951TurboEuroSpec

I went for a drive in my car tonight after getting it back from the shop. and after about 15 minutes of hard driving my car started to rev on its own up to about 4500rpm and my exhaust header was GLOWING red???

the car has no cat, o2, cross over pipe has been welded 1 inch from wastegate, and is running stock boost,
it was only boosting to 1.3 - 1.4 bar...
Could someone tell me what would cause this to happen??

Ian Carr

running very very very lean and it is getting super hot. VERY DANGERIOUS FOR YOUR BLOCK AND YOUR CAR. Might want to check some fuel things out

Did you say you are running NO o2 sensor?! **** no wonder you car doesnt know how the hell it is running!

951TurboEuroSpec

No o2 cause it is a 86 euro model, im running forge atmospheric BOV i would assume that would cause it to run a little rich??
and the car also started to rev high on its own?

DDP

I also had that high reving thing, not sure what that is. I also just blew my HG, I wonder if mine was running really hot too. The temp gauge was fine though.

Epic2112

The revving thing might be the idle stabilizer valve gone bad. If that's the case it probably has nothing to do with the car running so lean.

951TurboEuroSpec

The car never ran lean before bringing it in. if this is the case whats the best way to see exactly how lean its running, can it be adjusted.

Jfrahm

Man that shop really did a number on your car. It sounds like it has a vacuum leak to me, maybe the intake gasket or any number of hoses and lines.

-Joel.

Dal Heger

Take the car to the shop that I told you about. They WILL sort it out for you. Sounds like you have some issues.

Dal.

mark944turbo

The car should run fine with no 02 sensor as long as the maps in your chips are close to ok.

An engine can not rev itself unless the throttle is letting more air in than it should, or you have a serious leak after the throttle body. But the leak would mean the afm wouldnt see the extra air and wouldnt give any extra fuel, so it wouldnt want to rev quite as much. I would check the situation with your throttle. Was the accelerator cable/pedal binding on something?

Ian Carr

Either way you are running lean. If you are afraid (which you should be) get a wideband and a gauge and see if you are running lean. If you do not want to spend the money get a EGT and see if ti gets hot. But since it was GLOWING my guess is that it was getting VERY HOT. You might want to look into this problem a little more.

Also you said you were running 1.4-1.5 bar? If you are talking about the stock boost gauge, Thats only 7 psi and that is NOT stock boost. That would be another thing to worry about.
-Ian

mark944turbo

"Either way you are running lean"

Maybe, but that is not a fact. I have seen my headers glow on the dyno, when running rich. I have also seen headers glow on a normally aspirated 944.

Ian Carr

after 15 minutes of driving?

I am just saying its some thing you should look into

-Ian

Sam Lin

Glowing headers means nothing, it's normal under heavy load or high rpm. You certainly can't say a thing about a/f ratio based off header color, since a safe a/f ratio will still have EGTs high enough to make iron glow.

Sam

951TurboEuroSpec

Ok had a better look in the engine bay and what do you know a vacuum line was diconnected at the heater valve, put a new silicone hose on it and everything is back to normal no more glowing header issues I dont think its running lean either not with the boost im running, BUT im still having it tested to make sure my air/fuel is correct, it also now idles properly.

The turbo is still the one i had the "mechanic" problems with its just been cleaned and resealed for temporary use till i get my brand new K27/8 7200 from Imagine auto when they are finished testing them. then i can install my fresh crossover pipe with it.
Thanks for all the replys and comments, we will see how this sorts itself, needless to say i will be having the car serviced at another place from now on
thanks.....
JeffP

mark944turbo

Awesome! You really dont have to check if you are running lean anymore. The reason why you were/were having problems is pretty obvious! Just trying to help you save a little money ...

You were only running lean at idle btw, as you would run way rich under boost due to air escaping. So dont worry about it too much.