1G stalling problem

[90laserdsm]

i just got my car running. rebuilt block and built head. i went to take it for the first drive to break it in and when i pushed the clutch in it stalled. it dropped to about 500 rpms then stalled. it doesnt do this at idle. i put a different maf on. i checked the throttle position sensor and the closed throttle position switch. i checked for major vacuum leaks but there still might be a leak. any ideas?

 

[DSM1G90]

Try to reset the IAC motor. After resetting the IAC motor, adjust the BISS screw to the 750rpm requirement.

Goto this page: 1G BISS Adjustment on how to do the steps in resetting the IAC then the BISS.

If the above test fails, IAC might have to be replaced. And IAC's are more complex to replace in a '90 setup since it sits at a different angle than the 91's and beyond.

Trust me, been there and done that with my '90 Laser.

The IAC prevents stallouts when the clutch is dropped.

Good luck-DSM

 

[90laserdsm]

okay i will try that tomorrow when i get a chance. thanks for your help

i also have bc 272 cams. could they possibly be causing it to stall? i think i have the idle set somewhere between 800 and 1000 rpms. should i try to put it a little higher?

 

[JamesH3]

Check the iac, and biss like stated

 

[DSM1G90]

With bigger cams, more air is pulled in causing a lean idle mixture making the motor to have a rough idle..and why you're running a slightly higher idle RPM...

Still, do the IAC reset then do the BISS, but turn the BISS screw to give you that higher idle speed and don't adjust the cable or idle stop screw to get your idle up higher. If already did such, return them to were they were, otherwise you'll never get the correct adjustments needed.

In fact, make sure that you got 1/8" cable slack between gas pedal and throttle plate cable connector so the throttle plate is fully closed before doing the IAC and BISS screw tasks.

Good luck-DSM