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Discussion Starter · #1 ·
Hey all. I have a 1993 Firebird Trans Am LT1 with a six-speed manual transmission. The engine has headers and a cold air intake. Recently I installed the EGR system that was deleted by the previous owner. Immediately after this, I got better gas mileage but started overheating. I replaced my coolant temp sensor but that didn't help. I discovered that if I unplugged the coolant sensor, the fan would run at all times and keep my temperature at 180.

I ran like this for a full week, having no problems starting or running. After about six days of daily driving, I started my car to leave school, went to AutoZone, started it again, then went to Advance Auto, and started it again. On this third time starting, my RPMs started to flutter up and down on their own. Even while I drove, they would still flutter. I finally got home after the engine stalled on the road a few times and tried to draw a code. I had a code for the unplugged sensor but that had been there for a week. The only new code to pop up was code 22 for a TPS sensor. I replaced that, no luck. I replaced my Idle Air Control Valve and electrical connector. Still, I could start the car, but it would flutter and die in a matter of seconds.
Fuel pressure is where it should be. The injectors have not been replaced but I pulled the fuel rail and cranked the car, all had fuel coming out, so I assume they're good.
I've already replaced the spark plugs and wires. I've sprayed everywhere for a vacuum leak, but no dice.
At this point, I have no clue what to do. I can turn over the car, it will catch, rev up, and then die. New battery didn't help. Any advice would be greatly appreciated.
 

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Discussion Starter · #2 ·
To all reading:
I recently replaced the injectors. No luck, same result.
Then I started messing around with the wires on the driver's side going into the ignition coil. This caused all spark to be lost and then I couldn't start the car at all.
Moved around the wires again and it all came back. Sometimes after I move the wires around, the car will stay around regular idle rpm, but not actually be idling. And anytime I touch the gas, it starts to flutter again. Anytime I touch the wires, it flutters.
Decided to replace the ignition coil because it was cheap and the old one was cruddy. Still the same result. I know that this is a wiring issue, but I don't know the problem.
I've checked and cleaned the grounds. No dice. So it leads me to believe that there is a broken wire hidden somewhere under the rubber insulators and I just can't see.
There is also a little cube/box that wires into the ignition coil. A white wire comes from the ECM, goes into the box, and comes out with another white wire and a ground wire. The other white wire goes to the ignition coil, not on the tach side. I've noticed that when I used to run the car and was fooling around under the hood while it ran, whenever I moved this box around it shut the car off. Any clue what this thing is or if it may be the problem?
Again, thanks in advance.
 

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Check the wires and connection for the ICM. I just had a high rpm miss, and when inspecting, I found that one of the wires caused the car to straight die, and run like crap when I did get it restarted. Replacing the ICM connector cured the issue.
 

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Discussion Starter · #4 ·
Check the wires and connection for the ICM. I just had a high rpm miss, and when inspecting, I found that one of the wires caused the car to straight die, and run like crap when I did get it restarted. Replacing the ICM connector cured the issue.
I have noticed that hitting the tach filter when the car used to run good would cause it to shut off. However, it would start right back up just fine after that. Now it seems that whenever I am messing with that loom it will give me a different result: not start at all, tach doesn't move/ starts then stalls immediately/ starts and flutters/ or starts and hangs around idle but flutters once I hit the gas.
I just replaced the distributor and I am still having the same issue. I will try the ICM connector and/or the ICM fix to see if that resolves the issue.
 
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