[yuanti]

My '87 GMC Safari was running pretty rough last week all of a sudden. I would put the van in drive or reverse and the oil pressure would bounce around, idle was very rough. Acceleration was slow and lacking in power.

I opened up the hood and the interior to check everything out and found that two of my passenger side spark plug wires had come out of the tie-down above the manifold and were basically burned up from resting and rubbing against the exhaust manifold.

I replaced the wires and the plug while I was in there but noticed this opening on my passenger side exhaust manifold. I cant find my service manual but I'm thinking there used to be something attached there. Any ideas?

 

[Smiliesafari]

There was a pipe that ran from the manifold to the air filter housing. It transfered warm air to the intake. It was a mileage thing.

 

[skippy]

i was told it was to bring warm air to the carb/throttle body to keep it from icing up in the winter. i remember an old 77 dodge van that kept icing up on me till i noticed that tube was gone , i put a new one on & it stopped my problems . am i wrong ???

 

[remark123]

No, you is right skipster! That is the manifold pre-heat for the TBI/carb. There should be a little piece of corrugated cardboard tubing that goes from the round opening up to the bottom of the air cleaner, where there is a thermo valve that opens when the thermostat isn't open to allow air that is preheated by the manifold into the air cleaner, so that A) the engine doesn't stumble while it is warming up, and B) to reduce the emissions from the rich mixture until the engine enters the "open loop" phase. I believe that you can usually find aforementioned tubing in the "Help" section of the local auto parts store... :dance:

 

[kidhauler]

The proper name of the little tube is "Thermostatic air cleaner" or TAC for short. They are usually only about 3 dollars. Get the proper hose and don't just use a chunk of cardboard. I have seen people do that and it lit of fire.

 

[yuanti]

=) Yeah I cant imagine using cardboard for that considering it is off the exhaust manifold
The pipe probably came off a while back during one of those times I heard somethign metallic sounding fall or drag and couldnt figure out what the heck it was.

Thanks for the input everyone =)