh" sound...like fluid was being sprayed.

Just to check, I pulled spark plugs 3 and 4. BOTH of them were wet with fuel. THIS explains some things...

When it did make the "pop" sound:
-It was hard to start (since the plug was soaked w/ fuel)
-It would run crappy and stall (same reason)
-After holding the revs at 3K for a couple of minutes, all would be well again (since it would finally burn off said fuel)

I put everything back together and went to turn it over. It took a good 10 seconds to start, and then according to my WBO2, I was running rich (11:1 or so).

Eventually it made it's way back to stoich.

So, SOMETIMES on key on, it seems like fuel is being sprayed into the cylinder somehow...

[Kooldino]

bump

[BradC]

Can you disconnect the extra injectors and rule out the MPI making them fire prematurely?

Does the MPI change any values of your stock injectors, or only controls the added injectors?

[Kooldino]

Can you disconnect the extra injectors and rule out the MPI making them fire prematurely?

Yeah, I planned on just pulling the plugs off of them for that reason.

Just for grins, I watched what my MPI does during startup, and it apparently does not turn the injectors on. But I'll still disconnect them to see.


Does the MPI change any values of your stock injectors, or only controls the added injectors?

Just the extra injectors.

[BradC]

Just for grins, I watched what my MPI does during startup, and it apparently does not turn the injectors on. But I'll still disconnect them to see.


Even though its not reporting a signal to them, maybe it is malfunctioning somehow and not displaying that??

I doubt the stock ECU is telling the stock injectors to douse your plugs at startup, there has to be something though...

[Kooldino]

Even though its not reporting a signal to them, maybe it is malfunctioning somehow and not displaying that??

I doubt the stock ECU is telling the stock injectors to douse your plugs at startup, there has to be something though...
I totally agree.

[Kooldino]

Ok, so here's what I did THIS weekend:

I made a power switch to turn the MPI on and off. It also works as a kill switch, since the MPI sits between the ECU and the ignition coils.

So now, i can have the MPI switched OFF and turn the key ON. No "pop" noise. Then, I'll flip the switch, turning the MPI ON. Pop goes the weasel.

[BradC]

Ok, so here's what I did THIS weekend:

I made a power switch to turn the MPI on and off. It also works as a kill switch, since the MPI sits between the ECU and the ignition coils.

So now, i can have the MPI switched OFF and turn the key ON. No "pop" noise. Then, I'll flip the switch, turning the MPI ON. Pop goes the weasel.
Did you do the unplug the injectors thing? Where you at Zoom-zoom live, it was (first) !

[Kooldino]

No ZZL for me.

I didn't try the injector unplug thing, only because it's a pain to do evey time (it would take about 3 mins to pull every time i wanted to do it...the plugs are hard to get to).

[Mr. Win]

So if im reading this right... MPI = T3h l053?
Ok, so here's what I did THIS weekend:

I made a power switch to turn the MPI on and off. It also works as a kill switch, since the MPI sits between the ECU and the ignition coils.

So now, i can have the MPI switched OFF and turn the key ON. No "pop" noise. Then, I'll flip the switch, turning the MPI ON. Pop goes the weasel.

[Kooldino]

Ok, so here's what I do every time I start my car.

The switch I ran to power on/off the MPI Tuner is set to OFF.

I turn the key into the ON position.

I switch the MPI switch to ON and watch the boost gauge.

If I don't hear the "pop", I turn the car over.

If I DO hear the "pop", I'll usually notice that the boost gauge jumps to about 20psi for a second. Odd...especially since the motor isn't running. It's like something is holding that pressure and releasing it when I hit that switch. Either that, or something is CREATING that pressure when I turn that switch...

[Kooldino]

Man, no love?

[miltont]

Still having the problem?


Man, no love?

