I just installed some new parts on my L-98 and when breaking in the new cam, running at about 2,000 rpm , about every 5 minutes the headers were getting so hot to the point of glowing. Here is the list of new or modified parts:
-Comp Cams 464 lift 222/226 duration 114 degree lobe centers
-PJ gear drive
-Pocket Porting on stock heads
-Relocated MAT sensor
-1/6 ratio rockers
I already lowered to fuel pressure to 40lbs and advanced the timing to 12 degrees. It seems to go maybe 6 or 7 minutes now before glowing. It also smells very rich when standing behind the car. Any help would be appreciated. Thanks!

 

I would think you are running way lean with that fuel pressure, but you should be in closed loop at a relatively steady 2,000rpm (i.e. not WOT).

That tells me your ECM is enrighing the charge way too much; have you checked for codes?

A scanner would tell you what coolant temp is being seen by the ECM and if the O2 sensor is functioning.

Another possible problem would be a serious vacuum or exhaust leak in front of the O2 sensor.

You might also check compression on a cylinder to assure the cam was installed correctly.

BTW, does the setup have LT headers or stock headers?



[Modified by 65Z01, 4:58 PM 5/29/2003]

 

Mine did this too while I was breaking in a roller cam that did not need to be. :bb

Any how, some problems I ran into.

Vacuum leak on the back runners, where they meet the base.
Timming was off. (remember to remove the esc wire to set the timming)
Fuel pressure was all over the place.

on a side note, when I run the stock exhuast (manifolds and cats) and 1.6 RR my manifolds still glow, so I put the 1.5 back on when I run the stock exhuast.


[Modified by bill mcdonald, 2:45 PM 5/29/2003]

 

Timing looks too advanced, you will need a chip made for those mods, and you are probably running lean and/or have a clogged cat.

 

I thought too much advanced timing caused the intake to heat up and retarding too much caused the exhaust to heat up. Must be these new computer driven high tech engines.

 

your timing is off or your running lean

 

:iagree: :smash:

 

Well, we see this on our race engines depending on how they are tuned. Two things combined seem to do this even if the fuel ratio is super rich...

Retarded cam timing and 1.6 rockers. Did you degree the cam when you installed it?

But our engines have never done it at 2000rpm, always WOT on the race track (circle track).

 

I had the same problem, engine temp was 170 but headers were glowing. Do not run the car like that, I caused a few problems, burn't wires etc by letting it run. Turned out it was mostly due to retarded timing. When the timing is retarded the fuel will burn in the headers, hence red hot headers.

After setting timing +12 and adjustng idle and fuel pressure to 42lbs car runs great.

Good luck.

 

With a stock chip, and a cam like that, I dont think the timing would be far enough off at 2000rpm to cause glowing headers..

My guess (you arent going to like this) is that you have your timing chain off 1/2 a tooth. Another forum member did a cam swap last summer, had glowing red headers, and thats what it turned out to be.

-Mark

 

This happened to me before and it freaked me out. If you keep driving it like this then later you will notice the car won't accelerate much and then later it won't start. The reason why is the cats are clogged. I had to have mine replaced. Whatever you do do not keep driving it like this otherwise you are going to warp something.

 

The glowing is caused by unburned fuel going into the headers then burning. Main cause of its, retarded timing. MAKE SURE you have your base timing at 6* with the ESC unplugged! Then plug it back in, clear the code from the computer by disconnecting the battery.

Also something we all should do time to time. With a dial type timing light. Unplug the ESC, and put the **** to zero. Verify that mark on the timing balancer is at 6*. Then plug the ESC back in. Go throught the clearing of any codes as mentioned above. Then with the help of a scanner, see what advance you are running at idle. Probably between 18-25*. Whatever the scanner says as your timing, set the knock on the timing light to that. Now verify that the mark is now located at 0 on the timing plate. This ensures that 1. you getting the proper advance that the computer is trying to give, and 2. your balancer did not spin on the inner hub and your base timing is all hosed up. And you think your setting the base timing at 6*, but its really -5*.

Just a little advice for the folks out there. Its a little trick that could help you figure out a problems like this relatively easy.

Also with a problem like this, MAKE sure that your entire ignition system is up to snuff. A weak spark can cause this also, as all the gases are not burning.

One last thing...did you degree the cam? A retarded cam will mess everything up too. :cheers: