Rough idle 4A-FE - Toyota Nation Forum : Toyota Car and Truck Forums

90 GP · 05-23-2004, 06:58 AM

1990 Toy Corolla 4A-FE engine. Ocassionally it idles rough. Has new plugs wires, cap and rotor,air filter. Other than this runs well. Any thoughts on how to correct or is this characteristic of this engine. Would appreciate any input.

mykngdom4avvti · 05-25-2004, 06:29 PM

Since the engine is a 4A-FE, Im assuming it is fuel injected. I would probably check that the MAP sensor is okay, as these sometimes fail on Toyotas.

Nico · 05-28-2004, 02:05 AM

What you can do is spray some carburator cleaner in your throttle body (in the little whole that sucks air). It can perhaps do something. If this along with some other things like what you did doesn't do anything, I would really recommend you to go to a garage and make a compression test, it only takes a few minutes so it won't cost you a lot of monay but at least you'll know if your internals are ok. Bad idle can be a sign of loss of compression on many Toyota's.