[Kooldino]

Yeah. :(

[miltont]

Im having weird idle problems, yesterday i was @ the dyno and my car was @ idle and suddenly we heard your pop sound, we noticed in the back side where fuel pressure regulator is, a thing that is similar to a (Wastegate) where the secondary runners are, activating. That should not be activating itself.
Im looking for more info on this type of problem.



Yeah. :(

[Kooldino]

Im having weird idle problems, yesterday i was @ the dyno and my car was @ idle and suddenly we heard your pop sound, we noticed in the back side where fuel pressure regulator is, a thing that is similar to a (Wastegate) where the secondary runners are, activating. That should not be activating itself.
Im looking for more info on this type of problem.

At idle though? My car does it on Key ON, before the car is running.

Can you post a pic and circle the thing that's activating?

To me, it sounds like VTCS (internal WG looking thing on the passenger side), and that SHOULD activate itself.

[Metal MP5]

cant remember how i got to this thread but just wanted to know if you ever figured it out?

[Metal MP5]

OMG memory sucks lol ... i got here from a link you posted in Linux' thread lol

[green dart]

i assume the mpi is a controller that controls the extra injectors, maybe you mpi is malfunctioning and when the engine is shut off the extra injector sprays some fuel into the cylinder just before or just after the engine stops turning, when you go to turn it on the ecu energizes the spark plugs and ignites any fuel in the cylinder and if the valves are open will backfire into the intake thats where you get pressure on the boos guage. try to turn the mpi off just before you shut off the engine and see if it happens again.
If thats not it maybe it sprays fuel just as you turn the key to the on position .

[Kooldino]

This same problem occurs with the haltech EMS on other cars.

[StealthWyvern]

Did you ever get this problem solved?

[Kooldino]

Nope

[PGFracing]

Have you solved this problem yet. My car is doing the exact same thing. It went bad the same time the transmission blew a seal and went bad. I put new plugs in that helped a little but it still won't idle right and have to give it gas to run right. Have you come up with any solutions yet? To me it sounds like it's igniting to early, like the timing is off on just that one cylinder. The one closest to the oil cap.

[PGFracing]

I put in a pretty much new EGR valve and the problem went totally away. It wouldn't even idle before, now runs perfect. I suspect you have the same problem. Sounds just like mine.

[Kooldino]

Hmm, I don't think we have the same issue. Could you describe yours in detail?

[nvmsp]

Hey, my car does that pop shit too. Just started not to long ago and I have no idea what it is.

[nvmsp]

I was thinking maybe it's the exhaust, a nice little backfire to start the day. ?


Or already took off the heatshield to check for a cracked or loose manifold but it's not cracked or loose.

[PGFracing]

Mine would run if I would keep the rpms up around 3,000. It wouldn't start unless I gave it a little gas. From reading your posts it sounds very similar to mine. There is a post that says you can clean your EGR valve and it will work. More than likely your EGR valve is stuck open. It's not the easiest thing to get to. I had to use an air wrench along with a universal joint to break the bolts loose. I also had to remove the battery to get a good angle on the bolt. It's about an 1 hours work, 2-3 hours for a first timer. I'm nearly positive thats your problem.

[Kooldino]

Update:

If you install a J&S safeguard in between your EMS and the coils, you will NOT get the quick spark on "key on". I have a feeling that this will disable the POP from ever occuring.

Furthermore, when I tested this on the car with the safeguard, I wired the Safeguard to the red wire with the white stripe that powers the fuel pump. I found this wire under the cup holder.

So either the J&S Safeguard natively intercepts the quick spark, OR, you may be able to wire your EMS the that red/white fuel pump power wire to avoid the spark on "key on". Experiment and post your results here.

[Maxx Mazda]

So after reading all of your findings, I would suggest pulling the MPI injectors and looking to see if fuel squirts out when the MPI is switched on. That might help narrow it doen a bit.

[Kooldino]

IIRC, in the past I tried pulling the electronic plugs from the MPI injectors and it still did it.

