Poor hot idle after a timing belt replacement

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protege5
evap code is not going to cause any kind of driveability issues. IT's just an emissions thing and will do NOTHING but turn on the check engine light.

Same with a cat code. The only time a cat causes a problem is if it gets completely clogged and the engine can't breathe. Otherwise it just turns on a light.

Both will cause you to fail emissions inspection if your state has that, but won't affect how the car runs or drives.
 
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2003 Mazda protoge 5
I know, we do have emissions in this state, at least through the end of the year then the program goes away but my car is an odd year vehicle so I'm due for its last inspection however.

Essentially odd year vehicles on odd years, even year models on even years is how they do the inspections.

Oh, got word that I should have the MAF by Thursday so can install that evening or Friday morning (off work Fridays through mid Sept at work).
 
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2003 Mazda protoge 5
Update, the MAF came in today and it's been replaced, the P0102/103 codes, gone, still have the P0300, at least for a time, with the Launch, I've cleared the codes before I left and shortly after that first clear, got the P0300 (randome misfire), cleared it again and eventually the light came on, again the P0300 and all this time the car has idles rough, but accelerates fine and at one point, I believe I got all tests for evap complete so that's a good sign.

Right now, after the third clear of codes (I think it is), the money light is remaining off, but sill idles like crap but runs mostly fine otherwise.

I understand it may take several drive cycles before the ECM will calibrate so will monitor it closely over the next several days. So before anyone asks, as it was also mentioned earlier in this post that I did replace the plugs 2 years ago, the wires a few weeks ago, just after the car sporadically began misfiring on the 4th of July, but with no codes. I even got a fresh gas cap because the evap was not completing, just to be safe as it was original to the car when new. I also replaced the air filter as well recently so it's new.

I'll try to see if there is an actual vacuum leak and will try to remove and spray the IAC valve as I came close to stripping out the JIS screws that hold the damn thing onto the throttle body. The car does not appear to smoke any either.
 
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2003 Mazda protoge 5
Since Friday, the MAF was installed and still have hot idle and as of yesterday, got a new code, P0172, rich condition with the P0300 and P0102 codes pending as of late yesterday.

I did attempt to clean the throttle body but will need to actually pull that and clean the backside, it's indeed dirty, just that the butterfly as closed from the air side looked clean-ish and when I do, I'll remove the idle air control valve and clean that and will try seeing if I have an injector issue (dripping, but the last I looked, the plugs were dry so will remove and have another look-see) and go from there.

The scanner has been an immense help here in helping me to track down the issue. It's sounding like either an air or fuel issue and will take it on the freeway to get it fully hot and see if the evap system completes.
 
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2003 Mazda protoge 5
Hello again, a quick update.

As of a minute or two ago, I still have the P0300 code, idle is bad once hot, but I finally passed the evap leak test I think for the first time since I got the scanner.

To do this, I drove the car roughly a 24 mile trip (12 miles both ways, give or take) and while it does still idle bad once warm, it did also seem to miss mildly a little bit at freeway speeds heading into Puyallup on the first leg of the trip but not on the way home.

So that is a bit of progress, I think anyway.

So the next course of action is pull the plugs and see what they look like now. then use the non flammable spray brakekleen to see if I can spot a vacuum leak anywhere and then try to remove the throttle body along with the IAC valve then remove that and get them both cleaned good and see what happens there. I will also once all that is done, add seafoam to the tank and see if that helps (namely to clean the injectors in case they are indeed a bit dirty.

Anything else I should do next?
 
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2003 Mazda protoge 5
Hello again, a quick update.

As of a minute or two ago, I still have the P0300 code, idle is bad once hot, but I finally passed the evap leak test I think for the first time since I got the scanner.

To do this, I drove the car roughly a 24 mile trip (12 miles both ways, give or take) and while it does still idle bad once warm, it did also seem to miss mildly a little bit at freeway speeds heading into Puyallup on the first leg of the trip but not on the way home.

So that is a bit of progress, I think anyway.

So the next course of action is pull the plugs and see what they look like now. then use the non flammable spray brakekleen to see if I can spot a vacuum leak anywhere and then try to remove the throttle body along with the IAC valve then remove that and get them both cleaned good and see what happens there. I will also once all that is done, add seafoam to the tank and see if that helps (namely to clean the injectors in case they are indeed a bit dirty.

Anything else I should do next?
 

pcb

The Diagram Dude
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2002 MP5
I remember PMing a guy from Oklahoma a bunch of years back.
His car would only misfire after a full heat soak.
He even brought an oscilloscope home from work to test the inputs on the ECU.
He was just about to take his car to the dealer when he decided to put his old original factory coils back on his car to try them and his misfiring stopped.

His brand new coils would crap out at high temperatures.

If you only have the "occasional" misfire, it may not foul the plugs but be enough to throw the misfire code and give you a crappy idle.

I'm thinking your coils are shorting to the valve cover.

You could test your car in the dark with a spray bottle of water.
I bet you'll see blue sparks.
 

pcb

The Diagram Dude
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2002 MP5
The bench test for the coils is useless,(unless they do fail)
They will almost always pass but then fail on your car.

 

pcb

The Diagram Dude
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2002 MP5
I replaced my coils as soon as I joined this site after hearing about all the strange and weird ways they were messing with our car.

I keep my old coils in the trunk just in case my car goes nuts for no apparent reason.
 

pcb

The Diagram Dude
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2002 MP5
... then use the non flammable spray brakekleen to see if I can spot a vacuum leak..

