pfc question

[kyles_r32]

Hey guys ive noticed that when i come to a stop light and im idling the timing is at like 27 degrees, so i tap the gas and then it will drop done to 15 where it should be. Has anyone came across this before? Ill have to try to see if i can catch it on the map tracer but i don't have a laptop to hook up yet so im just using the controller. Also cold start has been acting up, once it hits around 68 degrees celsius the idle starts to hunt around, it almost sound like its hitting a fuel cut. Once it hits 80 degrees celsius its fine.

Thanks Kyle,

[bobbo]

You're gonna need to look at your timing tables to see what your idle is doing.
Also if the car is hunting and acting like it's "hitting the fuel cut" which you can confirm by watching your injector duty cycle, the car might be idling higher than what the PFC is commanding.
The PFC doesn't control idle as well as the stock ecu so if it doesn't like the idle rpm it takes the easiest route to bring the idle down. Cut fuel.

[Skym]

Stock ECU has tables x2 it can use for kicking revs up when slowing down. I think it activates when TPS touches idle contact, as backing off throttle makes revs flare up and car can buck a bit which tells you that it's switched.

One thing I found that makes rpm flare up and stay up with stock ECU is intake airleak. Another symptom of airleak is fluctuating rpm needle on dash.

TPS settings would be the other to check, as idle contact on TPS can bend over time and cause problems.

[kyles_r32]

So i haven't really looked into the ign. timing but with the cold start problem it definitly is hitting a fuel cut. It will bounce around at around 1300 rpm. If i unplug the temp sensor going to the ecu it stops. Maybe my cold start settings are wack on my pfc or the temp. sensor is screwed?

[Skym]

Probably is the coolant temp sensor for ECU. ECU looks at coolant temp sensor to know where to be on fuel, ignition, idle rpm tables when warming engine up.

[Supraclean]

I was just on the dyno and had this problem! Tps was not reading at all due to a shielded wire touching what I believe to be a ground wire and the ecu went into a safe mode/cut. So check your Tps is geting power and the pin at the Ecu.

Hope that helps.