ECM issue? I need advice
10-26-2009, 12:15 PM
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ECM issue? I need advice I have had this issue for about a year now...
my car runs fine under low throttle. Once i give it about half throttle it falls on its face and will not hardly accelerate. Under WOT it will not even pass ~3500rpm instead it will scream and bounce like its hitting the rev limiter or horribly misfiring.
Ive had it on an OBDII scanner a couple times and it shows nothing wrong even under load.
A very experienced ASE mechanic friend of mine drove it and told me it's the transmission because it won't shift under WOT... This makes no sense to me because at 3500rpm its not even getting near it's shift point and it shifts flawlessly at any other point along with the half throttle issue. Also it was rebuilt by a very reputable shop just 30k ago.
I described the problem to some1 wantin 2 race me with his LT1 car and told me he had the same issue which turned out to be his computer. Which is what I was already thinking the issue is.
Where should i go to find out if it is the ecm? If it's bad i want to replace it myself to save alot of money.
I know someone locally that tunes for just about every LS1 owner I know. should he be able to tell me assuming he knows what he's doing?
my car runs fine under low throttle. Once i give it about half throttle it falls on its face and will not hardly accelerate. Under WOT it will not even pass ~3500rpm instead it will scream and bounce like its hitting the rev limiter or horribly misfiring.
Ive had it on an OBDII scanner a couple times and it shows nothing wrong even under load.
A very experienced ASE mechanic friend of mine drove it and told me it's the transmission because it won't shift under WOT... This makes no sense to me because at 3500rpm its not even getting near it's shift point and it shifts flawlessly at any other point along with the half throttle issue. Also it was rebuilt by a very reputable shop just 30k ago.
I described the problem to some1 wantin 2 race me with his LT1 car and told me he had the same issue which turned out to be his computer. Which is what I was already thinking the issue is.
Where should i go to find out if it is the ecm? If it's bad i want to replace it myself to save alot of money.
I know someone locally that tunes for just about every LS1 owner I know. should he be able to tell me assuming he knows what he's doing?
10-26-2009, 12:31 PM
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If he's got HP tuners or something similar he should be able to monitor the computer and see if its doing something screwy. It may be that your program has gotten corrupted and needs to be reflashed. If the computer itself was bad then the car shouldn't even run.
10-29-2009, 06:52 PM
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With the engine idling, firmly tap the control module under the hood. If the engine stumbles, then your computer is not functioning properly. Check all of your connections on the pcm.
Guy above me, that's a sexy ss.
Guy above me, that's a sexy ss.
10-31-2009, 08:23 PM
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thanks for the replies and tips.
i had cleaned my maf wires with electrical cleaner but it made absolutely no difference. also wouldn't it show on a scanner if it was bad? or can it sneak by unnoticed.. i thought the oil from my k&n could cause an issue
i had cleaned my maf wires with electrical cleaner but it made absolutely no difference. also wouldn't it show on a scanner if it was bad? or can it sneak by unnoticed.. i thought the oil from my k&n could cause an issue
11-01-2009, 01:52 AM
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3500rpm... I had the fuel pump hose inside the tank crack and some of the fuel from the pump would come out back into the tank... so not all of it made it to the engine. The whole time the car ran really louzy and wouldn't go over 3500rpm
