Glowing Exhaust Manifolds

Hi I have an 86 GT v6 and I just painted the upper intake plenum and ported it out after putting it back on and starting up the fiero it was ideling very high at 3000 RPM and then I noticed that one of the exhaust manifolds was glowing red, when I was putting the intake back on I forgot to put on the gasket were the EGR tube bolts up, I also forgot to put the gaskets were the two intakes meet, could this be the cause of the problem??

Thannks

My 87 GT did that when I first got it....ended up finding out that some lazy a$$ figured it was too much trouble to change the three front plugs. They were all originals with about 125k miles on them and 2 of them were fouled out. I'm thinking that some unburned fuel was reaching the exhaust manifolds and then burning in there....I could be wrong, but I don't see a way that leaving those particular gaskets out would cause your problem.

My 4cyl header used to glow as well, the problem was bad valve leaks and a cracked head.
In your case, I think those missing gaskets are causing an intake leak.... extra air, hotter combustion, glowing manifold... it DOES make sense.

What about the hot idle does that come with the glowing manifolds?

High idle is often caused by air leaking into the intake manifold. The missing gaskets are certain to cause such a vacuum leak, and it's almost 100% certain that's where your high idle is comming from.

So if I put the EGR gasket and the gaskets between the two manifolds it should stop both problems?

I put all the gaskets back on and made sure all the bolts were tight and after running it, it was ideling at about 2300-2400 And the front exhasust manifold was glowing but in one spot, The first time without the gaskets it was ideling at 3000 and the whole manifold was red any suggestions? By the way I only ported out the upper manifold and I put it back on because I wanted to see if I would have any trouble installing it the lower manifold will be done sometime this week could that also have an affect on it?

More than likely the glowing manifold and the fast idle is caused by an air leak in the intake manifold. Since you had the intake manifold apart, squirt some oil aroundthe gaskets with the engine running. When the engine idle changes, you found your leak.

For what it's worth,

fIEROWISEGUY

Just like 3 n 1 oil or WD40? or what?

Any light lubricant will do. Carb cleaner works GREAT, because if you have a leak the engine rpms will change quite a bit when you squirt the leak with it.

I know this is bad news, but it must be said. You could have warped the intake plenum if you didn't torque the bolts evenly and in the proper order.

Does the order really matter because I usually do one on one side and then the other and so on, because the intake wasn't ported to much I know that because I had a professional check it and it's ported so that its not bigger than the gasket..so what do I do now?

Not to sound like a jurk or anything, did u check the butterfly in the intake or the gas cable just to be on the safe side. and what should the fiero idle at mine idles at like 1600 so i was just wondering.

When you first start it up, and the engine is cold, 1600 sounds about right....once it gets warmed up it should drop to somewhere between 700-900 RPM.

Where abouts is the butterfly? When My Fiero is cold it idles at about 2100 then when its warmed it drops to about 1100-900

Check the vacuum hoses for any cracks or any you may have forgot to reconnect. with a 900 rpm idle the leak should be quite small.

By butterfly, he means the throttle plate in the throttle body. While we're talking throttle body, make sure your tps is adjusted properly.

Sorry Im kind of new to all this stuff Because I just picked her up a while ago were can I find the TPS?

Side of the throttle body, black thing with wires plugged into it. On occasion they get knocked around and thrown out of adjustment when the plenum is removed and reinstalled. This can cause a high idle, but wouldn't explain the glowing manifold. (if it hasn't gone away yet)
Up until now, we've assumed the intake manifold had something to do with the glow, but it could just be a coincidence you noticed it at the same time. Another cause for the glowing manifold can be distributor timing WAY off, and a plugged converter (exhaust will often make a whistle noise) will do it too.

The exhaust isn't making any funny noise and I havent touched the timing either than taking of the dist. cap but put it back the same as it came off Im going to go and get all new gaskets for the intake EGR and whatever else I need

just wondering if you found the problem

Well I just bought all new gaskets for everything and will install it all soon So i will post then

High idle is often caused by air leaking into the intake manifold. The missing gaskets are certain to cause such a vacuum leak, and it's almost 100% certain that's where your high idle is comming from.

:iagree: