ignition problem?
Thread Starter
Racer
Joined: Jul 2004
Posts: 450
Likes: 0
From: Fredericksburg VA
ignition problem?
I'm back at school now, so I don't have the car with me, but I'm planning to go back home in a couple weeks so I figured I'd go ahead and try to get some info for when I get there. Headers are on and the gas leak is fixed but now I'm having what appears to be an ignition problem...sitting at idle its fine, and when I had it up on jack stands it didn't appear to have any problems, but when I'm driving down the street the car kicks a lot almost like a cylinder isn't firing at all. What are some possible reasons for this? I don't think any of the spark plugs are broken, and I don't think any of the plugs are melted, but is it possible that they just don't look broken or melted to me and actually are? Thanks
Steven
Steven
Tech Contributor
Joined: Aug 1999
Posts: 14,370
Likes: 6,364
From: At my Bar drinking and wrenching in Lafayette Colorado
Kicking, bucking and jerking while at light throttle cruise is an indication of one of two conditions:
1. Timing over-advanced
2. Lean condition
If you just installed headers and a free-flowing exhaust with a stock calibrated carb, the new system will lean you out. You need to re-jet to compensate for the headers.
But do check your timing and make sure you're running 36 total and that your vacuum advance unit is not pulling in any more than 16 degrees. This will produce 52 degrees total combined timing max. If you have it set up to produce more than 54, you will get the problem you describe.
1. Timing over-advanced
2. Lean condition
If you just installed headers and a free-flowing exhaust with a stock calibrated carb, the new system will lean you out. You need to re-jet to compensate for the headers.
But do check your timing and make sure you're running 36 total and that your vacuum advance unit is not pulling in any more than 16 degrees. This will produce 52 degrees total combined timing max. If you have it set up to produce more than 54, you will get the problem you describe.
