Headers glowing red
Thread Starter
Burning Brakes
Joined: Apr 2002
Posts: 1,083
Likes: 0
From: Spanish Fork Utah
Headers glowing red
My Hooker Headers were glowing red while I was trying tune the car's PROM. This means I'm running rich, right? Like gas is burning in the headers still?
The guy that was with me was trying to convince me I was running too lean.
Thanks,
Shayne
The guy that was with me was trying to convince me I was running too lean.
Thanks,
Shayne
Safety Car
Joined: Jun 1999
Posts: 3,570
Likes: 3
From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Re: Headers glowing red (sspackman)
Check your ignition timing. Late or retarded spark could also cause gas to burn in the headers instead of the combustion chambers.
Melting Slicks
Joined: Sep 2000
Posts: 3,099
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From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Headers glowing red (Mez)
Check your ignition timing. Late or retarded spark could also cause gas to burn in the headers instead of the combustion chambers.
the late timing scenerio is more than likely the culprit now a cloged cat can also do it so if you have no cat then its probally late timing :cheers:
[Modified by CORKVETTE1, 6:58 AM 11/9/2003]
Melting Slicks
Joined: Sep 2000
Posts: 3,099
Likes: 0
From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Headers glowing red (CORKVETTE1)
super lean will burn hotter than super rich look at a egt meter when the egts go up it means lean mixture when its rich it gos back down
Race Director
Joined: Feb 2003
Posts: 11,671
Likes: 20
From: Lake Wylie SC
Re: Headers glowing red (Mez)
Check your ignition timing. Late or retarded spark could also cause gas to burn in the headers instead of the combustion chambers.
Corvette ***** OG
Joined: Oct 2003
Posts: 4,776
Likes: 21
From: Charlotte NC
St. Jude Donor '05
CI VI Veteran
Re: Headers glowing red (sspackman)
If the headers are glowing red, you're definitely running too lean. I remember rebuilding a Holley 650 double pumper 25 times in one evening. Apparently there was a piece of dirt in there somewhere and the headers were glowing so hot red, you could stick a pencil in the headers and it would melt into it and then you could pull it out... the headers were that hot. I had to rebuild it one more time and finally got rid of any trash.... everything was fine.
You could have other culprits causing it to run lean (eg. cats, timing, etc, etc) but glowing headers is definitely lean.
Mark
You could have other culprits causing it to run lean (eg. cats, timing, etc, etc) but glowing headers is definitely lean.
Mark
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: Headers glowing red (C4 Newbie)
You could have other culprits causing it to run lean (eg. cats, timing, etc, etc) but glowing headers is definitely lean.
Mark
Mark
The statement, "glowing headers is definitely lean." is not true. It CAN be lean, but lean is NOT "definitely" the cause.
Shayne, The first thing I would do is check my timing. Then check your integer and BLMs for indications of rich or lean mixture. An A/F guage would be the best way to check the mixture. Good luck, and...
RACE ON!!!
[Modified by CFI-EFI, 9:46 AM 11/9/2003]
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Thread Starter
Burning Brakes
Joined: Apr 2002
Posts: 1,083
Likes: 0
From: Spanish Fork Utah
Re: Headers glowing red (CFI-EFI)
Wow thanks a lot for all of the quick responses.
There are a couple of things I can tell you for sure. One, the timing is right at 6*. No question about it. The spark advance tables are also the stock ones from GM that I've been testing with.
I got my hands on an emissions probe with a friend at a local shop.
I tried leaning out the fuel pulse width in TunerCat some more and my idle HC's went right through the roof, I mean completely off the chart. They were burning your nose and giving you a headache. At 2500 RPM though, they came way back down to acceptable ranges. It seemed the leaner I went, the higher the HC's went. BUT we could DEFINITELY smell gas. That tells me we're running rich. But that's an assumption
I was going to go this morning and take the 30# Accel fuel injectors out and put the 24# Lucas injectors back in. Some of you know my history with getting this SR installed without leaking, so I'd rather not if I can avoid it.
In doing this I would hope to accomplish getting the fuel levels more stable and not as rich, but now I'm not sure if that's the problem. Where do I go from here?
There are a couple of things I can tell you for sure. One, the timing is right at 6*. No question about it. The spark advance tables are also the stock ones from GM that I've been testing with.
I got my hands on an emissions probe with a friend at a local shop.
