Car dying

gsipe2016

I have a 1997 Pontiac Bonneville and when im sitting still my oil pressure drops almost in to the red. Also when i just barely tap the gas like in a drive through to move forward my car will die but starts right back up. Can anyone help me out here?

imidazol97

If you don't get stalling any other time, I don't suspect the crankshaft position sensor.

I would take the MAF (mass air flow sensor) off and use a spray meant to clean electronic
sensors. It contains two fine wires that are cooled by the air going over them. They collect
dirt particles on them. The MAF is held on by two security torx screws--they have the little
dimple in the middle so it takes a special bit on the end of the tool.

I would also think about having the intake cleaned around the butterfly throttle plate.
That area gets gunked up with blowback gases from the crankcase when the car is
turned off. The layer of gunk affects the air that bleeds past the throttle plate when it
moves from dead off at idle to slightly off idle. Does the throttle ever feel like it
sticks the first time you move it after the car has sat and is totally cold overnight?

Along that line too, the IAC (idle air control valve) is on the throttle area with the
MAF and it bleeds air past it's nozzle. The IAC is adjusting constantly to bleed the
right amount of air through; if the throttle plate is very gunked up,
the IAC may not keep up quick enough, hence the stall.
The gunk inside the throttle where its nozzle
sits can affect it as well. So it might help to be taken off and cleaned carefully so
that chemical doesn't go down into the valve's working parts.

gsipe2016

I'll look into all of that i really appreciate it. Also the throttle does seem to stick when i first take off in the morning. when its cold out.

imidazol97

gsipe2016 said:

I'll look into all of that i really appreciate it. Also the throttle does seem to stick when i first take off in the morning. when its cold out.

This video shows cleaning a throttle body off the car. It can be done on the car. Requires careful
work to remove honeycomb. Not for beginners.

https://www.youtube.com/watch?v=ST0qUTAztPk

As for the oil pressure, if the car is over 175K miles, that's a likely problem. Be sure
to use 10W 30 weight oil and I'd recommend getting the high mileage oil--not the
expensive synthetic that runs a lot of miles but the oil that's meant for cars over
70K miles or so. The oil is basically regular 10W30 oil that runs toward the
higher end of the viscosity range. It also has some materials to swell seals
since the 3800 is prone to seeping between the head and block.

I use Mobile 10W30 blue 5 quart jug at Walmart.