Tech Area

Hard Start/High Idle (4 Cyl)

Question: I am buying an '84 sport coupe (2.5l 4cyl). Everything seems good, except for two things: the engine needs a little ether sprayed in the air filter to get started. Once the engine is started, it runs itself up to right around 3000 rpm, and doesn't slow down. We *think* the starting problem is due to a vaccuum leak somewhere, but cannot find it. The fast idle has us puzzled though.

Answer: It sounds like a large air leak is causing both problems. Probably too much to be a small vacuum line.

First check the PCV valve. It is at the base of the Throtle Body Injection (TBI) in the large hose that runs from the valve cover. If stuck open, it will allow massive amounts of air in. You can plug it from the valve cover side.

If OK, then carefully (it's flammable) spray WD40 around the base gasket of the TBI, EGR valve, and along the intake manifold gasket. A slight rpm increase will occur when the deteriorated gasket is found.

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