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1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 11:36 am
by mopwrforme
1994 Bonneville ssei 3.8L supercharged i have low fuel preasure apx. 34psi unplug and cap off the reg. the preasure will go up to specs at this point i was prepared to install a new fuel pump until my gm mech. tells me there is a fuel pump control module i need to bypass to insure its not the cause of the low preasure. after much hunt and peck im having no luck. i can find info on 96 and newer but nothing on this 94.question being is it equiped and if so where is it at. yes i did ck. in the 96 model and newer location and found nothing.

thanks again

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 11:51 am
by liljoe
Not seeing anything on the 94, on the later ones, it uses a ballast resistor to drop the voltage to fuel pump under low load conditions, it is located by the coolant/windshield jugs. The relay center has a relay for the low speed operation on the ones that have it. The pressure sems to be doing what it should, if it builds to 45 with the hose off, that says pump building pressure ( does not rule it completely out). What kind of problem are you chasing?

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 12:06 pm
by brianp87
That fuel pressure is borderline. What is the drivability issue? I can help you maybe.

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 12:39 pm
by mopwrforme
p0171 fuel system lean engine will surge. after i blocked off the reg. fuel preasure went too 42 psi i then cleared the memory and its been running fine since. i just didnt want to replace the pump. to find its not the root cause.

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 12:46 pm
by ricmorin
Well it sounds like the fuel pump is capable of making the correct pressure. I'd be leaning towards a regulator. I'd also do a volume test on that pump before I threw one in.

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 12:58 pm
by mopwrforme
great idea this vehical is for resale at this point. ive gottin a bit backed up and will post new findings in a day or two. i will ck volume at that point. thank you for your help too all. ive just this august went on my own, after being a chrysler line tech for 20+ yrs fords and gm products are challenging to say the least. ive got a lot to catch up on but im living the dream. and this forum is great for a shop like mine. that is to say me and tonto thank you all. also i will be on the mopar side to see if i can lend help with what im great at. thanks again 8) 8) 8)

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Tue Dec 07, 2010 1:00 pm
by brianp87
What have you checked. Is the vehicle warming up all the way? Have you checked for vacuum leaks. Is there any signs of fuel in the regulator hose? What about the maf

Re: 1994 Pont SSEi - 3.8L SC Fuel Pressure

Posted: Wed Dec 08, 2010 2:49 am
by steven kiser
it sounds like a regulator issue to me.