Hellbillydeluxe

Hi!

I'm getting desperate here!
I have a -91 Camaro z28 convertible with manual gearbox.
This spring it started to die when i whas driving and after a while pressed down the clutch. No errorcodes. I have changed sparkplugs, ignition wires, the temperature sender near the intake, changed the IAC, meassured the injectors. Today when i went for a testdrive after changing the IAC it started to missfire after 20 minutes at low speed. When i got home i checked for errorcodes by flashing the service light. Now the fan and the enginelight whent on and off randomly! Computerbox failure?
Link to youtube https://youtu.be/kNqUL5tjuCA

Please help!

Marcus

Hellbillydeluxe

This is ehat happened when i tryed to flach codes, listen to the relay!

https://youtu.be/kNqUL5tjuCA

The fifteen minutes later all was normal again!

There in a Superchip installed maybe something wrong with that?

ex-x-fire

When its running bad check the fuel pressure.

Hellbillydeluxe

I will change the fuel filter if that is bad and also check for groundproblems to the ECU.
To be continued.......

Hellbillydeluxe

Hi!

I am looking over the wiering and came across this terminal. Looks like it been pretty warm. Anyone know what it is for? Located on the upper passengerside.

Hellbillydeluxe

I have found what was causing the burning smell. Anyone know what its for, can it cause the missfiering?



Thanks / Marcus

fireburdluvr85

Knock sensor and yes it'll cause a host of problems.

Hellbillydeluxe

Problem solved!
That is the radiator fan switch, and with it disconnected the car runs fine!
Won´t get any errorcodes from that, and with a bad Connection the ECM failed and the car missfired and no idle. Drove 7 miles yesterday with no problem!

Thanks for the input!

judoka_ca

Hey are you sure that was a radiator fun switch not a knock sensor ?? as the one on the photo had a white wire and as I remember correctly it should be a black wire for fun switch and white wire for Knock Sensor that should be mounted close by

Hellbillydeluxe

Yepp, sure. when i ground it the fan starts. Electric schematics says grey. Black is to the fan.

CatmanFS

Yeah that little fan switch uses the same connector as a knock sensor. That fan switch has always been a mysterious little guy. Just one of those things that always seems to come up eventually.