I'm not sure but you might want to use carb cleaner?

The non-flammable stuff may not increase your idle and it might not be safe for plastic and rubber (just guessing, I don't know?)
 
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2003 Mazda protoge 5
I also have the brake cleen and carb cleaner and can try that, once I get the reasonably clean throttle body back in and see how the car runs (or not). :)

But at the very least, it'll be cleaner at worst, it'll make things worse.

Then it's the coils as all 4 plugs had not changed and seafoam goes in the tank, just to be safe (clean injectors and all that).

Wish me luck!

BTW, I agree that the the coils are likely playing tricks with us, but my buddy even briefly thought so too as he had a similar issue with his 2001 F150 and I forget what was the issue but it had coils for every plug, not the wasted spark we have on our cars.

So back to the grind!
 
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2003 Mazda protoge 5
Well, the car starts, runs well, as long as the idle is high but once it gets down around 800-900, it's lumpy idle still.

But it runs, accelerates and all that. Put half a can of Seafoam in the tank to see if that helps any.

And I just got back from a quick errand and it wants to die when still in gear (automatic), but once in neutral, the idle stays at roughly 1500rpm a lot of the time but runs OK overall otherwise. I will need to pop the throttle body off and replace the gasket as part of it came off and it was too late to go get a fresh one so some extra air may be leaking in there. No leaks otherwise was found.

So now I'm driving not quite half a tank with Seafoam in it at the moment. The STFT is way high, but the LTFT is mostly at 0.0%, where it should be, unless I accelerate then it goes high momentarily but seems to just drop back to 0.0%, according to the live data stream of the Launch.
 

pcb

The Diagram Dude
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2002 MP5
Well, the car starts, runs well, as long as the idle is high but once it gets down around 800-900, it's lumpy idle still.
That's your IAC, the ECU hands off control of the idle to the IAC after the engine warms up and your RPM's drop.
 
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2003 Mazda protoge 5
Question, do you know of a way to remove the stubborn and also chowdered JIS screw?

Even with the throttle body off, I still could not find a driver to fit snuggly into the stripped out X head on that one screw. I was able to break the others free though without issue.

I wonder if it was serviced/replaced at one point and someone reefed on the screws as they were tight.

These are a pain to get off with the TB on the car, especially the back left screw, which is the chowdered one.

Otherwise I'll Google how. Won't be able to do anything until Friday when I'm off (thanks to a 4 day work week during the summer).
 

pcb

The Diagram Dude
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2002 MP5
Perhaps you could use a dremel tool with a cut-off wheel and cut a slot in it then use a flat head screwdriver.
If you can fit it in there..
 

pcb

The Diagram Dude
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2002 MP5
Another trick I remember is to put your car in gear then push it forward (or back, .. I forget) then block the wheels.
That rolls the engine in the engine bay a bit and gives you more clearance.
 
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2003 Mazda protoge 5
I'll probably go the Dremel route as I do have to remove the throttle body to replace the gasket come Friday anyway and that's the easiest way to access that screw.

Meanwhile, I can still drive the car the short distance to work until then (less than 10 minutes to and from work).

Thanks.
 

pcb

The Diagram Dude
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2002 MP5
Perhaps you could use a dremel tool with a cut-off wheel and cut a slot in it then use a flat head screwdriver.
If you can fit it in there..
If that doesn't work, you could grind the head of the screw off then remove the IAC.
You should have 4-5 threads showing that you should be able to grab with a vise-grip.
 
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2003 Mazda protoge 5
Yeah, I think getting something to bite the screw so it can be removed is best, however, today, my car runs like shit, can't idle at all with the transmission in gear and not always when in neutral either so a bit of a foot and dance to keep from dying and then restart, it does start usually with no issue, but right now, the codes are P0102, if memory serves, low air flow from the MAF but now the P0304 misfire is back, despite the coils swapped.

Add to that, I did check the plugs yesterday and they were bone dry, tan but the end of the threads are black, but not oily at all, not wet with gas. Oil in engine does not look diluted with gas and it does chug now on acceleration, but I know 2 problems at the moment, the throttle body needs a new gasket, can't get to that until Friday morning and the IAC may be kaput, at least semi anyway.

Before leaving work for home, I did double check to ensure everything was plugged in, yep they all were (electrically) as I thought I had done.

However on the way home, the check engine light began flashing so I'm just hoping it's part of the learning process and will improve at least somewhat in the next day or two.
 
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2003 Mazda protoge 5
I have decided that if the prices locally aren't too out of whack, to order up the parts for pickup on Friday and install them and hope that will solve all my ills.

The new gasket for the throttle body
New IAC and its gasket
Two new coils, just to be safe and may also go ahead and replace the plugs if need be since the current set has been hammered for almost a month with bad idling and see how things improve though they generally look fine and not oily or wet, just tan with a bit of black around the end of the threads, normal looking in fact. I will try to remember to check the coils when nearly dark and see if I spot sparkies, if so, they are one of the culprits.

In the meantime, gotta get to and from work, fortunately, it's not far but can't do anything until I drop by my credit union and get a new debit card, mine somehow got compromised sometime between the 17th of this month and last weekend but my Mint credit monitoring payment went through on the 20th.

Someone tried to make a $5000 payment on something, I forget what that my CU caught so money is locked up tight and fortunately, the branches are open until 6pm and I get off work at 5, though I might sneak out a few minutes early.
 
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