Poor hot idle after a timing belt replacement

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2003 Mazda protoge 5
Hello, first time here, but not new to forums in general and I have an issue with my 2003 Mazda Protege 5 that I bought second hand in 2012 and it's been largely reliable so far, except recently when what I thought was a timing belt snapping but ended up being the tensionor spring instead but replaced the belt anyway as it was likely due since I had NO idea when the original one was replaced, guessing sometime between 85K 95K, 100K at latest as I bought the car with 110,680 miles on it and now has 187+K on it.

Some back history; the car had been running great until the pas 3 years when every so often, very sporadically, like 3 times it's stalled while coming to a stop but a quick flick of the key after putting the automatic into neutral and it'll restart right back up. No codes present (no money light on) and not do it for months, then it may do it once and not do it again for a long while.

Then on the 4th of July a few weeks ago, I drove an hour and a half up the Washington state peninsula to Bainbridge Island for the day as I have a sister that lives on the island with her husband and the car kept sporadically sputtering, 2 shakes and keep going, no light, it was very random but did it every so often going up and coming back but the money light never turned on, if a code was present, it was pending.

Then that weekend the 6th, decided to replace the spark plug wires, the plugs looked good, were replaced a couple of years ago, tan with the little black around the end of the threads but dry and non oily, all 4 were even in that regard. On the 12th, went to retrieve a friend's dog that I was taking care of while they were in Europe who'd escaped from my backyard earlier that day and a friend had retrieved from the pound and dropped off at his family's home to be picked up by me and as I headed over to get him, cresting a hill about maybe 2 blocks from their street, the motor shuts down, all idiot lights come on, so hit neutral and tried to start while the car coasted along, it cranked, but not start so coasted into their street and to the side of the road overnight and borrowed my friend's car and got home, with dog. A mutual friend came over the next day and we got it into my friend's driveway to begin replacing the timing belt that I purchased that morning.

By Monday evening, I had the car running and back on the road, seemed to run fine, no money light (so I thought) but that changed by the next day, the money light was on and the car as it warmed up began to misfire once at hot idle. Acceleration has been strong and runs fine once I got above 2000rpms but once at idle, sputtering and missing.

Things I've done since. New air filter as the old one was dirty (in case it was an issue and was due anyway, helped a little) but by the next day, the idle/performance got much worse to the point that the money light would flash, then go back to steady and then stay flashing for much of a day before returning to solid on as things improved a bit, checked plugs again, wires coils seem OK as I unplug one coil and the car's performance got worse with both coils performing similarly, tried to suss out if a vacuum leak, so far not finding anything there. A sensor on the top of the intake hose between filter box and the throttle body does not change anything when I unplug it (what is it anyway? has 2 hoses running from it), the idle air control seems OK as I unplug and the car immediately dies and tried to get that off but the screws are so tight that I may have stripped the phillips head on one of the screws to make sure it's clean. The butterfly in the throttle body is very clean, BTW. Had to replace the hose to throttle body and air filter housing as I broke the little plastic tube mount for a hose going to the valve cover and prior unit had been replaced a few years back as the original one had split. No change.

Went to Autozone (in the US) and got a P0300, generic random misfire one day after I got the car back on the road from the initial belt change. No other codes present according to their scanner. Now, I'm running blind here as when I did the belt replacement, I ensured the marks were set right on both cams and the crank, however, I got the I and E marks facing each other, the intake is more or less level, the exhaust is a tad lower but they face each other with the intake at 7:00, the E at 5:00 on opposite cams, will that make a difference? I know the crank is dead on with the notch in the crank case but have NO way to tell without a scope, much less an OBDII reader with graphing ability (NE, the Launch Creader V+) but have time and patience but a lack of funds to do this and am trying to avoid having to tear into the motor, just to make an adjustment of the belt itself if not necessary.

I made the mistake of asking Autozone what the code meant, and they looked up on their site and said the most likely is the EGR valve, but at $141, um, no thank you. A quick question at another shop said that it's not likely for it to suddenly not work once the belt was replaced if it appeared to be working before.

The gal I asked at Advanced Auto said it's looking like either spark or an air issue, and I'm beginning to suspect that to a degree, but without a scan for timing I have no real way to know for certain.

Any suggestions? BTW, Napa says my car is interference, FS/DE 2.0L 4, Virtually all other sources say non interfence, I do have a clattering lifter (seems to be at one cylinder) but that would not cause this issue, would it?

Thanks! Sorry for the long post, but needed to give the backstory as it may provide a clue(s).

PS: Tried to upload a photo I took of the cams after I got the new belt on, but the forum kept throwing an error during downloading from my phone (it's a Jpg photo). Anyway, the Intake cam is level, the Exhaust is a tad lower than the intake cam, any issues there?

