A little info:
1995 Classic with 3.9 built out of 4.0 block.
After my timing chain replacement, I put the engine together and ran it for about 3k miles now. It runs well, but it drinks gas like there's no tomorrow, and the idle sucks. It had a classic surging idle symptom - when the engine warmed up, it would go between 300 and 1000 rpm, and eventually stall.
The timing is at 8-10 deg BTDC, the TPS at closed throttle reads .32V (and goes up/down when it should), the MAF at idle reads 1.5V (and goes up and down when it should).
Both coolant and fuel temperature sensors work and read reasonable values.
Both O2 sensors work.
The IAC solenoid works and its operation can be observed.
There are no vacuum leaks in/around the intake - the idle stabilizes when I pull the PCV breather hose off- anywhere at the tee.
Fuel pressure regulator is tested and operational, pressure at the rail is steady at 35psi.
Yesterday I screwed around with base idle screw on the throttle body, and got it to run stable, but now the short-term fuel trims are pegged at 100% and the IAC solenoid position is also shown at 100%. The exhaust definitely smells rich.
Here's a screen shot of RS-RV8 app:
Any suggestions?
1995 Classic with 3.9 built out of 4.0 block.
After my timing chain replacement, I put the engine together and ran it for about 3k miles now. It runs well, but it drinks gas like there's no tomorrow, and the idle sucks. It had a classic surging idle symptom - when the engine warmed up, it would go between 300 and 1000 rpm, and eventually stall.
The timing is at 8-10 deg BTDC, the TPS at closed throttle reads .32V (and goes up/down when it should), the MAF at idle reads 1.5V (and goes up and down when it should).
Both coolant and fuel temperature sensors work and read reasonable values.
Both O2 sensors work.
The IAC solenoid works and its operation can be observed.
There are no vacuum leaks in/around the intake - the idle stabilizes when I pull the PCV breather hose off- anywhere at the tee.
Fuel pressure regulator is tested and operational, pressure at the rail is steady at 35psi.
Yesterday I screwed around with base idle screw on the throttle body, and got it to run stable, but now the short-term fuel trims are pegged at 100% and the IAC solenoid position is also shown at 100%. The exhaust definitely smells rich.
Here's a screen shot of RS-RV8 app:
Any suggestions?