Timming

[RED1985]

I'm been lurking on the site for a few months and just recently signed up. I have a 1985 Chevy C10 Stepside with a 350 crate motor from the previose owner. The truck was running ruff so I checked the timing and it was at about 16 degrees. I adjusted it to 4 degrees and it ran very well. This was three weeks ago. Yesterday I went to take the truck out and it was running very ruff, almost like a misfire. I went to check the timming and it flashes a few times and goes blank and then will start back flashing again. I borrowed a friends light and get the same thing. Does anyone know what would cause this? I'm going to head out and get a plug wire tool so that I can pull each wire while it running to see if I have one missing.

I search the forums and could not find anything like this.

[willywoo28]

Couple of things I have found with me when I had this same issue:

**Rotor was shot, had corosion, and detonation marks on it.
**Cap was bad inside, loose terminal
**I also had a bad wire that had a pin-hole in it from burining the boot near the header
with the lights out you could see the spark jump through the hole.
**Finally the Coil had a lot of corrosion on the terminals in the cap. Cleaned them up

I would go through the baiscs though:
1) tune-up (plugs,wires,cap,rotor, coil) Make sure the gap is set.
2) Check the idle speed of your carb & air/fuel misture
3) Make sure you are checking the idle speed at the recommended idle speed..
4) Check your advance springs in the dizzy one of the weights could be loose and bushing shot...
5) check each spark plug wire with the light and motor running (not to set timing) but to see if it is a spark issue, It could also be the pickup inside the dizzy...

If the tuneup doesn't fix it, more than likely the pickup or the control module would be your culprit.

Good luck

Willy

[jhngardner367]

My '85 did the same thing,and it started eating dist.modules! Traced it back to a bad ECM,so I replaced the dist,with an earlier one,with vac adv/no computer,and removed the Ecm,from behind the glove box.Timing @4*btdc,500/drive. I picked up 3mpg!

[RED1985]

Guys thanks for the input, I gave it a tuneup a few weeks ago. Plugs, wires, rotor, cap, coil, fuel pump and new carb. I pulled and checked everything this afternoon and plug #1 had a chunk of crude on it. I cleaned the plug and she RUNS GREAT again. I guess I need to keep an eye on this one.