the B350 motor has suddenly developed a really bad stumble, but only going uphill (wierd, eh?). almost feels like its out of gas, or that its running on 4 cylinders. it really stumbles hard. i'm not sure if its the quality of the local gas, but I noticed some pinging during the last tankful of gas. Wondering if anybody has info on how to diagnose a bad HEI module.
Have you refueled lately...... did it start to act up soon after getting gas? I have had many cars that got bad fuel or water in the gas and as soon as the car would hit an incline, the water would roll to the rear lowest part of the tank (at the pick up) and the car would run like crap. Got a fuel pressure guage? You can also pull the line from the pump and drain some gas into a glass jar....then leave it sit all night. In the morning, check for sediment in the bottom of the jar....... water would be at the bottom. I am not saying that it's not the HEI.... just doing the easy stuff first. Mike
I don't think it has anything to do with the HEI or module. When they fail, the car won't run at all. Sounds like a fuel problem to me. A fuel pump on it's way out will do this. Could be an altered float level in the carb also.
seems like we are on the right path, I filled it up at new station I'd never been to before ("least expensive" gas I could find...) and it started right after that. hope I didn't get what I paid for. Also had the top of the carb off to adjust the choke system, the choke rod had fallen off so I had to pull the top. Nver rechecked the float level. But that was 4-5 days ago, and it was running soooo good after that. It seemed reasonable that if the HEI failed, that it would fail more dramaticaly.
not nesseserily.. -I once had a module that made the engine go ape-**** when it got warm / or under acceleration.. -made the engine go Bang so loud that the cops stopped me at the freeway, and thought I had ran into something, and/or shot a gun... -no joke man.. -some other driver even stopped also.. -they were really baffled.. -but fortunately I only had to replace the HEI-module (stock) ,-and it ran fine again..
