Pontiac Repair: 92 SUNBIRD 3.1, lean condition, scan tool

Question
QUESTION: IT IDLES FINE UNTIL FUEL PRESSURE GOES OVER 40 PSI THEN IT STARTS TO CUT OUT AND IF YOU GIVE IT GAS IT DIES.IS IT TO MUCH PRESSURE OR AM I LOOKING IN THE WRONG SPOT THERE ARE NO ENGINE CODES .IT RAN GREAT THEN NEXT DAY THIS IT ONLY HAS 87000 MILES

ANSWER: Hi Mike:

That sounds a bit high I think that engine runs more at like 35-38 psi. You could have a issue where you don't have enough fuel volume from the pump the pressure could be okay but not enough volume to keep the engine running at higher speeds. If you have a scan tool look at the short term fuel trim and see what what it does when you run the engine speed up if it's adding fuel that would be a indication of a lean condition and vise versa for a rich condition. Good luck :}


---------- FOLLOW-UP ----------

QUESTION: what do you mean short term fuel trim


Answer
what I mean is up to the minute fuel delivery. on a scan tool you can see how the engine computer is driving the fuel delivery into the engine. short term is right now the way the engine is being run. that is a good indication of what's going on. if while running that number spikes up or down will give you a direction is which to look for the fuel delivery problem. I hope I didn't confuse you more....