And more mechanical problems!!

[71GeneralMotorsCorp]

Okay guys, got my truck back from the shop and it now runs!! turned out to be a bad distributor. Anyways, stating that it runs, it does not run well.. at all. IT DOES HAVE AN HEI DISTRIBUTOR.. It has no power at all, it backfires (from the carb and exhaust) spits, and stalls just from driving in normal conditions (0-55). and here's the kicker, the lights pulse. Interior and exterior. the voltmeter jumps from 14 all the way to 18+ volts while driving. Please help me figure out why my truck is acting up! Thanks in advance!

[volksworld]

well,start with a voltage regulator....that's an easy install....you took it to a shop and that's how they gave it back? no mention of what else they thought might be wrong?....or was this a "get my truck to run I have absolutely no money" deal?....what diagnostics did they do,so you'll know whats ok? did they put in a new HEI or a junk one...is this something you bought not running,or a driver that just started acting up? my first guess would be carb or bad timing chain but a lot more info would be needed

[68gmsee]

As mentioned above need more specifics. Engine, mileage, any work done to the engine itself.

Lots of things can cause the problems mentioned. Here's a few (do one thing at a time with the easiest first).

Check:
-timing
-vacuum leaks - vacuum advance?
-install ground straps even if you don't suspect them -engine to cab, cab to frame, radiator support to frame, and maybe another engine to frame one.
-check battery cable at the post connection for internal corrosion.
-alternator could be defective
-double check firing order. They may have screwed that up and not hard to do.