Thanks again!
 
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Welcome to the forums. Since the motor runs well most of the time, the timing belt is likely correctly installed. The crank pulley notch should point directly upward, while the two cam index marks point toward each other. The exhaust pointer will be slightly lower than level. My motor's cams were oriented as you describe. Photo
I would look for a vacuum leak between the MAF sensor and the intake, leak around the intake manifold, vacuum hoses that are cracked or leaking, or possibly low fuel pressure from the in-tank pump.
 
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Thank you!

I will do some more checking. The air hose from the filter box to the throttle body got replaced over the past weekend when I accidentally broke the little plastic nipple that a vacuum hose (I think it is) that goes from the hose to the valve cover broke on me so that's good, but will check more and that original one I broke was replaced about 5 years ago anyhow when the original one to the car split. Had that done via Midas near work at the time.

I will also try a repair shop tomorrow that I hear is good and may have the proper scan tool to see what other codes may be present other than the generic ones (IE, specific to Mazda to know what sensors etc may be at fault, if any).

Thanks for confirming that my timing is likely OK, just something else if wonky but nothing drastic. I'll check the intake to see what exactly may be at issue there.

This is where a full scan for all codes, not just OBDII will help I'm sure.

However, I had at that point swapped coils to see if the misfire in Cyl 4 moved to Cyl 2 but so far not seen that code as yet as I cleared them as the code for cyl 4 misfire had not changed to see if it changes when the codes reappear. So far, the MAF sensor codes came back first, then eventually the P0300 random misfire came back but that was it so far as of yesterday.

Any ideas?
 
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Here is an update of my issues.

Picked up the Launch Creader V+ scan tool the other day and have done some scanning and got 5 codes and they are as follows;

P0102, MAF low
P0103 MAF voltage circuit too high
P0230 Camshaft sensor (mine has scratches on the surface, bad?)
P0300 (obviously as it's the general random misfire)
P0304 Cylinder 4 misfire
P0401 EGR flow insufficient

So it's looking like both vacuum and spark issues.

Need to verify, cylinder #'s are 1,2,3,4, left to right with the firing order 1,3,4,2, correct?

So I'll check Cylinder 4's plug and see if it's now fouled, or not and then swap coils to see if issue moves, or not and look for carbon tracking. Don't recall seeing carbon tracking before.

I'll dig around for the EGR valve and check to ensure its vacuum hose is not cracked or kinked in some way.

I know one bolt is missing that holds the MAF sensor on, it fell out after I removed the valve to look at it. It didn't look dirty but maybe a good spray is necessary and find a proper bolt to ensure it stays mounted. I could have sworn I tightened it down snugly, guess not?

Some research has lead to what is some causes of each symptom and some of these, if not all are related it appears.

One thing I read about the P0340, cam censor is sometimes the crank can cause this code too when its at fault too if the cam sensor replacement does not clear that code.

So the plan of attack is to do the easiest things first, clear codes and see which ones return, or not.

I'll pick up a can of MAF cleaner to see if that solves that issue (again, or not).

Car still idles hot badly but powers up otherwise fine, just occasionally stumbles a little initially after recovering from sputtering at idle, but once it does, it drives largely fine.
 
I remember one guy that had a hard time starting his car when it was hot.

It turned out to be his ECT sensor.
It was covered in crap and the ECU was getting a false reading.

He removed it and cleaned it and that fixed his car.

He had no code, because the ECU didn't know the info was bad.
 
PCB, interesting, though I had the radiator replaced 2 years ago and I can't recall if that sensor had been replaced and I believe I spotted it checking codes etc yesterday (and cleaning the MAF sensor while at it) to see if that helped things. Not sure if it did.

After I got it sprayed and reinstalled and plugged back in, started the car (starts fine, barely a flick of the key and it fires right up when warm) and then unplugged the sensor, motor kept running but once I plugged it back in, it died. I guess it's fine?

As of this morning I now have 3 codes, the P0300 (not the first to come back this time) and the two MAF codes did come back first, then eventually the P0300 came back. This is where having the scanner has paid for itself, being able to check codes and see what's changed, or not.

I cleared the codes to see if it changes the misfire in cylinder from Cyl 4 to Cyl 2 as I swapped coils and right away, the codes didn't change, still said misfire in Cyl 4 so cleared them and so far not gotten those to come up as yet, nor the rest of the 5 codes.

Car still idles like poo when hot though.

Any ideas?
 
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I made the mistake of asking Autozone what the code meant, and they looked upon their site and said the most likely is the EGR valve, but at $141, um, no thank you. A quick question at another shop said that it's not likely for it to suddenly not work once the belt was replaced if it appeared to be working before.

A lot of people here on the forum have had problems with their EGR.

