whats going on!

[rkarrjr]

I have a problem that is baffling. One day I drive the van with no problems. Next day or whenever out of the blue,it starts running like a bucking bronc. Missing,and spitting,and STINK.Come to a stop and just about stalls. Not noticed to much at road speeds. Although it is probably doing then also. I have tried the gas additives,like fuel line cleaner or injector cleaner. No luck.About 2 years ago it did this for my wife,I went to tow her home,and it started and ran fine. Then again about a year ago. Now it is about two or three times a week. I am scared to drive it anywhere. Any help would be appreciated. Here are the details. 1994 GMC Safari 4.3 V6 244,000 miles. A very good van,and would buy another. Just having troubles right now. Thanks to all.

[LTJGWorth]

Maybe a new alternator. Mine did something simialiar and would start sometimes on the old alternator but if i drove it somewhere or let it sit while running it would start to act up and quit.

[gaslady]

sounds real similar to what my 93 with 125000 miles did. the original thought was the fuel pump or blocked catalytic converter but turned out to be just a fuel filter in the gas tank. cost about $110 to fix at our local shop. dropping the gas tank was not a job I wanted to do.it did the same as yours sounds though including the frequency of happenings. usually was worst when temps were real hot or changed drastically for whatever reason.

[GMCTech]

Sounds like your EGR valve may be stuck open.

Check there first.