Need help possible bad pcm?
11-12-2005, 05:02 PM
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Need help possible bad pcm? Well its been about a week since i messed with the car at the track and thats when this bug i have started.On my last pass of the day i had to get out of the throttle for a issue i had with my steering anyways when i was coming down the return road i notice the car was running like ****.We loaded it up brought it home is when we kenw we had a problem.The car stumbles and won't rev up.This is what we have done so far.Changed map,maf,swaped coils and wires cylinder leak down check all rockers pulled intake check for cracks or bad gaskets.checked all grounds on back of left head,fuel pressure 58 psi tryed reflashing the computer with a diffrent file and even put diffrent injectors in it.Im starting to think its a bad pcm.BTW this car has been tuned all season open loop so o2s are a thing of the past.It runs so poorly you couldn't even get it out of my driveway.Any thoughts on what i might wanna check.Thanks mike
11-12-2005, 06:24 PM
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Timming and fuel look good.I use efi software and i wonder when you look at timing values while its running if its commanded timming or actual.Im wondering if my reluctar ring on the crank some how slipped or moved 
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11-12-2005, 11:25 PM
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like you said the Crank sensor might have moved or slipped when you were hammering down the strip and its now got the wrong timing.
When you have the car idling what is the wideband reading
What does the car do when you try and rev it
Could it be a blocked exhaust or loose spark plug lead
When you have the car idling what is the wideband reading
What does the car do when you try and rev it
Could it be a blocked exhaust or loose spark plug lead
11-12-2005, 11:52 PM
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Originally Posted by SikHabibBroCuz
like you said the Crank sensor might have moved or slipped when you were hammering down the strip and its now got the wrong timing.
When you have the car idling what is the wideband reading
What does the car do when you try and rev it
Could it be a blocked exhaust or loose spark plug lead
When you have the car idling what is the wideband reading
What does the car do when you try and rev it
Could it be a blocked exhaust or loose spark plug lead
Car revs very poorly
3 in borla true duals.
11-13-2005, 01:40 PM
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Okay couple more questions.Can you have a bad pcm without throwing any codes.And if the maf was going bad or on the way out will that still work witout a code.I really hate to get a pcm and find out that not the problem I think im going to set the car in sd mode and see if its better.Now i just have to fugure how to set it to sd mode 
I think im going to set the car in sd mode and see if its better.Now i just have to fugure how to set it to sd mode 
11-23-2005, 12:09 AM
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man thats wacked. Have you check compression on all cylinders?
Air filter could have collapsed and is blocking air intake
Have you checked the water temp sensor?? maybe one of the wires broke off or the sensor **** its self and the engine is thinking its overheated and is shutting off cylinders. I know its a long shot but it sounds like youve tried everything else
Air filter could have collapsed and is blocking air intake
Have you checked the water temp sensor?? maybe one of the wires broke off or the sensor **** its self and the engine is thinking its overheated and is shutting off cylinders. I know its a long shot but it sounds like youve tried everything else
11-23-2005, 10:07 AM
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Originally Posted by SikHabibBroCuz
man thats wacked. Have you check compression on all cylinders?
Air filter could have collapsed and is blocking air intake
Have you checked the water temp sensor?? maybe one of the wires broke off or the sensor **** its self and the engine is thinking its overheated and is shutting off cylinders. I know its a long shot but it sounds like youve tried everything else
Air filter could have collapsed and is blocking air intake
Have you checked the water temp sensor?? maybe one of the wires broke off or the sensor **** its self and the engine is thinking its overheated and is shutting off cylinders. I know its a long shot but it sounds like youve tried everything else
Marcon i changed the pcm already and reflashed it.Same problem The weard part is at the track it was starting to pop out the exhaust when i left the line on the bottle.Same tuneup so i know that isn't it.The weard part i was running my best 60ft all season that day 1.26 but the car fell off in the big end? My last pass i had to get out of the throttle fast car was out off control and when o got on the throttle is when i noticed the problem.After all i have checked im thinking the reluctor ring might have slipped or something haven't checked it out yet.
02-13-2006, 12:05 PM
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Originally Posted by tuff
Okay couple more questions.Can you have a bad pcm without throwing any codes.