Timing? Cam? Carb? '86 K10 bogs like nobody's bidness.

[Don Gwinn]

Just so everyone knows, I ran a search and came up with nothing, which is the only reason I'm posting a new thread.

I have a 1986 K10 with a 305 and a Quadrajet. I got the truck from my dad, who drove it for many years until he got a '95 with a diesel. Anyway, the thing bogs horribly, and I've done all the simple stuff I know to do--air filter, fuel filter, clean the carb, etc. My next step was going to be to attempt to rebuild the Q-jet and see if I can tune it better.

It bogs from a stop unless you accelerate hard, which seems to help. Recently, I drove it to work 30 miles away and that night (which was very cold) it died twice on the highway on my way home. Both times I was able to restart it, but the second time it stopped me, it took at least ten tries to pull back onto the road. The truck would start, it would run in gear, but when I touched the accelerator it died again. When that stopped happening, the truck was back to normal, although it still bogged.

However, I spoke to dad and he says he had the carb rebuilt professionally a few years ago. This would be, probably, 7-8 years back. Could it really be due for another rebuild? He thinks it's probably a timing issue, possibly to do with the distributor. I believe that's HEI on this model, but I don't really understand timing or how it works. I want to learn, though.

How would I go about diagnosing a timing problem? On my old Ford, I would just turn the distributor slightly to advance or retard and see what happened, but that wasn't electronic.

1. My search did turn up a statement by someone that "305's are notorious for bad cams." Is there a way to diagnose this problem without simply replacing the cam to see what happens? Come to think of it, the idle is a bit "lopey" though not really rough, and as far as I know the cam is stock.

2. Could timing chain stretch cause this problem? If so, can I diagnose that without tearing the engine down to the timing chain?

3. What about the distributor? This truck did have an ignition module fail once before, when dad owned it, but that cause random shutdowns rather than bogging down on acceleration or bad mileage.

4. What would you do first? Obviously I want to start with the simplest, cheapest thing likely to fix the problem and work up from there.

It's time to start hauling mulch, dirt and lumber again as I work on my ancient money pit of a house, so I need to get this truck running right. Thanks!