shi89max

could anyone tell me whats wrong with my car, every so often my car bucks and crap,and the car will hestitate when i try to accelerrate, But if i floor it and drive the car flooring it in every gear the car drives fine. also when it does this the exhuast sounds funny. does anyone know what might be wrong

94SUPERMAX

Probably just needs a tune up.

tom200K

Might be an oxygen sensor. It's easy to overlook and hard to get to.

Tom

nubiannupe

iTrader: (9)

Actually it might be either the tune up OR the O2 sensor. It may also be a clogged cat, which is what MY problem was, I believe. I still have to check the sensor, and I've got an appointment to get a complete tune up next week. I'll get to the bottom of this!!!

tom200K

I have a little more time than I did earlier this week, so I checked with my 1989 Nissian Service Manual. They had a few things that are easy to check.

They reccommend checking spark plug and spark plug wires (no surpize).

Also check the Air Duct for leaks. A leak will throw off an air flow detector.

Next they recommend doing a fuel mixture ratio tests. Too complicated to get into here, but it implies that changing a fuel filter might be a good idea.

Finally they suggest disconnecting the electrical lead from the exhaust gas sensor. If driveability improves, replace the sensor.

I realize that you are taking to garage, but sometimes it helps to know what to look for. Good news, a clogged cat wasn't on the list.

Tom

FiSH

Does this problem mainly happen at around 2000 rpm cuz if it does I have the same problem that occurs once in a while...
No idea what it is...

Dave

brubenstein

Check/clean the connectors to the MAF (Mass Air Flow sensor) and TPS (Throttle Position Switch). Dirt and corrosion on these connectors can cause intermittents on the signals going to ECU, and throw the mixture off. You and also clean the sensor in the MAF by spraying some brake cleaner on it with the engine off.