today i tried to install my power fc. unplugged the battery, plugged all the wires in and then grounded the wire. then i gave my car power, commander worked everything looked okay but when i turned my car on it started reving up and down for a few seconds then this horrible screaching sound started coming out of my engine bay.

any body know whats up and how to fix it?

 

Screeching sound could have come from a lose belt. The idle serging is because when you first install the ECU I beleive it does a learn process to adapt to your car for idle. Should be with instructions pretty much you let it idle for aobut 10 min while doing little things like turning on A/C so that the ECU can learn idle settings.

Chris

 

ya i know about the ten minute idle thing with the ac and the defrost, but why would the screaching start after i installed the pfc?

 

Just by chance maybe? I cant tell you 100% without hearing it.

Chris

 

ya well im going to try to re install the old computer and see if it still makes that noise.

it sounds like fingernails on a chalk board

 

Start the car up. When/if you hear the sound, open the hood and localize where the noise is coming from while the car is idling...

 

so it sounds like its coming from the alternator or possibly behind it in the actual engine. the car makes that noise then shuts off after about five seconds.

i just re installed my old computer and the car works fine again.

could it be a bad pfc? i bought it off of someone on this forum but it seems to be new and working fine, well until i turn my car on...

 

has anyone ever run into this problem before?

upon closer inspection I realized that there was a wire that was pulled out of one of the harnesses that plug into the back of the ecu (my guess is it came from the smallest harness). its green and its been taped over so it looks like it was done on purpose. It does not affect the performance of the car when the stock ecu is in but im wondering if it is affecting the power fc?

 

is it green and red? i think that may be the speed/fuel cut wire isnt it?

 

i just recently had a really LOUD nasty screeching noise that sounded like it was coming from behind the alternator or behind the engine. Turns out my started wasnt disengaging because of a shorted ignition switch.

Probably isn't your problem but swapping out the switch completely eliminated the sound which i originally thought was a belt or something.

 

thats sounds interesting because the last time i tried turning my car on with the power fc the screatching stopped when i turned the car off but there was this loud buzzing noise coming from the same area and would not stop until i unplugged the battery.

 

no just green

 

i dont think thats the issue because even if the starter would not disengage the starter would just burn out. it would not affect the car from staying on would it? and why would it work normally again when i switch my old computer back in?

 

yea true......however my car did stall out once or twice with my ignition switch issue.

good luck

 

if the started stayed engaged it would start shearing teeth off the ring gear and the starter gear, that would be a very bad bad thing and im sure that you would know what it is right away. i dont beleive that the starter rotates as fast as an idling engine.

 

hmm do you think its a problem with the power fc itself. is there anyway of telling on the commander if the power fc has been compromised in anyway?

 

not really but you could go through the sensor check and see if anything is highlighted.