Running lean and rich

[Kempi23]

My car is running lean and rich. Bank 1 STFT is 1.19 and Bank 2 STFT is 0.78. It’s giving me misfire codes P0300 and P0304. My car has catless headers, ported gt350 intake manifold with IMRC lockouts, gt350 TB, and 47 lb injectors. Starts up kind of rough but no loss of power and idles higher than normal right around 1000-1200. Literally just threw the codes after installing the gt350 mani and TB along with the injectors. Car is tuned by Lund. Anyone that can help?

Sponsored

 

[stangman638]

Did you get a tune for that manifold and injectors? You said threw a code after you installed those parts.

Did you contact your tuner at lund?

 

[EFI]

Almost sounds like a leaky injector on one side.

Can you go back to stock injectors and tune and see if it still does it?

 

[Kempi23]

Did you get a tune for that manifold and injectors? You said threw a code after you installed those parts.

Did you contact your tuner at lund?

Yes I got a tune for the Manifold with IMRC Lockouts, gt350 TB, and 47lb injectors. I contacted him and he said it wasn’t the tune and it was maybe a faulty o2 sensor or some wiring. He originally thought I switched the o2 sensors from bank to bank in the wiring harness but I didn’t touch them

 

[Avispa]

This is gonna sound weird, but try putting the stock tune back in and see if the STFTs balance out. You won't blow anything up, dumba$$ Ford dealer flashed the '16 back to stock before I bought it, with VMP 2.3, 52# injectors and Roush air box already installed. Managed a few months on it without damage before stumbling onto the tune issue. At least you can then isolate whether the tune is the problem with the trims.

 

[Kempi23]

This is gonna sound weird, but try putting the stock tune back in and see if the STFTs balance out. You won't blow anything up, dumba$$ Ford dealer flashed the '16 back to stock before I bought it, with VMP 2.3, 52# injectors and Roush air box already installed. Managed a few months on it without damage before stumbling onto the tune issue. At least you can then isolate whether the tune is the problem with the trims.

My tuner isolated it and said it was the trims

 

[Kempi23]

Quote on quote from the ford dealership, “We cannot do a diagnostics check because you have a tune on your car so we looked around and it could be a possible vacuum leak.” they tried charging me $130 for a diagnostics check and I was like “but you just said you couldn’t do one because I have a tune on my car!” Got an appointment for a performance shop next week. Car runs fine everywhere other than idle though after driving it

 

[ugstang17]

Have yu datalogged the tune after installing it and sent those logs back to the tuner for review as needed on ALL remote tuning session type tunes? If not that is where you need to begin. If they then tell you there is a mechanical or electrical issue with the car then you need to sort that out OR prove to them that the car is fine and to revisit their tune. You leave a lot of details out that leaves speculation open.

Trims are simply feedback response to what the tune is doing at a given RPM and AFR target. LTFT's will change accordingly over time to correct - or attempt - when STFT's are seen over about a 3% range for an extended period of time. If LTFT's go high or low enough a CEL will be generated. That is the simple version of that. So to state the trims are off...indicates that there may be a vacuum leak or some form of leak allowing unmetered air to get into the cylinder..........and your tuner is assuming based on all the work you have done that this is the case rather than his tune being off because he has likely "tuned Mustangs with this setup 1000's of times with no issues".

So you now have to prove to the tuner your car is sound before he will address anything. So..........keep in mind if he is right you may even have more than one issue with all of the mods you have made at one time.

Start by rechecking all of the intake fittings between the MAF and the intake. Air after the MAF is unmetered air and is not good.

P0304 is cylinder 4 misfire detected. The first thing to do is verify the fuel injector connections electrically. Then swap injector 3 with 4 and see if the P code changes to P0303 or stays P0304 (after clearing the codes, swapping injectors physically - not the electrical connections - and restarting the car). If it follows the injector you have a bad injector out of the box. IF it stays P0304 you have other issues.

Then start the car and let it idle down. If you have access to a propane torch crack the calve so that the gas barely escapes out. Then begin passing it around the intake runners - keeping it away from the airbox so you do not create a false scenario. IF there is a vacuum leak as the propane passes over, it will be sucked in and the car will begin to falter in idle. That indicates you have a vacuum leak and need to readdress the install on your intake manifold job. You can also use a butane lighter (wihtout striking it) as well and that may work. I have always used propane as shown me by an old school racer years ago.