I tried leaning out the fuel pulse width in TunerCat some more and my idle HC's went right through the roof, I mean completely off the chart. They were burning your nose and giving you a headache. At 2500 RPM though, they came way back down to acceptable ranges. It seemed the leaner I went, the higher the HC's went. BUT we could DEFINITELY smell gas. That tells me we're running rich. But that's an assumption
I was going to go this morning and take the 30# Accel fuel injectors out and put the 24# Lucas injectors back in. Some of you know my history with getting this SR installed without leaking, so I'd rather not if I can avoid it.
In doing this I would hope to accomplish getting the fuel levels more stable and not as rich, but now I'm not sure if that's the problem. Where do I go from here?
Racer
Joined: Jun 2002
Posts: 428
Likes: 0
From: Dallas Tx
Re: Headers glowing red (sspackman)
You just said the magic words. The HC readings suddenly went up as you tuned leaner.
This is indicating that the mix is so lean that is is erratically igniting. Lean mixes are harder to ignite. So, unburned mix goes out the exhaust. Since the ignition is sporadic (if it always failed to ignite, the motor would not run), when it does ignite, the hot gasses burn the fuel in the headers---they glow red.
Solution is to get the mix back up richer in the RPM bands that the HC was excessive- idle. off idle,etc. If I understand the ECM program correctly, the mix should be 14.7:1 stoichiometric at closed loop idle and part throttle. The short and long term trim will compensate using O2 sensor feedback unless the injector size/pulse width, etc are too far off.
You dont mention it specifically, but check for lean at WOT also. If too lean at WOT, the pistons can cook in a hurry. Here, a tad rich is better 13:1 or so. Make sure your programming does not inadvertently lean out the WOT mix.
This is indicating that the mix is so lean that is is erratically igniting. Lean mixes are harder to ignite. So, unburned mix goes out the exhaust. Since the ignition is sporadic (if it always failed to ignite, the motor would not run), when it does ignite, the hot gasses burn the fuel in the headers---they glow red.
Solution is to get the mix back up richer in the RPM bands that the HC was excessive- idle. off idle,etc. If I understand the ECM program correctly, the mix should be 14.7:1 stoichiometric at closed loop idle and part throttle. The short and long term trim will compensate using O2 sensor feedback unless the injector size/pulse width, etc are too far off.
You dont mention it specifically, but check for lean at WOT also. If too lean at WOT, the pistons can cook in a hurry. Here, a tad rich is better 13:1 or so. Make sure your programming does not inadvertently lean out the WOT mix.
Burning Brakes
Joined: Aug 2003
Posts: 944
Likes: 0
From: Mesa Az
Re: Headers glowing red (CFI-EFI)
"Cat, timing, etc, etc," Do NOT cause it to run lean. Those can be causes for it running HOT, and the headers glowing, but they don't affect the fuel MIXTURE. A lean mixture DOES burn hotter, as pointed out above with the EGT example, but it isn't the ONLY possible cause of headers glowing. My engine runs very rich. In an attempt to pass a smog test, we jacked the timing around. With retarded timing, the rich mixture was burning in the exhaust manifolds and made them turn red.
^ ^
So did it work to make it pass emissions? I think when i finish my rebuild i may need to learn every trick in the book to make it pass. or if you want you can just send me an IM on what you did too. I am interested in how the story finishes.
^ ^
So did it work to make it pass emissions? I think when i finish my rebuild i may need to learn every trick in the book to make it pass. or if you want you can just send me an IM on what you did too. I am interested in how the story finishes.
Corvette ***** OG
Joined: Oct 2003
Posts: 4,776
Likes: 21
From: Charlotte NC
St. Jude Donor '05
CI VI Veteran
Re: Headers glowing red (CFI-EFI)
CFI,
I guess I should have chosen my words more carefully. I wasn't trying to be that semantical but you are right, I was trying to make the point that running lean could "definitely" cause the headers to glow red, I didn't mean to insinuate that was the EXACT and only problem.
Also, I was wrong saying that the cats, etc, could cause it to run lean, I meant what you said... that the ending result from those items could have the headers glow... I didn't literally mean that the cats were causing the lean condition...
Thanks for pointing that out, I guess I should have clarified my statement more carefully. I will make sure in the future.... I was trying to type out my thoughts that I didn't make myself crystal clear.
Mark
I guess I should have chosen my words more carefully. I wasn't trying to be that semantical but you are right, I was trying to make the point that running lean could "definitely" cause the headers to glow red, I didn't mean to insinuate that was the EXACT and only problem.
Also, I was wrong saying that the cats, etc, could cause it to run lean, I meant what you said... that the ending result from those items could have the headers glow... I didn't literally mean that the cats were causing the lean condition...
Thanks for pointing that out, I guess I should have clarified my statement more carefully. I will make sure in the future.... I was trying to type out my thoughts that I didn't make myself crystal clear.
Mark
