Check engine light on

[matwell]

A small problem with my 92 typhoon, driving at constant speed (i.e. on cruise control) the engine check light comes on. iIf you then speed up or slow down it goes out. Also comes on if idling for about 30 mins, have pulled the code showing code45 (oxygen rich ) i belive. Have changed the 02 sensor but problem still occurs, have tried lowering fuel pressure but that didn,t work!! Driving it daily the problem does not occur (various driving speeds). Only on the highway.Would like to know what the cause of this is, one of those enoying little things. Happy christmas to every one..

 

[Bill Z]

Re: Check engine light on

A rich mixture is caused by ether too little air or too much fuel. My guess is that one or more of your injectors are sticking.

Try some injector cleaner stuff first and see if that doesn't clear up the problem after the second tank full.

Than is my suggestion. Good luck.

 

[matwell]

Re: Check engine light on

An injector fault was what i thought it might be, have tried cleaner last time this happend. perhaps this is why the fuel pressure drops away after you swicth the engine off ,cheers

 

[BillC]

Re: Check engine light on

Before you waste too much time or money on guessing, try hooking a scan tool or Datamaster up to the truck and see what's really going on in the computer.

Look at O2 millivolts, and see if it's really going rich. Look at the short and long term correction values, and see if the computer is trying to correct the fuel. With this info, we can give you a better diagnosis.

 

[VermontTy]

Re: Check engine light on

An injector fault was what i thought it might be, have tried cleaner last time this happend. perhaps this is why the fuel pressure drops away after you swicth the engine off ,cheers

I'd say injector as well; if you're losing pressure, its either the check valve in the pump, a bad regulator, bad injector, or a leak in a fuel line somewhere. I have the same thing going on with my truck right now; the pressure leak, and I'm 99% sure its an injector; the end of a couple were cracked and broken, so I think its just leaking like a sive.