Another issue may be that the IMRC plates (I think that is the acronym) in the intake may not be functioning correctly. This could effect and cause the imbalance on the trims as well. So verify that they are working. Wouldn't be the first time these have bittemnsomeone in the butt.

Idling high is possibly a symptom of a vacuum leak. You can see the vacuum on the LCD gauges display. It should be around 17" Hg at idle after warmup. Lund is known for setting their idle on 15+ cars up around 900 RPM as a standard. I had them lower mine to 750 but it took an act of congress to get Jon to comply. Thankfully I have a good speed shop that works very closely with Lund so I turn the car over to them and share what is going on and let them deal with Jon. IT seems to get better results since tuners ALL have a general consensus that no one knows anything about tuning theory but them.

Trims being lean on one side and rich on the other ARE characteristic of the O2 leads being swapped accidentally. However the trims should continue to rise on one side and lower on the other because the ECM is now fighting itself. So recheck and recheck again. The upper O2's will be the ones in question. Make sure you don't have a header leak in front of an O2 sensor as well. This will cause a false lean problem and cause trims to act up as well.

BTW - ECM, PCM, ECU all the same thing...the brain that the tune loaded is in.

Before I ever retune after mods I make sure that everything on the car is fresh. This includes fresh plugs, a full tank of 93 fuel with a can of booster in it just for the sake of the tuner trying to blame the fuel for false knock, a fresh oil change, a clean TB and MAF, and verification that ALL fittings on the intake tube between the MAF and intake on the Supercharger head unit are snug and not leaking. Takes a lot of starch out of the tuner's pants in doing so because this eliminates some very common excuses a tuner will have if tuning doesn't just fall right into place.

Good luck.

 

[Kempi23]

Have yu datalogged the tune after installing it and sent those logs back to the tuner for review as needed on ALL remote tuning session type tunes? If not that is where you need to begin. If they then tell you there is a mechanical or electrical issue with the car then you need to sort that out OR prove to them that the car is fine and to revisit their tune. You leave a lot of details out that leaves speculation open.

Trims are simply feedback response to what the tune is doing at a given RPM and AFR target. LTFT's will change accordingly over time to correct - or attempt - when STFT's are seen over about a 3% range for an extended period of time. If LTFT's go high or low enough a CEL will be generated. That is the simple version of that. So to state the trims are off...indicates that there may be a vacuum leak or some form of leak allowing unmetered air to get into the cylinder..........and your tuner is assuming based on all the work you have done that this is the case rather than his tune being off because he has likely "tuned Mustangs with this setup 1000's of times with no issues".

So you now have to prove to the tuner your car is sound before he will address anything. So..........keep in mind if he is right you may even have more than one issue with all of the mods you have made at one time.

Start by rechecking all of the intake fittings between the MAF and the intake. Air after the MAF is unmetered air and is not good.

P0304 is cylinder 4 misfire detected. The first thing to do is verify the fuel injector connections electrically. Then swap injector 3 with 4 and see if the P code changes to P0303 or stays P0304 (after clearing the codes, swapping injectors physically - not the electrical connections - and restarting the car). If it follows the injector you have a bad injector out of the box. IF it stays P0304 you have other issues.

Then start the car and let it idle down. If you have access to a propane torch crack the calve so that the gas barely escapes out. Then begin passing it around the intake runners - keeping it away from the airbox so you do not create a false scenario. IF there is a vacuum leak as the propane passes over, it will be sucked in and the car will begin to falter in idle. That indicates you have a vacuum leak and need to readdress the install on your intake manifold job. You can also use a butane lighter (wihtout striking it) as well and that may work. I have always used propane as shown me by an old school racer years ago.

Another issue may be that the IMRC plates (I think that is the acronym) in the intake may not be functioning correctly. This could effect and cause the imbalance on the trims as well. So verify that they are working. Wouldn't be the first time these have bittemnsomeone in the butt.

Idling high is possibly a symptom of a vacuum leak. You can see the vacuum on the LCD gauges display. It should be around 17" Hg at idle after warmup. Lund is known for setting their idle on 15+ cars up around 900 RPM as a standard. I had them lower mine to 750 but it took an act of congress to get Jon to comply. Thankfully I have a good speed shop that works very closely with Lund so I turn the car over to them and share what is going on and let them deal with Jon. IT seems to get better results since tuners ALL have a general consensus that no one knows anything about tuning theory but them.

