Camaro ECM Issue - Starting Issue
#1
Camaro ECM Issue - Starting Issue
My 1997 had a bad ECM module and had no starting problems whatsoever beforehand. Since installing my ECM the car runs great except for one issue, it starts on the second attempt to crank almost everytime. I had a local mechanic swear it was fuel pump and filter but that did not fix the problem and was a waste of money. Anyway to do a relearn procedure or any advice would be helpful...thanks
#2
how long have you had the new ecm in. how many runs? it does take a few to relearn. may need to clean and reset your iac valve. also may want to look at your minimum idle setting. idle with iac closed should be in the 400-500rpm range. if you have a scanner i think you can do it. you need to put the system into diagnostic mode which will close the iac. then unplug the iac and start engine. may have to give it some throttle to start. then using the throttle body idle screw set the idle. shut it off and plug the iac back in.
#4
how long have you had the new ecm in. how many runs? it does take a few to relearn. may need to clean and reset your iac valve. also may want to look at your minimum idle setting. idle with iac closed should be in the 400-500rpm range. if you have a scanner i think you can do it. you need to put the system into diagnostic mode which will close the iac. then unplug the iac and start engine. may have to give it some throttle to start. then using the throttle body idle screw set the idle. shut it off and plug the iac back in.
#5
I will look for trouble codes also....I am waiting for the "check engine" light to reappear because I cleared it when I removed battery cable suring ignition switch install....thanks!!
#6
Join Date: Nov 2007
Location: Eastern PA,
Posts: 10,354
When a EFI car will not start your are missing something. Normally it is one of 3 things. Spark, fuel pressure or the signal to the injector. Step one is to figure out which is not there while you are trying to start the car the first time.
The reason your mechanic thought it was the fuel pump is because it is a common issue. The fuel pump has a check valve that keeps the fuel from running back into the tank. A empty fuel line can take 5-10 seconds to fill up. The reason he did the fuel filter is because it was required on a fuel pump replacement or you void the fuel pump warranty. When we see such a common problem we some times jump to conclusions. A single mechanic could have easily seen this same issue in 20-30 car and it was always fixed by the same thing.
I would still suspect a defective valve in the new fuel pump. It is easy to test. First thing in the morning turn the key to the on position without trying to start the car for 5 seconds, then turn it off. Repeat that a second time then try to start it. If it starts it is most likely a defect check valve in you new pump. (yes I have seen that before in a 4th gen with a brand new pump) In fact I have one in my driveway right now that is on its third pump, I just got use to turning the key for 5 second before I start it. I did that for 3 years.
Also if it does start I would confirm the finding with a fuel pressure test. If you try to start it cold the car should have low to no fuel pressure then within a second or two of the fuel pressure rising the car should start.
The reason your mechanic thought it was the fuel pump is because it is a common issue. The fuel pump has a check valve that keeps the fuel from running back into the tank. A empty fuel line can take 5-10 seconds to fill up. The reason he did the fuel filter is because it was required on a fuel pump replacement or you void the fuel pump warranty. When we see such a common problem we some times jump to conclusions. A single mechanic could have easily seen this same issue in 20-30 car and it was always fixed by the same thing.
I would still suspect a defective valve in the new fuel pump. It is easy to test. First thing in the morning turn the key to the on position without trying to start the car for 5 seconds, then turn it off. Repeat that a second time then try to start it. If it starts it is most likely a defect check valve in you new pump. (yes I have seen that before in a 4th gen with a brand new pump) In fact I have one in my driveway right now that is on its third pump, I just got use to turning the key for 5 second before I start it. I did that for 3 years.
Also if it does start I would confirm the finding with a fuel pressure test. If you try to start it cold the car should have low to no fuel pressure then within a second or two of the fuel pressure rising the car should start.
Last edited by Gorn; 01-01-2016 at 11:38 AM.
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