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What’s it mean when engine runs with cmp sensor 180 out

Posted: May 18th, 2021, 7:19 am
by b.rudy
Hey guys, I haven’t posted much but I’ve been ghosting for a while. Just got my 4.6 stroker running and I’ve got a glowing header issue. I have done lengthy diagnosis of the issue and I am still having issues. However one thing I did notice is that irregardless of whether the crankshaft is at TDC compression or exhaust stroke when I install the cam position sensor timed with a toothpick the engine will run regardless..? I still need to tune it (using HP Tuners) but why would it run decently. Even if 180° out?
I have borrowed a friends snap on Solus scan tool and I’m going to try to do the CMP re-sync tonight.
However any thoughts? Will the PCM go into a batch fire
Mode or something - which might explain my glowing header issue.

Re: What’s it mean when engine runs with cmp sensor 180 out

Posted: May 19th, 2021, 1:28 am
by Cheromaniac
Did you install a new harmonic balancer?
A glowing header indicates that you have at least one of two problems; a lean condition or overretarded ignition timing.

Re: What’s it mean when engine runs with cmp sensor 180 out

Posted: May 19th, 2021, 3:30 pm
by Unclewolverine
Or super rich and the fuel is still burning as it exits the cylinders. Rotaries are always run super rich to prevent detonation and they will glow the header red.

Re: What’s it mean when engine runs with cmp sensor 180 out

Posted: July 2nd, 2021, 6:55 am
by b.rudy
Ok so for others searching, here is what happened and why my header was glowing.
Basically everything was fine, ie. timing, tune was close enough(ie A/F ratio) and everything was mechanically sound. I spent countless hours diagnosing only to realize that the "Heatshield Products" "Header Armor" was the reason my header was glowing. Knowing how hot these XJ's run I was trying to combat the heat soak issues these jeeps have and in the process caused another issue. A cherry red header! I removed the expensive header heat shield and bam no more glowing header :roll:
oh well live and learn, I hope this may help someone some day from making the same mistake!