HELP 350 wont run under load!
Ok, my GMC Jimmy either HATES me or LOVES me too much, I have just about had it sold twice, and this time a guy drives almost 7 hours one way and she won't run right.
Here is a short version, 2 months ago, crank crank crank, not even trying to start (no spark) we replace distrib cap and rotor and all works till this last weekend.
Sunday, snowing like mad in NC, I go outside to crank it up, the guy is on the way to buy and crank crank crank, not even trying. I get some advice and decide to replace the ignition coil on top of my distrib cap. The Jimmy DOES crank after a while (wet electric issues from snow blowing into engine bay while replacing)
It finally starts, and I let it run/idle for 20+ minutes hoping all will dry out. I try to take it for a test drive and as soon as gas is given under load it stumbles and wants to die, let off and ok (ie idle no load)
I can race the engine in neutral/park, and is fine. (If I goose the gas real hard the carb/engine is backfiring some, carb makes a pistol shot sound and spits up a bit of gas vapor)
Based on some advice, I take it a mechanic who know more than me, but we are still having issues.
He has checked the timing and it is fine, he replaced the module (under the rotor) and checked the pickup coil which he said is ok.
You still cannot put a load on it, or it dies, I havent asked him about the backfire.
Some MISC info, the stupid exhaust manifold on drivers side IS cracked and is part of the backfire issue I am sure, you can hear the leak.
His next suggestion is he is going to swap the carb off his Blazer onto mine to see if it is the carb causing the issue.
If not, boy I am really scratching my head on this one, what do I look for? This has to be either electric or fuel right? Since I "had" an electric issue that I fixed and this problem started right after, doesnt that mean I still have an electric issue?