[Maxx Mazda]

IIRC, in the past I tried pulling the electronic plugs from the MPI injectors and it still did it.


No ZZL for me.

I didn't try the injector unplug thing, only because it's a pain to do evey time (it would take about 3 mins to pull every time i wanted to do it...the plugs are hard to get to).

I jsut mean removing the injectors from the block physically, leave them plugged in and see if you get fuel squirting when you turn the key. You've narrowed it down to something with the MPI, correct?

[wicked]

I jsut mean removing the injectors from the block physically, leave them plugged in and see if you get fuel squirting when you turn the key. You've narrowed it down to something with the MPI, correct?



........or just use a test light.

[Kooldino]

I jsut mean removing the injectors from the block physically, leave them plugged in and see if you get fuel squirting when you turn the key. You've narrowed it down to something with the MPI, correct?

I see what you're saying. Worth a shot.

[Kooldino]

........or just use a test light.

Tried that before, got nothing.

[Fudgie]

Probably safer going with something like this:

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=11238&group_ID=1452&store=snapon-store&dir=catalog

The MPI fires the coils once when the key is flipped to the on position? Sounds like an old Mazda with a shitty cap and rotor that while cranking when cold would blow the airbox to bits due to crossfire. After the pop, does the car start and run ok, or is it missing?

[Fudgie]

Hard to tell with a testlight. Should have 12v at the injectors which is easy to check with the light, but connecting it in series at the injector connector and trying to watch and see if the circuit is grounded by the ecu can be diffcult.



........or just use a test light.

[Maxx Mazda]

So when you hear this pop does your boost gauge always twitch, every time?

[Kooldino]

Probably safer going with something like this:

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=11238&group_ID=1452&store=snapon-store&dir=catalog



Nice find! Now to find one for our injectors.



The MPI fires the coils once when the key is flipped to the on position?

Yes, one quick fire. Apparently, the Haltech does the same.


Sounds like an old Mazda with a shitty cap and rotor that while cranking when cold would blow the airbox to bits due to crossfire. After the pop, does the car start and run ok, or is it missing?

It would start and run, but it would run very rich for the first 20 seconds.

Once I changed to the 626 intake mani, it really hasn't happened nearly as frequently or intenseley as it used to.

It also used to occur more frequently in hot summer weather. I think fuel vapors play a role in this.

[Kooldino]

So when you hear this pop does your boost gauge always twitch, every time?

IIRC, it did.

It would often blow vac lines off of my intake manifold, and when the boost gauge twitched, it would pin the needle.

What's interesting is (if you go back and read all of the older posts) this same issue seems to happen with multiple EMSs, and multiple styles of injector setups (4 injectors in the stock place as well as 8 injector setups). However, I don't recall seeing it occur with pre-TB injector setups.

[Maxx Mazda]

One would think that the pre TB injectors fuel would be cut off by the TB, and thus not ignited...

[Fudgie]

The snap-on one that I have is adjustable so it can fit any connector. Good tool to have in the box. Interesting that the 626 manifold lessened it. Probably running rich because the afm was on fire! (flame)


Nice find! Now to find one for our injectors.




Yes, one quick fire. Apparently, the Haltech does the same.



It would start and run, but it would run very rich for the first 20 seconds.

Once I changed to the 626 intake mani, it really hasn't happened nearly as frequently or intenseley as it used to.

It also used to occur more frequently in hot summer weather. I think fuel vapors play a role in this.

[Kooldino]

One would think that the pre TB injectors fuel would be cut off by the TB, and thus not ignited...

Not only that, but with the car not running, they would just spray and run down the IC piping.

[Kooldino]

The snap-on one that I have is adjustable so it can fit any connector.
Oh, cool.


Good tool to have in the box. Interesting that the 626 manifold lessened it. Probably running rich because the afm was on fire! (flame)
lol

I have a theory that the VICS chambers would somehow trap extra vapors or something. Only hole in that is that while the car is off, the VICS butterflies are open.