Idling rough after pulling a stump out

[RicksTrucks]

69 SWB with 350 crate, 4 barrel Edelbrock carb.

Was using the truck to pull out a small tree stump. The tractor wasn't running and the wife wanted it out.

Pulled a few times and a couple of the times it killed the engine when I got to the end of the chain. The time before the stump actually came out, when I restarted it, it ran rough. Finished the job and the checked it out.

Idles a little rough in neutral. Put it in drive and it is worse, but seems to drive okay.

I check the distributor (HEI) to make sure it was tight and didn't move and it seemed okay. Any ideas?

[68gmsee]

You may have knocked a vacuum hose loose. I'd start by checking all the hoses vacuum hoses including the vacuum modulator.

Another possibility, is that you may have dislodged some sediment from the gas tank an possibly got some gook in the carb.

[RicksTrucks]

Originally Posted by 68gmsee

You may have knocked a vacuum hose loose. I'd start by checking all the hoses vacuum hoses including the vacuum modulator.

Another possibility, is that you may have dislodged some sediment from the gas tank an possibly got some gook in the carb.

Thanks. Did forgot to mention that I did check all of the vacuum hoses. Have had that happen before. I do have a clear inline filter and did notice on my way back from Arkansas Friday that there wasn't much fuel in the canister, just at the bottom - where I have seen it full in the past. In fact I think it was full when I was checking the vacuum hoses before my trip.

I will look at the fuel system some more.

[matthufham]

if you have rubber fuel lines, one could of kinked. or check the vacuum line that goes to the tranny, if you were off road, then something could of snagged it?

[Longhorn Man]

shook a plug wire off maybe?

[RicksTrucks]

Originally Posted by Longhorn Man

shook a plug wire off maybe?

Plugs wires good. In fact I changed the plugs thinking maybe I had fouled one. So as far as I can tell plugs are good, wires are good, all vacuum lines check out. May pursue the fuel angle next. Verify that the filter is not filling up, which may indicate clogged fuel line somewheres. Got several extra tanks in case I got stuff in mine.

Thanks and keep the ideas coming.

[matthufham]

distributor cap didn't hit the firewall? so it's good with a good rotor? maybe the distributor drive gear is getting worn. i wouldn't assume valvetrain issues (timing chain, valves, lifters, pushrods) since it's a newer gm crate that's been checked.

i have a edelbrock 1406 and i had to raise the float levels, clean my jets, and upgrade the needle and seats to the off road ones to get mine running right, don't know why. it's real easy to open that thing up now though. check the choke to see that it's open a little until warm, then fully open. assuming electric choke.

[ChevLoRay]

I have one of the glass filters on mine (I know, I know) and when it wasn't filling up, I thought I'd check the hoses. Good thing....they were toast, which is to say my truck could have been if a hose had leaked gasoline onto a hot header. After changing the hoses, the filter filled up and stayed full, and the truck started much more easily.

[RicksTrucks]

I checked the fuel filter this morning and it was full when I started it up and still ran rough. The fuel hoses should be good - replaced the last bad one a few months ago. But thinking about going through the whole fuel system this weekend.

[Wookiee]

Sounds like what happened to me a couple weeks ago when I Pulled some rocker studs. Tached it up a bit much on the interstate, but I know you can do the same thing trying to yank a stump. Ran the same way. Idled kinda rough, then got worse in gear. Hoped it was something simple like a vaccum leak or fouled plug or something, but all that checked fine. Ran a compression test and found nothing on 1&3. Still trying to find time to re-stud the heads. Hope it's something simple, but I can see where it could be something less so.

[RicksTrucks]

Originally Posted by Wookiee

Sounds like what happened to me a couple weeks ago when I Pulled some rocker studs. Tached it up a bit much on the interstate, but I know you can do the same thing trying to yank a stump. Ran the same way. Idled kinda rough, then got worse in gear. Hoped it was something simple like a vaccum leak or fouled plug or something, but all that checked fine. Ran a compression test and found nothing on 1&3. Still trying to find time to re-stud the heads. Hope it's something simple, but I can see where it could be something less so.

What was the cause of no compression? Not familiarwith re-studding heads.

[Huck]

Start at the basic compression test then go from there. You could have loosened a rocker stud in the head, popped off the upper tip on a valve shaft, etc. There are lots of things that can cause a mis. Use a spark tester for each cylinder, recheck timing--hook up a vacuum gauge to see what it reads--look at GMC Pauls tech tips on vac gauge tune up.
A mis rough running engine at idle that ran fine before ---i would suspect ignition (plug, plug wire, cap, vac) before I would supect fuel. But that said, I have been surprized many times too!!

[BLACK AND BLUE 67-72]

It's possible that you could have a broken valve spring causing your miss also. My truck did this after I passed a friend of mine at high speed....

[Wookiee]

The rocker studs pulled out of the head, causing the valves to no longer open. By "re-studding", I meant I decided to replace all my studs with the screw in type. I agree with Huck though. Go through and check the easy stuff first. More than likely that's where the problem is, but if not check compression and you've got an idea of what else to look for.

[rstewart09]

My have broken a motor mount and engine is just bouncing around in there.