Misfire Under Load

[EM-0785]

Kevin,

I at one time had a leak coming from the upper front as well that was hard to find. Ended up that my coil, mounted sideways on the top front driver intake area was leaking oil. Inside the wire receptacle the screw that seals the oil in had come loose. If you're coil is in the same area perhaps that's it and perhaps explain the oil leak and related timing/spark issues?

Best of luck. Brent

[patrickt]

Don't do anything. First, have somebody trail behind you when you "burp" your oil plume. Have them tell you whether it comes out of one pipe, or two. If it's only coming out of one pipe, then your diagnostics will be different than if you're burping out of both pipes.

[Spyglass]

Originally Posted by patrickt

Don't do anything. First, have somebody trail behind you when you "burp" your oil plume. Have them tell you whether it comes out of one pipe, or two. If it's only coming out of one pipe, then your diagnostics will be different than if you're burping out of both pipes.

patrickt,

Good suggestion, I'll get my son to follow me.

Thanks
Kevin

[patrickt]

Originally Posted by Spyglass

patrickt,

Good suggestion, I'll get my son to follow me.

Thanks
Kevin

Make sure your son also looks for any smaller amounts of smoke that you might have missed. Also, in addition to hard acceleration, rev it up nicely and then back off the throttle so it decelerates in gear from a high rev with your foot off the gas. See if that produces smoke/backfires/massive explosions etc. Talk to your son on your cell phone as you're doing all of this so he knows exactly what you are doing when he sees the smoke. Being able to replicate a visual, or audible, problem on demand puts you about 75% on the road to a solution.

[Spyglass]

Originally Posted by patrickt

Make sure your son also looks for any smaller amounts of smoke that you might have missed. Also, in addition to hard acceleration, rev it up nicely and then back off the throttle so it decelerates in gear from a high rev with your foot off the gas. See if that produces smoke/backfires/massive explosions etc. Talk to your son on your cell phone as you're doing all of this so he knows exactly what you are doing when he sees the smoke. Being able to replicate a visual, or audible, problem on demand puts you about 75% on the road to a solution.

Will do.

I have noticed the odd minor pop /backfire on over-run from higher revs (say 3500), nothing major. Also last weekend the engine ran-on for a couple of seconds after I turned it off, it was quite hot at the time. It has not done this before.

Thanks
Kevin

[patrickt]

That engine should rev smoothly right past 5000. No pops, backfires, smoking, drinking, chasing women, or anything else. It should rev clean and even.

[86Sebring]

When I had similar issues and symptoms on my small block, a good cleaning and carb rebuild fixed the stumbling and hesitation.
If the smoke coming out of the exhaust is blue, that would indicate burning oil, black smoke = rich condition
Just a thought

[Spyglass]

Originally Posted by 86Sebring

When I had similar issues and symptoms on my small block, a good cleaning and carb rebuild fixed the stumbling and hesitation.
If the smoke coming out of the exhaust is blue, that would indicate burning oil, black smoke = rich condition
Just a thought

Until I experienced the burp of blue smoke at full throttle, I was suspecting a carb issue -blocked jet, float height, etc., basically insufficient fuel flow to support higher power outputs. But the burp of blue smoke I experience last weekend made me think again. Although I could have multiple issues.....

Thanks for your input.
Kevin

[Spyglass]

Originally Posted by EM-0785

Kevin,

I at one time had a leak coming from the upper front as well that was hard to find. Ended up that my coil, mounted sideways on the top front driver intake area was leaking oil. Inside the wire receptacle the screw that seals the oil in had come loose. If you're coil is in the same area perhaps that's it and perhaps explain the oil leak and related timing/spark issues?

Best of luck. Brent

Brent,

Good suggestion but there's too much oil on my garage floor for it to be coming from the coil, plus there's no oil on the inlet manifold where the coil is mounted.

Thanks for your input.
Kevin