1990 Grand Prix Gremlins

start

#1

i have a 90 gran prix that is drivin me nuts

it started with going to store and coming out and wouldnt start unless sat for hour or so

eventually died going down road with same results

i have replaced computer ,the prom,crank sensor ,coil pack and module,air temp sensor and one othersensor that i cant remember the name of

i have had two different peaple put scanner on the last a reputable shop

after several hundred dollars and alot of frustration the only answer i have is you need to take somewhere else do not know what is wrong. It still starts right up when cold runs alittle rough and throttle response is relly touchy with hesitation

once warms up i can start it right up after shutting off but if sets for more than 15miutes it wont start until cools down again HELP i am goin nuts and broke


#2

i guess i should have given more info
v-6…3.1 engine …auto tranny… fuel injected
does not pull any codes on dash when checked


#3

So far you have only focused on spark. What makes you think it is a spark problem and not a fuel problem? At that age it could be a fuel pump going bad, bad fuel pressure regulator, fuel pump relay, connection to the pump, pump wiring, etc.


#4

new filter,pump is 80 pounds ,40 lbs at rail, good spark,when wont start i tested the injector wire that i could access to se if getting signal and it only pulseed once should have signal each time it is to deliver feul…right
it is a feul problem


#5

If the throttle response is touchy, that could be caused by the throttle position sensor (tps). Check the output voltage (back probe) of the tps. Move the throttle slowly while observing the voltage. If you see voltage spikes, or dropouts, the tps is defective.
“It won’t restart after 15 minuets shutdown” could be a fuel injector(s) leaking after shut down. This would flood the engine. To start a flooded engine, hold the gas pedal to the floor while cranking the engine. As the engine starts, ease up on the gas pedal.
You can check for a fuel system which won’t hold fuel pressure by putting a fuel pressure test gage on it. The fuel pressure should hold for 30 minuets after engine shutdown. If it doesn’t, the injector(s), or fuel pressure regulator is leaking.