Header glowing bright orange

[ktm racer 419]

blehblehbleh

seeing that there isnt an exhaust restriction and its not running lean. im leaning towards stretched timing chain.

and a new motor.

ill pop the timing cover and take a peek before i get rid of the motor though.

 

[lawsoncl]

blehblehbleh

seeing that there isnt an exhaust restriction and its not running lean. im leaning towards stretched timing chain.

and a new motor.

ill pop the timing cover and take a peek before i get rid of the motor though.

Last time I saw a header that hot was after I accidentally did a dyno run with the timing pulled back to zero. It made crap for power, but we did get 30-psi boost out of the turbo since half the fuel-mix was burning in the exhaust pipe. The exhaust hit 1600*F during the 2 minute run.

 

[Ecomike]

If it was a clogged exhaust he would notice the power loss big time.

I had that problem with my 73 Ford LTD. Turned out to be a bad dizzy vacuum advance valve on the dizzy. It was rusted and locked in place, so it got no vacuum advance, in other words the timing to fire the plugs was very late so the fuel was still burning when the exhaust valve opened. It was cherry red at idle in 40 F weather. I would look for something that could make the CPS signal late, like a jumped timing chain perhaps, or burned valves on the head that are leaking, or ex-valves stuck slightly open?

 

[Fixn2xlr8]

Have you checked to see if your cat is glowing?

 

[ehall]

To me it looks like you are running rich or your ignition timing is off.

As a general rule, engines use rich mixture during cold engine startup so that some of the fuel would burn with the exhaust valves open. This helps the O2 sensor(s) and catalytic converter(s) to heat up quicker.

The other possibility is that the ignition is firing late, and some combustion is occurring when the exhaust valves are already open.

Bunch of possible causes for either of these conditions.

 

[ktm racer 419]

Have you checked to see if your cat is glowing?

cat is fine. just the header.

To me it looks like you are running rich or your ignition timing is off.

As a general rule, engines use rich mixture during cold engine startup so that some of the fuel would burn with the exhaust valves open. This helps the O2 sensor(s) and catalytic converter(s) to heat up quicker.

The other possibility is that the ignition is firing late, and some combustion is occurring when the exhaust valves are already open.

Bunch of possible causes for either of these conditions.

like i said. fuel trims are fine. and running very lean would make the header glow.

im going to pull the dist cap and see how much play i have on the dist when i turn the crank back and forth by hand.

i dont know what would be considered acceptable though lol

sloppy timing chain would cause the valve timing and ignition timing to be off



no codes either.

 

[ehall]

cps and cks could also cause the ignition to be weird, fuel delivery would lag too

 

[Flyfisher]

Not sure if this will help chase the problem, but I'm leaning towards spark/ignition problems. I had a '66 Land Rover that experienced the glowing exhause manifold once...was running like crap too. That problem turned out to be mis-adjusted points (remember those?). They weren't tight and gap was too small.

Maybe some of the more informed XJ gurus can translate that diagnosis into modern ignition terms.

 

[MoparManiac]

Possibly dumb idea, but could a cracked flexplate cause this...?

If the teeth on the flexplate were off a bit, maybe it could cause something like this?

Shot in the dark.

 

[kastein]

I guess it could... you'd hear the jeep coming like 2 miles away though if it was cracked that badly.

 

[MoparManiac]

I guess it could... you'd hear the jeep coming like 2 miles away though if it was cracked that badly.

True.

 

[ktm racer 419]

timing chain seems tight.

 

[ktm racer 419]

engine vacuum is 16 in-hg

thought i checked that earlier and it was fine so i shrugged it off. maybe i should write this shit down lol.

also swapped out my map and intake air temp sensor with known good units out of boredom and nothing changed.

 

[ktm racer 419]

im gonna put a stupid engine in it and hope it stops doing this.

 

[Ecomike]

Might be smarter to put a smart engine in.

Why not use an old fashioned timing light and see if it gives any clues as to the problem? I would replace the Distributor, and make sure the timing is right when you set it. I would also try a different ECU/PCM before swapping engines.

 

[ktm racer 419]

Might be smarter to put a smart engine in.

Why not use an old fashioned timing light and see if it gives any clues as to the problem? I would replace the Distributor, and make sure the timing is right when you set it. I would also try a different ECU/PCM before swapping engines.

tried the timing light, cant see the damn marks on the 4.0. too much crap in the way.

i suppose we could pull the belt and a couple pulleys to see it lol.

but the motor has low vacuum.

leaks oil almost everywhere

has blow by

burns a quart every 1000 miles

and no balls

im afraid of what a compression test will tell me. but i bet it aint good

 

[Ecomike]

May just need the head replaced.

I thought idle Vacuum was 16? IIRC that is OK.

What oil are you using?

I suspect your problem is late timing (which also explains "no balls", LOL), possibly electronic, PCM-ICM Dizzy, which a new motor would not fix.

tried the timing light, cant see the damn marks on the 4.0. too much crap in the way.

i suppose we could pull the belt and a couple pulleys to see it lol.

but the motor has low vacuum.

leaks oil almost everywhere

has blow by

burns a quart every 1000 miles

and no balls

im afraid of what a compression test will tell me. but i bet it aint good

 

[ktm racer 419]

i use rotella 15-40 usually

but lately ive been throwing 10-30 whatevers cheapest (winter time)

 

[1990JEEPXJ]

there is no loss of power

and no balls

well which is it?

 

[ktm racer 419]

well which is it?

no loss of power compared to when before i had the issue

no balls, because the engine is pretty tired.


ANYWAY

drove it 350 miles to pennsylvania last weekend. carpet was hot to the touch above the cat and muffler

lost spark while in pennsylvania.

diagnosed it as the coil. replaced coil. fixed it.

and on the way home my floor didn't get warm at all.

effing weird, but im not complaining