Idle problems ................ still!
12-18-03, 09:52 PM
#1
Idle problems ................ still!
I've been working on this for awhile and can't figure it out. Here are the symptoms:
Once the car warms up the idle varies or surges between 1200 and 1500 rpm. Cold, it won't idle at all, but that I can live with it. It doesn't take more than 2 minutes before it will stay running and starts the surging idle. Normal driving and hard driving the car performs great. No hesitations, boost comes right up and stays up. Power all the way to redline.
Here is what I have checked:
Pressure tested the TID, intercoller and the rubber 90's: no leaks. Sprayed carb cleaner all over the engine looking for vacum leaks: none found. Created some of my own vacum leaks to see if it made it worse: no affect. Replaced all the vacum hoses when we rebuilt the engine 1800 miles ago. Adjusted and tested the TPS from one extreme to the other with no affect. Tested the BAC valve: tested ok. Disconnected the BAC valve: no affect. Cleaned the fuel injectors: no change. Tested fuel pressure at the pump and at the rail: within specs. Iginition is set as close to specs as I can get with the idle the way it is. Checked the positon of the CAS at TDC to my other TII ( that runs fine) and they are the same.
Here are the mods:
K&N filter
S5 turbo and manifold
S5 throttle body
street port
RB 3" turbo back exhaust
ACT clutch and pressure plate
I'm all out of ideas.........................
Once the car warms up the idle varies or surges between 1200 and 1500 rpm. Cold, it won't idle at all, but that I can live with it. It doesn't take more than 2 minutes before it will stay running and starts the surging idle. Normal driving and hard driving the car performs great. No hesitations, boost comes right up and stays up. Power all the way to redline.
Here is what I have checked:
Pressure tested the TID, intercoller and the rubber 90's: no leaks. Sprayed carb cleaner all over the engine looking for vacum leaks: none found. Created some of my own vacum leaks to see if it made it worse: no affect. Replaced all the vacum hoses when we rebuilt the engine 1800 miles ago. Adjusted and tested the TPS from one extreme to the other with no affect. Tested the BAC valve: tested ok. Disconnected the BAC valve: no affect. Cleaned the fuel injectors: no change. Tested fuel pressure at the pump and at the rail: within specs. Iginition is set as close to specs as I can get with the idle the way it is. Checked the positon of the CAS at TDC to my other TII ( that runs fine) and they are the same.
Here are the mods:
K&N filter
S5 turbo and manifold
S5 throttle body
street port
RB 3" turbo back exhaust
ACT clutch and pressure plate
I'm all out of ideas.........................
12-18-03, 10:04 PM
#2
Rotary ≥* Soul
Join Date: Dec 2003
Location: Oregon
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Have you taken your BAC out and cleaned it VERY good. I know mine needs done. Also. Mine pulses up and down and i just unhooked my TPS and it went away. But caused the car to decelerate weird. Also if you unplug it it may either be stuck.. Or not working because the ECU transistor for it friend. Heres a link that might help you. BAC cleaning also BAC ECU fix
12-19-03, 05:54 PM
#3
Today I took off the BAC and cleaned it. I also put 12v too it and it clicks and I can see the solinoid move. Also checked the voltage across a 10k ohm resistor in the BAC plug and it checked at 8.1 volts DC. And just to make sure the ECU was good I swaped it out with a known good one from my other TII. I also replaced the TPS with a brand new unit.
Still doing the same thing.
Any other ideas out there?????????????
Still doing the same thing.
Any other ideas out there?????????????
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