Hi there,

I have an interesting situation that has nearly driven me insane. Whether hot or cold, idling or driving, it will randomly buck. For example yesterday morning drove fine to work. Yesterday afternoon it was terrible. This morning it played up for nearly 5 minutes. This afternoon drove through 150 miles of mixed traffic like there was never anything wrong with it. It may only do it once or it may do it for 30 minutes. If it is doing it at idling it usually wont stay running for long. I have replaced: front o2 sensor, cam sensor, crank sensor, coil pack, wires, plugs(NGK), air filter, IAC and controller(all OEM parts where applicable). Although I havent replaced the TPS from prior attempted diagnostics it runs the same with it unplugged.

 

Any input would be appreciated

Especially because of the fact that it dies sometimes, it's intermittent, and you didn't mention whether a check engine light was present. I would swap out the MAF for a known good one.

No CEL

I will try the MAF this weekend

 

Thanks

Let me know how it goes, sounds like that could be it to me. They rarely throw a code when they are failing.

Although I havent replaced the TPS from prior attempted diagnostics it runs the same with it unplugged.

That's interesting. That could mean the ECU is already in "limp mode"

where it doesn't pay attention to certain sensors because of a problem related to one of them. Any OBD2 vehicle would have a CEL because of this though. Also unplugging the TPS would set a code, and illuminate the CEL.

 

When you cycle the key ON to start the car, does the CEL illuminate for a few seconds then go out?

There are two things in addition. The temperature extremes causing an arc track by humididty defeating spark to one cyl. I was going to say injector but that , I'll leave open and be flooded with info or not .

I have experienced a bucking and cel then no cel when it is brief. The exhaust is rich at those times.

Coincidently the strobeing across input of any site is similar to the inputs of the ecm/ecu of those days. Too many throws a code and there are certain triggers which are priority. A leaky injector isn't good and wears away a cylinder.