Stumbling

[Ackattack]

So I've been using my 69 GMC to run to the parts store / home depot / what ever occasionally.

Generally speaking, it starts up pretty easily and runs good for awhile.

After awhile after it's gotten a chance to heat up, when you pull up to a stop sign or whatever, when you start going again, it really stumbles and doesn't want to go for a few seconds. Once it gets going though it's fine.

It will do this when the coolant is hot, but if you let it cool for about a half hour, and start it back up, the coolant is cool, but it will still do it.

Before I start throwing parts at it, I wanted to see if anyone had any ideas on what to check. I'm thinking it's the ignition module and/or coil (it has an HEI dist.). The engine is your basic old 350 with a Edelbrock carb (manual choke) and a 4 speed manual.

I checked the vacuum line from the carb to the distributor, and the distributor is advancing the timing as it should with the vacuum.

[Leviticus]

Not sure if you are running an Edelbrock carb, but if you are, my choke likes to get stuck just a tad closed and I get these exact same symptoms. I have to pop the hood and manually open it up all the way cause the cable doesn't have enough force to push it back open.

Been meaning to fix it.......one of these days lol.

Edit: Guess I should read the post, you do have a edelbrock. Try what I mentioned above.

[Ackattack]

that could be it, I'll check it

[69GMCLonghorn]

Well, you'll probably get a 1000 responses with all kinds of good advise. Just throw parts at it. Eventually it will go away, AND you'll have a whole bunch of new stuff on the motor!

[Leviticus]

Originally Posted by 69GMCLonghorn

Well, you'll probably get a 1000 responses with all kinds of good advise. Just throw parts at it. Eventually it will go away, AND you'll have a whole bunch of new stuff on the motor!

You forgot the most important part! Throw a bunch of "billet and chrome" parts at it, and tell the wife you needed them to get it back on the road

[epashhans]

This probably isn't your problem, but I had an old truck that started doing that...I finally figured out that it was the fuel line. I had it doing a bit to much of an angle and when it started getting hot the hose couldn't hold its shape and would kink...shutting the fuel amost completely off. I just took the time to re-route it correctly and never had another problem.

[tim21391]

are the points shot or are you running hei

[Leviticus]

He is running HEI

[tim21391]

could the cap be shot?

[Leviticus]

Ack,

You get your truck fixed up?

[292farmer]

i had 1986 k20 chevy with a edelbrock carb on my 350v8 and i reused the old line and the truck did the same thing, turned out the fuel line was pushed against the motor by the new fuel inlet location on the carb and was causing vapor lock as the fuel line was heated by the block lol so check your fuel lines proximity to block and anything hot.

[D-Rat]

might be a good place to ask how an electric choke on a holley works. I'm having similar issues that just started up. The truck seems to be running rich when it's warmed up - symptoms of maybe a sticking choke or a vacuum leak. I'm also getting the occasional backfire on the left cylinder bank.

[Ackattack]

Update:

The choke is operating fine.
I replaced the vacuum line from the carb to the distributor (seemed like it was colapsing with vacuum).

I replaced the ignition module, rotor, cap, and coil. I figured at least it would drive better.

I took it for a dump run, and not it's worse!!! I pulled up to a stop sign and it would die. It did this over and over at each stop sign. I could also feel it misfiring occasionally, and backfiring while decelerating (didn't do either of those before). Then today I went out to move it, and I couldn't even get the stupid thing to start.

[72swb_327stroker_?]

sounds like it could be timing chain stretch?

when was the last time you checked the timing?