I am running a clean 90-100hp tune and find my truck limping the tranny for a while before the truck gets warmed up. It is not throwing any engine lights or codes. just cuts out and wont let me pass 1800ish RPMs. Any clue what is causing this? I have had trouble with a p0089 code but tweaked with a table and my lift pump and got rid of that code. Tranny is still strong but nowhere near being a built up!
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Limping mild tune
- Thread starter phil87
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I would start by logging your truck when the issue is happening. It would help us help you.
when the truck limps does the tranny lock into 3rd or 4th gear? or is it just a lack of power from the engine. if the tranny limps it will stay in the high gear even if you stop. if its an engine limp the tranny will shift but wont rev over 1800 to 2000 rpm. we are gonna need to know for sure which its doing to further diagnose the problem. coudl be a simple loose connection somewhere. since you have an aftermarket CP3 perhaps someone missed something like locking down one of the bales for the main wiring harness. just some thoughts on places to look for the problem
durallymax
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log the difference in commanded vs actual.
If it goes over a 20mpa differece(up to 2200RPM) or 30mpa difference over 2200RPM< it will put the engine into protection stage 1 which limits fueling to 2,000RPM.
The tranny will still shift though.
you eill most likely not get a code though.
If it is the issue do the following.
Go to table C1806 and make sure that it is set to no default
Go to table C1802 and raise the allowable differences
too much pulse width will cause the rails to loose too much pressure but you said the tune is clean so it doesnt sound like that is the issue unless your CP3 is bad.
If it goes over a 20mpa differece(up to 2200RPM) or 30mpa difference over 2200RPM< it will put the engine into protection stage 1 which limits fueling to 2,000RPM.
The tranny will still shift though.
you eill most likely not get a code though.
If it is the issue do the following.
Go to table C1806 and make sure that it is set to no default
Go to table C1802 and raise the allowable differences
too much pulse width will cause the rails to loose too much pressure but you said the tune is clean so it doesnt sound like that is the issue unless your CP3 is bad.
durallymax
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also its hard to limp a tranny before the truck is warmed up because it will not lock the torque convertor unless the coolant temp is over 140*.
durallymax
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yes if it is supplying more than the commanded FRP then it will all send the motor into protection mode. Im not near my EFI Live right now but the Fuel pressure too high table is right next to the low table.
durallymax
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im sure a loose connection would cause many other problems as well
durallymax
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I just looked through a stock tune and saw that fuel pressure is changing quite a bit depending on ECT. Its very possibel his modified CP3 is flowing too much fuel at low ECT causing the engine to limp.
durallymax
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uin laymens terms he needs to log his difference between commanded and actual FRP. Then tell us what he gets. If its too high he needs to alter the allowable difference
either alter the difference or control the difference with the commanded current. telling the ecm that its ok to be off by 40 mpa instead of 20 mpa could cause other issues or quirks that arent desirable, where correcting the difference might help keep the ecm happy as well as the motor
durallymax
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Well true, but Ive never tuned with a modified CP3 so I figured a little trickery would help get him by while he has time to sit down and alter it.
If it is supplying to much fuel find out at what RPM and then go into the fuel pressure table and adjust it accordingly until it is right. This will take awhile to get it perfect.
If it is supplying to much fuel find out at what RPM and then go into the fuel pressure table and adjust it accordingly until it is right. This will take awhile to get it perfect.
Yeah sorry guys all This has come at the end of the semester so I have been righting papers and submitting a senior project proposal. I will log my truck when it does it. It still shifts the tranny, its not locking in 4th or anything. It just limits my rpms I will still see about 60MPH but accelerates very slowly.
You all have given me a lot to start w/. I will Log the Actual and Commanded Fuel?! and see what I get. I have ajusted the allowable milliamps before with no result maybe I need more??
Also the wicked pump runs 18ish% more flow I was throwing codes like p0088 and p0089 a few months back but think I worked those kinks out. *Could those codes come from my modCP3 or lift pump?
Also the wicked pump runs 18ish% more flow I was throwing codes like p0088 and p0089 a few months back but think I worked those kinks out. *Could those codes come from my modCP3 or lift pump?