Why does my 1993 Chevy TBI stall at idle?
Timing is steady and not jumping all over. It is a fuel issue. The only code that ever sets is a P044, lean exhaust, and the exhaust is really lean. We have swapped PCM/PROM with a same year Suburban, no change. Both vehicles run the same as this did using the other’s PCM.
Can a bad throttle position sensor cause stalling?
Similarly, if your engine struggles to idle efficiently, it could also be a result of a damaged throttle position sensor. Stalling, surging, or hesitating while idling all can be caused by this unassuming sensor. The best way to determine if these issues are caused by your throttle position sensor is to go to the source.
What should fuel pressure be on 1993 Chevy TBI?
Verify there is 18-20 of fuel pressure when you dead head the fuel pump. If low, verify there is good power and ground to the fuel pump and that the fuel filter is clear. Also, make sure that the MAP sensor vacuum port in the throttle body is not restricted.
Timing is steady and not jumping all over. It is a fuel issue. The only code that ever sets is a P044, lean exhaust, and the exhaust is really lean. We have swapped PCM/PROM with a same year Suburban, no change. Both vehicles run the same as this did using the other’s PCM.
Similarly, if your engine struggles to idle efficiently, it could also be a result of a damaged throttle position sensor. Stalling, surging, or hesitating while idling all can be caused by this unassuming sensor. The best way to determine if these issues are caused by your throttle position sensor is to go to the source.
How does a GM throttle body relearn procedure?
A motor and gear reduction set inside the throttle body opens and closes the throttle plate to accomplish your request. Over time, carbon buildup can accumulate around the throttle plate, changing it’s “home” position. If the buildup occurs gradually, the PCM “learns” the new home position.
Verify there is 18-20 of fuel pressure when you dead head the fuel pump. If low, verify there is good power and ground to the fuel pump and that the fuel filter is clear. Also, make sure that the MAP sensor vacuum port in the throttle body is not restricted.
How many MV does a 1993 Chevy TBI have?
Even now it seems on the lean side, but will for a while have one 02 crosscount before the 20 second lean PCM clock expires throwing it into open loop. The 02 MV hot will frequently hang down around 56 MV to 156 MV and never cross over to rich for a long time.
Why is vacuum plugged off on 1993 Chevy TBI?
EGR vacuum is plugged off because EGR diaphram has a leak. I pulled EGR to inspect days ago, and pintle spring has good tension holding valve completely closed, not leaking at all. I know the EGR will richen mixture a little on a hot engine, but that is not the problem.
Even now it seems on the lean side, but will for a while have one 02 crosscount before the 20 second lean PCM clock expires throwing it into open loop. The 02 MV hot will frequently hang down around 56 MV to 156 MV and never cross over to rich for a long time.
Where is the idle button on a GM TBI?
The “A” and “B” terminals are located on the top right of the connector. Unplug the IAC valve located on the passenger side, rear of the throttle body. Start the engine. Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier.