Or maybe it isn't closed loop? It runs for about 7-10 minutes and then cuts out when I give it gas and dies when I let off.


"IF" it is closed loop and maybe my O2's, should it start up and run right if I unplug them??? Or not run at all?


If that isn't the problem, I'll check the coil and ICM.

 

Should the motor reach closed loop within that time frame???

 

Closed loop starts after approximately 2 minutes. How does your car run for the first 7 minutes?

 

Runs fine. Today it was a little cooler here than it has been and I drove all the way to work and it never messed up....about 10 minutes.

So, I'm thinking coil/ICM has a heat issue.

 

I spaced the coil/ICM out about 3/8" and then drove it.

IT COMPLETELY DIED!!!!!!!!!!! Drove it for about 10-12 minutes. It would usually crank back up, but not this time. Had to get it towed home!

 

To see if it was getting spark, I unplugged the coil-to-opti wire and cranked the car over. It was firing so I unplugged one of the spark plug wires and it was firing as well.

The spark was sorta orange though. Shouldn't it be blue(ish)???

 

Just remembered that I have another LT1 car that I can "borrow" parts from!!

This should keep unneccesary spending to a minimum.

 

OK....I ended up putting new plugs in it, they were fouled pretty BAD!!

Then I put the "borrowed" stuff on and fired it up to make sure it worked. It did.

Then I put the original back on and fired it up. It ran about 20-25 minutes then died. I put the borrowed stuff back on and fired it up again. It ran about 5-10 minutes and died. WTF??!!

I pull a plug wire and it's firing. Since I fouled the plugs pretty bad last night, I started pulling the injector fuses so it won't flood out while cranking. Well, the damn thing tries to START with the fuses out!!!!!??????

So that makes me think it's "ALL OF A SUDDEN" dumping TOO much fuel. I also unplugged the O2's after this and nothing changed.



VERY weird how it will hit and run (for a couple seconds) with the injector fuses out!!

 

Seems like I'm talking to myself here?!!



Just scanned it and found NO codes. Which is wierd, because the SES light is almost ALWAYS on?!

 

Marshall, a few of things come to mind, check the fuel pressure, and the ability to hold that pressure after you stop cranking or stop the engine. The other thing did you check the O2 sensors? Also try placing a noid light on one injector wire to see if it is being powered when cranking over the not running engine (fuse installed, of course).

 

I just went and got a fuel gauge and when I turn the key it shoots to around 47 then falls to 41 and holds for a while. It leaks around the valve/gauge connection but not bad. Takes about 3-4 minutes to fall to about 37-38. That seems to be good, right?


The O2's are factory!! 266K miles on them. I'm sure they need replace, but would they cause this problem? I unhooked them and it made no change to my problem.

I'll try the noid light, but it seems to be dumping ALOT of fuel. I can smell it pretty strong after a few times trying to start it. And like I said up above, with the fuses pulled, it will actually run about 3-5 seconds from all the gas in the cylinders!

 

Try getting some new 02 sensors, my car did this while I was running open LT's. Because the 02's were sending the wrong air:fuel. Put my y-pipe and exhaust back on and the car ran perfect.

 

Ok, I messed with it some more. When running fuel pressure is 40 psi and with the vacuum line off it is 50.


I have noticed that when right before it wants to die, the idle will raise about 200-300 rpms. And then if I BARELY touch the gas it stalls out!

 

Could the TPS have anything to do with it?

 

So when the motor stalls did you immediately check for spark or wait a while?