If I rev my car in neutral the center 2 header tubes glow red! Does that mean my car is running lean? Also when the car idles the fumes make your eyes tear & the stinch get all in your clothes!! There is no visible smoke & there is no cat on the car.

 

Both of those symptoms (glowing headers, exhaust that burns the eyes) indicate late ignition timing. Check it with a timing light, and I would expect that you are 10 or 15 degrees late.

 

Yes, glowing red headers can indicate an extreme lean condition. Check your timing as well as rustydawg mentioned. It could be both!

 

Part of it is a timing problem, but I think you're running rich too. We had this problem on an LS1 and that was the two reasons.

 

A lean condition and late timing are my choices also however you mention only the center 2 tubes are glowing.

To me that would mean only those cylinders are running lean which doesn't make any sense. Check the header gaskets. Check the spark plugs (very clean and white is lean). Check in intake gaskets. Maybe those cylinders are sucking in extra air from a bad intake gasket.

Running rich has a cooling effect which lowers exhaust temperatures.

 

Glowing headers is definatly a danger sign.
You need to correct this or sever engine damage can result.

Late ignition timing is usually the cause. But it can also be rich or
a lean condition or a combination. Since it only happens on 2 cylinders I'd check the firing order. Wouldn't be the first time.
The timing may not be advanceing when yu rev it.
Or the injectors are faulty.

Any number of ECM programing faults could cause this too.

 

Doh! I never even thought of a TPI system. Yes you could have a couple of bad injectors not supplying enough fuel to those cylinders.

 

Running rich has a cooling effect which lowers exhaust temperatures.


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Not always. Rich fuel mixture tends to burn in the headers. When timing is late.

 

I'm sorrry ba bit drunk right now, but what about a clogged cat, but yes a lean conditno will cause it too.

 

Hey Mark, when you sober up and can read straight re-read 86Tra/maro's post. You might find out he doesn't have a cat at all. But you've gotta get rid of those pink elephants first... hehe. Damn, that make me want some beer right now. So raise your hands, those of you that are gonna have a hangover on Sat. at the thirdgen nats... ME, ME!!!! *Harry raises both hands*

What Mark is seeing right now----> :lala: :lala: :lala: :lala:

 

The burning eyes is probably an exhaust leak. Replace your gaskets with dead-soft gaskets.

 

owww, my head hurts.

 

If it's running rich it could also make the headers glow, what happens is the explosion in the cylinder still burns as the exhaust valve opens. In other words, it shoots flames out the exhaust ports. I had that problem with mine because I had it running too rich. Once I leaned it out a bit, no more problem.

Stephen has a good point with the injectors though, it could be going two ways. They could be clogged, or just letting too much fuel in. A good and easy way to check if they're leaking is to put a fuel pressure gauge on it, prime the system, then turn the igntion off. If pressure starts to drop automatically, you've got problems with the injectors.

Timing is also an issue of glowing headers, but it shouldn't only effect 2 primary tubes, all of the tubes would glow.

 

The 2 center tubes on both sides of the motor glow first & then the remaining tube starts to glow. I have the dist set at 6degrees and my chip has 15degrees at idle. At about 2000rpms the timing is at about 25deg. with light throttle input from the tps sensor.Ive tried disconnecting the various vacumn lines & plugging them but I still get the burn your eyes stinch from the exhaust. thanks again.
njdaewoo

 

i would definitely play with the timing, especially since you have all those mods done. i'm running about 18° advance, it hates anything less than 12. pull the plugs out, they should be a light tan color, yours will probably be very white and possibly melting from the heat. if they are you need to move to a colder heat range plug. i'm assuming you know to disconnect the timing connector when you set timing so this is just a reminder

 

along with timing could it be possible that those 2 cylinder exhaust valves are not closing properly? Although timing not advancing and late timing will do this but how do we explain the gas fumes if it is running lean?

 

Yes I know about setting timing.
Question:along with timing could it be possible that those 2 cylinder exhaust valves are not closing properly?
Answer this:
Its not only the 2 center header tubes, its all 8 of them. The 4 center tubes glow red first & the outer tubes. Maybe my 30lbs SVO injectors dont like chevy engines I have the injector constant set at 32lbs with the chip burning program. my fuel pressure is 35 @ idle & 45 @ wide open throttle. Remember the headers glow red while the car is revved in neutral at a steady1800rpm for about 45 seconds. I have no idea of what to do about the burning eyes at idle either.

 

Pull out all your spark plugs and take a look at them. This will tell you a lot: if you are rich or lean, and if all your cylinders are running evenly.

 

the fuel actually burns in the cylinder.detonation is more like explosion

dave

 

I think what he is trying to say is that the timing is a little late and the fuel is too lean so as the exhaust valve opens, the fuel is still burning causing the combusting gasses to heat up the two header primaries. Typically a lean condition would have this affect on the rear cylinders as they tend to be the ones to lean out first.