Ronin1014

I recently bought a Pontiac Grand Am under the impression it needed a fuel pump. I drove this car home, and can assure you that pump was working. Dude I bought it from cut a giant gaping hole in the floor so I can hear this pump run under the back seat.

Got home and replaced the fuel filter to see if that was responsible for the guys assumption the pump was shot. And while it made a massive difference for the better. Car started and ran fine...for half an hour give or take and I shut it down.

When restarting it it started fine and would idle just fine until I got more than a couple PSI onto the throttle when it just coughed a couple times and quit. Basically, the weight of my boot alone would accelerate the throttle, add in the weight of my foot and it would quit.

It's acting like the throttle positioning sensor is gone out on it but I want another opinion.

What should I be looking at, is the fuel pump really the culprit like this random dude with a wrench thought it was or is the throttle positioning sensor the more likely suspect.

Rftlts

Could be the fuel pressure regulator if it has one

Ronin1014

My brother in law was over the day before yesterday and he was thinking either the throttle position sensor or the pressure regulator. So that is two inclinations to the pressure regulator.

I'm limited on cash but I can probably replace them both. However, I really want to narrow it down as much as possible because this is a short term car. I'm not going to keep it long and don't want to dump unnecessary cash into it. I've already done the fuel filter and the IAT sensor (CEL code) a bunch of cosmetic repair and I still have all the doors to replace and/or rebuild, the dash and the rear seat to replace. So yeah already spent a bit and have more to spend. If it's one thing I want to figure out that one thing and get it fixed. If it's two I'll fix two but...you know how it goes.

Ronin1014

Trying to test the blotty thing and the car is stalling out on start up, I can't get it to run long enough to find out.

Ronin1014

Ok, more details here. When I bought the car it had a fresh PA inspection sticker in it. I noticed the CEL was on, Here in NY state you are allowed two codes on the system as long as they are not direct emissions codes and I am told PA is equally if not more so strict on inspections as NY is. That said figured it would be something related to the problems I was told about and rolled with it.

Upon getting the car home I plugged in the code reader and was provided with some very confusing results. Eight codes, three of them duplicated...was like really. That said we looked them over and took what information we could out of it. Several O2 sensor lean codes, a couple fuel system codes, a misfire as well as one for internal air temp sensor.

I check air cleaner box, brand new filter, no obstructions in the air ways from box to intake so we assume it's the sensor it self and unplug it and start the car, and it ran fine, plug it back in and it stalls out, Replaced. After that was a misfire on cyl 2, pulled the cover off and found the sparkplug basin swimming in oil, we cleaned it out and went looking for the leak. At this point we are still baffled at the shear number of duplicate codes so we cleared the computer and opted to see what comes back. Started the car and drove a mile to the store and back to see what come up.

Well, that short trip brought up two different O2 sensor lean codes, no shock there. At that point in time the car is still exibiting the no start/long crank that was pointing my self and everyone towards fuel pressure regulator and/or throttle pos sensor (it took us 20 min to get out of Save a Lot's parking lot). Get it home and pull the cover to find the oil was coming from the oil pressure switch and replaced it.

Moved on to the fuel system issues and attempting to check the pressure regulator and I could not get it to start...see above post, and it still has not started and ran since then. Now several more days go by trying several times to get it started I figure, well, with as much cranking as we have done on this the computer should have picked something up, sure enough it did. Got a code for the crank pos sensor that we did not have before.

Here in a day or two I should find out if that was the real problem the whole time. This would explain one of the elements that bothered not only my self but also everyone I talked to who had seen and heard it running. Because, when it started and ran, it ran beautify, and quietly like a car that was less than five years old not just short of fifteen.

What bothers me about this is the crank pos sensor did not produce a code until a week after complete failure. Why would this be?

Ronin1014

Another update:

The oils was the result of a popped oil pressure switch which has been replaced. Sadly it seems I can not simply clean the oil out of the plug boots and will now have to replace them before I can go any further.


I got the Crank position sensor changed out, and managed to get back to a long crank start/stall condition. Unfortunately I am still combating the side effects of the oil in the spark plug basin. Can some one confirm this for me, I hear an audible snaping of a spark arc from under the coil cover. Disassembly shows no visible signs of arcing from any of the components, is this in fact a short caused by the oil laced boots? Is there any temporary hold over so I can run this pig long enough to check other components until I get the replacement boots.