Some guys have to remove it and clean it every year.

They get stuck in one of their positions and create the driveability problems you describe.

Sometimes not opening all the way or closing all the way or stuck in one position. Then it releases again and works for a while longer.

PS. They are not Philips screws. They are JIS.

Phillips will strip a JIS screw.
 
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Remember too that the car needs to relearn how to idle the car every time the battery is disconnected. It takes about 100 miles of driving.
 
Coils are another big issue for our car and like to fail when they feel like it, sometimes only after a full heat soak or certain RPMs or engine loads.

If you have a fouled cylinder, swapping coils may make the swapped coil fail.
 
You may have partially fouled injectors too.

Half a can of Seafoam in your gas may help.

It's cheap and easy and could help.
 
The two MAF codes are not generic so keep checking for an intake leak.

Check your intake tube for cracks.
Almost everyone here has had to replace it.
 
The little marks on the intake and exhaust cams should be dead on.
If they are off by what looks like one tooth on the belt, then your timing is off.

They use the same cam gear for both the intake and exhaust camshafts so they are labeled for both.



There are marks on the backside of the gears that line up perfectly with the top of the cylinder head when the valve cover is removed.

You can look straight across to see it easier.

Make sure you rotate your engine over twice by the crank bolt before you check the timing.
 
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Intake tube has been replaced twice, the first was the original when the car was then 13 years old and had literally split at the ribbing and did cause driveability issues as the car would occasionally violently misfire from too much air all at once I think.

I replaced it 2 weekends ago when I accidentally broke the nipple towards the throttle body end for a hose that goes to the side of the valve cover. It's a dorman part from Autozone and looks cheap with a hazy look to the rubber.

But will check for leaks in the intake.

None of my plugs have fouled though I did pop the 4th cylinder plug out yesterday and it looks dry, not fouled in any way. Took a photo but forgot to post. The other 3 have been similar but will check them all again to ensure none have changed and will try to remember to double check for carbon tracking, of which I forgot to do for the 4th cylinder plug, which appeared to have been pregapped properly when I put them in about 2 years ago.

I'll keep note of the other comments you brought up.

Bad injectors have crossed my mind but the plugs would be wet when removed, right? They've been bone dry, a tad black around the threads and tan at the electrodes but dry.
 
Interesting you bring up the timing marks for the cams. Midnightcoder said that his were a touch lower than true level and if I recall right, even Tyler of Tyler's Neighborhood Garage on YT had one cam (exhaust if I recall, just mike Midnightcoder and mine) be like that too when he did a slightly older (1999) Protege ES sedan a few years back and it ran fine. he's done 2 of these, BTW.

Besides from discussing this with several people, since once it hits 1500-2000rpms, the motor runs fine and pulls strong so it likely is fine as Midnightcoder indicated as well and I'm inclined to think so as well.

Other than the hot idle, the car runs great with no driveability issues, unless it occasionally stumbles initially for a moment recovering from a bad idle from a dead stop, but once it recovers, it picks up steam and goes.
 
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It's probably just relearning how to idle your car.

My car stumbles and nearly stalls after I disconnect the battery.

If your car starts flashing your cel again, cleaning or replacing you EGR would probably be a good idea.

If your timing marks are off by a mm or so, you're fine. Just not a whole tooth.

Your MAF codes still need to be addressed though.
 
I never did disconnect the battery, but accidentally did leave the ignition in the "on" position while working on the belt and it did spank the battery enough to where it was 11-12 Volts though so a jump start got it going again. Yes, it did upset the settings on my head unit (not factory, was long gone by the time I bought the car).

I've had to replace the battery in the past and never recalled it running this bad before so who knows.

I need to do errands this morning locally so we'll see how it fares. I did do a quick run on the freeway about a week ago and it did fine dong at least 60mph. I'm hoping the codes update today so I can see if there is indeed an issue with the coils or not, but will investigate the MAF more.

Can't seem to get the EVAP to pass, the code reader just initializes the test and it says failed, not specifics mentioned but one of the biggest things (and the cheapest is a fresh gas cap) so I may try that, just in case it is not to spec while out.
 
Can't seem to get the EVAP to pass, the code reader just initializes the test and it says failed, not specifics mentioned but one of the biggest things (and the cheapest is a fresh gas cap) so I may try that, just in case it is not to spec while out.

I don't think you can fail your EVAP without some code associated with it.

Perhaps the monitor wasn't ready so it just said fail.



Make sure you're going the right speed with the right RPM and proper amount of gas, or you'll never finish the test.
 
If you only rubbed the codes, all your Intermittent Monitors should have remained finished.

Disconnecting power resets the ECU and all monitors start over.

Or maybe your Code reader reset the ECU??
 
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