Trims being lean on one side and rich on the other ARE characteristic of the O2 leads being swapped accidentally. However the trims should continue to rise on one side and lower on the other because the ECM is now fighting itself. So recheck and recheck again. The upper O2's will be the ones in question. Make sure you don't have a header leak in front of an O2 sensor as well. This will cause a false lean problem and cause trims to act up as well.

BTW - ECM, PCM, ECU all the same thing...the brain that the tune loaded is in.

Before I ever retune after mods I make sure that everything on the car is fresh. This includes fresh plugs, a full tank of 93 fuel with a can of booster in it just for the sake of the tuner trying to blame the fuel for false knock, a fresh oil change, a clean TB and MAF, and verification that ALL fittings on the intake tube between the MAF and intake on the Supercharger head unit are snug and not leaking. Takes a lot of starch out of the tuner's pants in doing so because this eliminates some very common excuses a tuner will have if tuning doesn't just fall right into place.

Good luck.

Now that’s a thorough response I was looking for. I will make sure to relook at everything, switch the injectors to check and see if the code changes to cylinder 3 and re go over the vacuum lines and intake. I drove the car around yesterday and the problems were only at idle. It was weird cause the weird idle characteristics were more so in park than just at a stop light.

 

[ugstang17]

http://iihs.net/fsm/?d=8&f=Adaptive Fuel DTC Diagnostic Techniques.pdf&p=1

This is from an older Ford manual but the basics are still the same. I forgot I had this. READ IT. Then observe your LTFT's in gauge mode on your ngauge. It may also help you further diagnose the issue.

Take one step at a time. Don't bounce around. The key to good thorough troubleshooting is to stay focused on a probable cause in question and see it through until it is ruled out. Then move on. Assuming something is okay will often times only result in wrongful diagnosis. I've spent over 35 years troubleshooting failed equipment. 95% of the time when i assumed something was fine on its mechanical side simply because it appeared to be okay on the electrical side I got bit in the butt. Be thorough, stay focused and take your time. Don't go off on a tangent simply because some "know-it-all" posts that he/she has the answer as if they were able to gaze into a crystal ball and see the answer. If it were that easy we would all be expert troubleshooters. Don't get rushed and/or let your ego dictate your direction. Use a meter where electrical troubleshooting may be required. Test lights can give false indications. Test lights can't check continuity or resistance across a coil. Here ends the sermon. Best of luck.

 

[Kempi23]

I went to go swap injectors 4 and 3 to see if it was possibly the injectors and it gave me a P025A code and my car goes up to 3k idle now. Starts very poorly then once it warms up, it goes to 3k idle. Swapping all injectors to see if it’ll go away.

 

[ugstang17]

Make sure you don't have leaks around the injector at the intake as another suggested. Inspect the o-rings for nicks or cuts. If present you need to replace the o-rings.

My guess is you started the car with the fuel pump relay out and let the car run until it died before swapping injectors as most do. I likely flagged that P025A alarm because it saw no action from the fuel pump at startup. Reset it. It is simply telling you that the ECM saw an open circuit on the fuel pump demand module which would have been caused by the pump not running more than likely.

 

[Nuked]

You can physically swap the front o2 sensors to see if the trims follow the sensor from bank to bank. This would tell you if there is a problem with one of the sensors.

 

[ugstang17]

You can physically swap the front o2 sensors to see if the trims follow the sensor from bank to bank. This would tell you if there is a problem with one of the sensors.

First things first. Resolve the misfire on cylinder 4 (P0304) which is on bank one -- the bank seeing the lean code as well -- then worry about the lean code if one still exists. A cylinder not firing can/will present a lean condition because the O2 in the mixture (hence O2 sensor) has not yet has not been spent and is still fully present in that wave as it passes by the sensor. Once that is resolved then you move on to the next phase if there is a need.

 

[BrianGT2015]

Check your O-rings on your injectors. Replace them. Had this same issue when I did my 18 manifold swap. An o ring had disappeared. number 7 cylinder. caused the same high idle issue. When I figured out the problem fixed it, everything was perfect.

Sponsored