Jumped a tooth.

[Edyuly]

Maybe someone can help me out. I am builing my 15gt by adding a Paxton supercharger,oil pump gear and timing chain sprocket from MMR. My installer finished installing everything and while data logging Lund who is tuning it discovered something is off with the timing of the car. So my builder said it must have jumped a tooth at start up and Lund agreed. Is there something to check or way to install to make sure this does not happen again. Can my engine be hurt from this? He was just doing the idle and 1500rpm data log?

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[jasonstang]

Improper length chain? Chain tensioner seal leak?

 

[65ffr]

Ignition or cam timing?
a timing chain cannot 'jump' a tooth during startup unless there are SERIOUS issues (like broken/missing gear teeth etc). Sounds like installation was messed up. Ask builder how it could have jumped a tooth I'd like to hear his line of reasoning.

 

[Reds197]

Assembled wrong. No way around it especially with only 1500 rpm. Sucks but have it redone and move on.

 

[Excelerater]

you may have bent some valves ,I would check that out ASAP

 

[Inigo]

Installation error. Do not drive the car. Get that worked checked by a different mechanic and talk to the first installer about any and all damages.



If you need any assistance pm me. What area are you in?

 

[Edyuly]

UPDATE

So my builder took everything apart and timing chain is on correct . My problem is that Bank 1 short term fuel trim is trimming richer than bank 2 by .12 average. and Lund will not tune it that way. He changed fuel injectors from one side to the other installed 2 new 02 sensors and the problem is still there is there something we are overlooking? The car ran fine prior to the install but never checked banks prior to this install. Any help would be greatly appreciated.

 

[Inigo]

UPDATE

So my builder took everything apart and timing chain is on correct . My problem is that Bank 1 short term fuel trim is trimming richer than bank 2 by .12 average. and Lund will not tune it that way. He changed fuel injectors from one side to the other installed 2 new 02 sensors and the problem is still there is there something we are overlooking? The car ran fine prior to the install but never checked banks prior to this install. Any help would be greatly appreciated.

It is important to get the installation verified by a unbiased eye. Every mechanic will defend there work. How did your builder verify the cams and crank were truly in time? The chain could be installed correctly but installed one tooth off. How did your mechanic check that the timing was accurate regardless of the chains physical position? The reason I ask is because its highly likely that he never got the cam phasers and crank marks to line up. This means he had to mark the sprockets and depending on how he did the installation, its possible the assembly is actually not correct.

When I did mine, I had to pay extra care not to move the crank or cam. I also made sure to index the chain and gears at multiple points once the engine was set tdc. Making sure that the engine is not 180 out is also important during this step. One thing to note for anyone performing this job is that the crank gear does not have to be influenced in order to remove the gear. The chains provide enough slack to move around the teeth for removal once the tensioner is removed.

I would suggest you have the timing verified.
What does your timing advance look like on bank 1 vs 2?

 

[ArtQ]

Turn crank till key is at the 5 O'clock postion and install left chain so colored link aligns with timing mark.

Turn crankshaft one complete revolution

Turn crankshaft till key is at 12 O'clock position

Align colored link with timing mark on crank gear

Align colored link with right cam gear

You can check the timing without using the colored links if you count 33 links between the marks.

 

[Edyuly]

ArtQ is my installer. He just joined the site to post some informative pics and try to see if anyone has a solution for my problem that he has not tried.

 

[Reds197]

The pictures look correct. You will get a timing code if its installed incorrectly. Are you getting any codes?

 

[djt81185]

UPDATE

So my builder took everything apart and timing chain is on correct . My problem is that Bank 1 short term fuel trim is trimming richer than bank 2 by .12 average. and Lund will not tune it that way. He changed fuel injectors from one side to the other installed 2 new 02 sensors and the problem is still there is there something we are overlooking? The car ran fine prior to the install but never checked banks prior to this install. Any help would be greatly appreciated.

I'd check for intake manifold leaks. Had a similar issue on a big turbo trans am after I tore it apart and ended up being the intake manifold flange was slightly warped. Had to run 2 gaskets and crank em down to get it to seal up.

Check to make sure all bolts are tight and none of the rubber couplers/seals are missing or torn. Also check around the sensors. You can either use a smoke machine or lightly spray carb cleaner around the engine while running just don't get it on anything hot or directly into the air inlet lol.

 

[Plimmer]

I'm guessing here, so just throwing out ideas for you:
1. Did you drive the car at a gentle cruise for at least 20 or so miles to give the short term and long term trims a chance to relearn and settle down, not sure if your tuner turned off LTFT learning, but you might need to just gently drive it around to let the trims settle
2. If they are still off then you might have an air leak after the MAF and more likely on the bank where the trims are adding fuel. Usually the air leak is more obvious at idle and is less obvious at higher throttles.

 

[ArtQ]

Initially it set a P2196 code.

P2196 - O2 Sensor Signal Biased/Stuck Rich - Bank 1, Sensor 1​

Description:​

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A universal heated oxygen sensor bank 1, sensor 1 (HO2S11) indicating rich at the end of a test is trying to
correct for an over rich condition. This DTC sets when the fuel control system no longer detects switching for a
calibrated amount of time.​

Possible Causes:​

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• Water in the harness connector​

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UO2SPC11 circuit open​

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Corrosion​

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Incorrect connections​

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Excessive fuel pressure​

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Leaking or contaminated fuel injectors​

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EVAP purge valve stuck open​

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Biased MAP sensor signal​

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Incorrect learned ethanol content​

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Contaminated MAF sensor (if equipped)​

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Positive crankcase ventilation (PCV) system​

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Contaminated oil​

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Oil overfill​

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Camshaft timing​

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Damaged universal HO2S11​

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Damaged PCM​

Diagnostic

The more I run it the closer they align. The left bank (2) is running close to 1.0 STFT. The right bank (1) is running .87-.92. I was thinking the same about LTFT slowly pulling that side closer to bank 2. The engine runs smooth and revs fine. You wouldn't know there was a problem. The right bank is reading richer in AF. If it was an air leak prior to the intake, I would expect to see a lean condition. I wonder if the right IMRC is sticking. If I start from an idle the STFT is split and stays that way. If I take it up to 3000 rpm hold it there for a few seconds, then very gently bring it back to idle the STFT are matched but the bank to bank AFR is off showing the right bank rich. It will stay that way till I do a quick rev then goes back to split STFT but AFR matched.

 

[Lonmon]

Can you switch the bank 1 and 2 sensors and see if the code or bias switches to the other bank? Not sure if they are the same but that would rule in or out the a/f sensor.

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