I replaced the O2 (Denso) and TPS (NOS AC) Friday, car really seemed to be running well over the weekend, made my 100 mile commute yesterday with it feeling peppy for once. Even the idle improved, more stable, but since has gotten slightly erratic again with the rich/sluggish response's return. This morning, the Check Engine light came on for the first time since owning the car. Read code, 45 which can be a number of things. I did inspect the fuel injector a few weeks back, had a nice fan pattern at idle and under throttle.
So far I have replaced:
Temp sending gauge
TBI rebuild kit (not yet installed)
I know some expressed concern with me replacing parts without testing system components. The car sat for 17 years, almost every part appears to be original, I am refreshing the entire car, short on time getting my motorcycle ready for the season so I can put the car in the garage, drop the cradle for the refresh. My thought is it will all need replacing, just finding the fine line of what is immediately needed to keep it efficient while I commute until the bike is ready so I can devote more time to it. I will test the fuel pressure by this weekend, ordering the adapter from Actron tomorrow.
I notice if holding the throttle at a light steady amount, I can feel a slight pulse/surge which seems to come and go, though none of the gauges show this. The MPG seems to be half of what it should be at this point, though at times it gets close to 30. This tells me with it being intermittent something is either failing or possibly a loose connection with the issue coming & going randomly like it is.
The PO replaced the fuel pump, dropped/cleaned the tank. Also had a mechanic look at it in January when I first bought it as it ran out of gas taking it home because at the time I had no clue the fuel sender was bad. He reported no visual issues, tested it and informed me it was a bad sender and that it was just empty.
So I am thinking fuel regulator, injector as it does act rich. Hopefully I can get some daylight tomorrow to inspect the plugs.
I still have to get to the bottom of the wobbling timing mark, certainly feels like I am dealing with multiple layered issues.
Odd thing is, the only codes I have received since resetting it when I first got it have been 22 and now 45. Are codes not always thrown when a component is bad?
So is it possible that whatever the issue is, it's something not read by the ECM, like the injector leaking or fuel regulator?
[This message has been edited by mckaymotoworks (edited 04-23-2014).]