Hi, I'm new here.
I posted this info on other Jeep boards, but I haven't had any luck solving it yet. I was hoping that maybe someone here would be able to help. Thanks for giving it a shot.
I swapped in a 4.3L vortec with the 4L60E from a '94 Chevy Astro van into my CJ-7 last year. When the air temp is above about 90 degrees (won't be happening anytime in the near future
) the engine would just stop running. No sputtering, coughing, or loss of power prior to dying. After about 20 to 30 minutes of letting it cool off, it would restart and run fine for about 5 to 10 minutes, then die again.
No check engine light before or after it died, and no codes were stored. It would crank over, but wouldn't fire. I found that if I poured cold water over the dist. it would start alot sooner then if I just waited, but it would also die again sooner.
I swapped the coil and the dist. ignition module (I was in the middle of Montana at the time), but the problem is still occuring.
I haven't had any problems when the air temp is cooler. When the engine does die, the engine temp gauge doesn't show any increase over normal levels.
Some additional info that I posted later.
I checked the fuel pressure - it was good at about 58 psi. This is a CPI fuel injection setup. The spark was a very weak yellow spark when it had this problem.
I had someone tell me that it could be the weather-pak connectors. I guess that the theory is that because the connectors are water tight, that they are getting hot and separating. That is a tough one for me to believe it might be a possible cause. Have you guys ever heard anything like that?
I started trying the dist. parts due to the way it would start faster when I cooled it off with cold water. This engine has a little over 30,000 miles on it. It runs like a top the rest of the time.
This problem only occurs on the black top. When I'm on the trail, I haven't had any problems even when the air temp was over 100 degrees. Maybe the hot air isn't able to exscape fast enough when I'm at speed, and I'm over heating a component. My experience with electronics would lead me to believe that once overheated, it shouldn't work again.
Just to let you know, the fuel pump has about 4000 miles on it and is external style with the fuel filter upstream of the pump. I haven't had any problems with vapor lock, and when it dies, it doesn't give any advance warning by loss of power or sputtering.
I would have thought that a problem like this would have be sensed by the ECM, but no codes afterwards and no check engine light at all.
I appreciate you guys giving me input on this. I don't just want to start throwing parts at it, so its nice to hear what someone else thinks.
Any ideas? Thanks in advance.