LT1 Help needed with stalling
Thread Starter
Teching In
Joined: Oct 2019
Posts: 18
Likes: 0
From: Ohio
LT1 Help needed with stalling A little back story. About a month ago I bought a 1996 Firebird with the LT1 and M6 trans. the vehicle was a no start and the previous owner believed the optispark failed and tore it apart. Once I bought it I purchased a new Opti, module and coil from O'Reilly's and put the car together and still did not start. The car has been modified to OBD1 the engine was rebuilt with a94 timing cover, LE cam, ported heads, headers and tuned.
Once I was able to acquire a scan tool I found I had no data further investigation revealed the knock module cover was missing and the PCM actually had standing water in it, I found several corroded wires and replaced the terminals A2,A18 on the Red connector, B15, B30 and B31 on the black connector and found no others corroded so far. Once I replaced the terminals the car started right up one on the original PCM after putting the PCM in a food dehydrator for three days but was setting a code 42. I replaced the O'Reilly's module with the one that was on it when I got the car and code 42 went away; however, what I have found once the car gets hot once in a while it stops responding, IE just shuts off and then comes right back on after a few seconds just like a switch was flipped off and back on. only once did the car completely stop running and not come right back on which was during the logged run.
I bought an aldl cable and used EEhack to create a log file. I was a master tech but switched to IT close to two decades ago and have not messed with data streams until this car which was supposed to be my wifes birthday present. I noticed in the log that when the stalls happen the log just seems to stop, no errors that say lost communication, is this normal for EEHack? I have been unable to see anything that stands out in the log that says ya the PCM is cutting out. Today I did the wiggle test quite firmly and had nothing happen, did the tap test on the PCM and the MAF , jiggled the ignition switch wiring and also had no results. Right now I am at a loss and having a hard time figuring this out and do not want to just throw parts at it.
Also I should mention that I was able to pull the tune off the water logged PCM which had "LT1 Dave" wrote in sharpie on it, I used TunerCat to load the tune on the other PCM but also do not know if the knock sensor was changed to an OBD1 one or not as I do see some knock but cannot remember from my past days if that is normal or not. Also I used TunerCat to correct the speedo for the 3.90:1 rear gear and turn off VATS but that is all I did.
Does anyone have any advice or able to see anything from the log that stands out. The zip file is the log file.
Once I was able to acquire a scan tool I found I had no data further investigation revealed the knock module cover was missing and the PCM actually had standing water in it, I found several corroded wires and replaced the terminals A2,A18 on the Red connector, B15, B30 and B31 on the black connector and found no others corroded so far. Once I replaced the terminals the car started right up one on the original PCM after putting the PCM in a food dehydrator for three days but was setting a code 42. I replaced the O'Reilly's module with the one that was on it when I got the car and code 42 went away; however, what I have found once the car gets hot once in a while it stops responding, IE just shuts off and then comes right back on after a few seconds just like a switch was flipped off and back on. only once did the car completely stop running and not come right back on which was during the logged run.
I bought an aldl cable and used EEhack to create a log file. I was a master tech but switched to IT close to two decades ago and have not messed with data streams until this car which was supposed to be my wifes birthday present. I noticed in the log that when the stalls happen the log just seems to stop, no errors that say lost communication, is this normal for EEHack? I have been unable to see anything that stands out in the log that says ya the PCM is cutting out. Today I did the wiggle test quite firmly and had nothing happen, did the tap test on the PCM and the MAF , jiggled the ignition switch wiring and also had no results. Right now I am at a loss and having a hard time figuring this out and do not want to just throw parts at it.
Also I should mention that I was able to pull the tune off the water logged PCM which had "LT1 Dave" wrote in sharpie on it, I used TunerCat to load the tune on the other PCM but also do not know if the knock sensor was changed to an OBD1 one or not as I do see some knock but cannot remember from my past days if that is normal or not. Also I used TunerCat to correct the speedo for the 3.90:1 rear gear and turn off VATS but that is all I did.
Does anyone have any advice or able to see anything from the log that stands out. The zip file is the log file.
