1991 olds 88 oil light intermediatly
#1
1991 olds 88 oil light intermediatly
Hello, I'm new to the forum and am hopelessly looking for answers. This is a long story but I'll try to make it short. The olds ran flawlessly until one day it stuttered and died when parking. Oil light flashed and it died. I changed all fluids just in case. Car would flash oil light and intermediatly die from time to time. One day it died and wouldn't start again. I replaced ecm coil pack, plug and wires just to start it. Thought it fixed the problem but it didn't. I just replaced the crankshaft position sensor and cleaned maf and it still does it. Now it'* mostly when it'* under load and I'm coming to a stop and rpms lower. Any help would
be appreciated.
be appreciated.
#2
Senior Member
Well, for one thing which oil light?.....not sure which cluster you have....all gages or minimum with idiot lights....
Also, there are two possible oil lights, one for the level sensor if it has one, and the other for pressure....if it'* the level sensor light but the level is ok, then it'* the sensor or the wiring, and will not cause a stall/no start.....if it'* the pressure light, then it could be the pressure sender or wiring.....attaching a manual gage would determine if pressure is the problem....
But sometimes, the oil light can flash just from stalling......oil level is ok, and no knocking sound from engine?
Since you say you have more of a problem under load, I am thinking secondary ignition....you say you replaces plugs and wires...hope you used OEM plugs....
You replaced the Coil pack? Is this one coil with 6 terminals(Magnavox) or does it have 3 individual coils with two terminals apiece?
If this is a Magnavox coil, was it new or used? These coil packs were known for problems...
What you should do is a spark output test, with a spark tester attached to the end of each ignition wire one at a time, to check and see if you have good spark from all terminals.....if you got a used coil, that could be bad.....otherwise, since you replaced the Crank sensor, properly I hope( I think the one for this year is adjustable), the other possibility is the ICM......
Other possibility is the MAF.....if the car will not start, disconnect it and try to start...if it starts, you found your problem....
Another possibility is the fuel pressure regulator leaking, sucking fuel into the intake via the vac line on it....
And still another is fuel pressure...last time the fuel filter was replaced? Ever check the pressure at the fuel rail?
And has the vehicle been scanned for codes? You can read codes without a code reader/scan tool by Grounding A to B in the ALDL connector and turning key to run position(don't start car)....check engine light will flash "12" three times, then it will flash any codes in the car after that, three times....when it flashes "12" again(one flash, pause, 2 flashes), that is the end of the codes....If it only flashes "12", there are no codes....
Also, there are two possible oil lights, one for the level sensor if it has one, and the other for pressure....if it'* the level sensor light but the level is ok, then it'* the sensor or the wiring, and will not cause a stall/no start.....if it'* the pressure light, then it could be the pressure sender or wiring.....attaching a manual gage would determine if pressure is the problem....
But sometimes, the oil light can flash just from stalling......oil level is ok, and no knocking sound from engine?
Since you say you have more of a problem under load, I am thinking secondary ignition....you say you replaces plugs and wires...hope you used OEM plugs....
You replaced the Coil pack? Is this one coil with 6 terminals(Magnavox) or does it have 3 individual coils with two terminals apiece?
If this is a Magnavox coil, was it new or used? These coil packs were known for problems...
What you should do is a spark output test, with a spark tester attached to the end of each ignition wire one at a time, to check and see if you have good spark from all terminals.....if you got a used coil, that could be bad.....otherwise, since you replaced the Crank sensor, properly I hope( I think the one for this year is adjustable), the other possibility is the ICM......
Other possibility is the MAF.....if the car will not start, disconnect it and try to start...if it starts, you found your problem....
Another possibility is the fuel pressure regulator leaking, sucking fuel into the intake via the vac line on it....
And still another is fuel pressure...last time the fuel filter was replaced? Ever check the pressure at the fuel rail?
And has the vehicle been scanned for codes? You can read codes without a code reader/scan tool by Grounding A to B in the ALDL connector and turning key to run position(don't start car)....check engine light will flash "12" three times, then it will flash any codes in the car after that, three times....when it flashes "12" again(one flash, pause, 2 flashes), that is the end of the codes....If it only flashes "12", there are no codes....
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rjolly87 (11-22-2017)
#3
Retired
I thought I seen something somewhere that on older engines, the fuel pump circuit is turned on via the oil pressure SWITCH. If oil pressure gets below a preset level, the pump shuts off, thusly saving the engine. You should get onto Alldata and look up schematics for your vehicle and verify.
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Retired Administrator
#4
Senior Member
Mike, if I remember that circuit right, the oil pressure switch was put in parallel with the f/p relay....it was a backup, to the relay......if for some reason, the relay or it'* circuit failed, the car would not start...however with the oil pressure switch in parallel with the relay circuit, the car would crank, and as soon as oil pressure built up to about 4 psi, the oil pressure switch would close and power to the fuel pump(a good indicator or a bad f/p relay circuit, was a long extended crank, until oil pressure built up).....it did not work in reverse though.....if the fuel pump circuit was ok, but oil pressure dropped below 4 psi, the oil pressure switch would open, but the engine would continue to run, since both circuits were in parallel...
#5
Senior Member
True Car Nut
Tech II has given most suggestions that I would. The only other thing I would recommend checking would be to rule out the possibility of any exhaust restrictions.
A broken/plugged up catalytic converter can very easily cause problems, problems that can easily be apparent when running a while, and aggravated by a heavy load.
A broken/plugged up catalytic converter can very easily cause problems, problems that can easily be apparent when running a while, and aggravated by a heavy load.
#6
Senior Member
True Car Nut
I thought I seen something somewhere that on older engines, the fuel pump circuit is turned on via the oil pressure SWITCH. If oil pressure gets below a preset level, the pump shuts off, thusly saving the engine. You should get onto Alldata and look up schematics for your vehicle and verify.
Mike, if I remember that circuit right, the oil pressure switch was put in parallel with the f/p relay....it was a backup, to the relay......if for some reason, the relay or it'* circuit failed, the car would not start...however with the oil pressure switch in parallel with the relay circuit, the car would crank, and as soon as oil pressure built up to about 4 psi, the oil pressure switch would close and power to the fuel pump(a good indicator or a bad f/p relay circuit, was a long extended crank, until oil pressure built up).....it did not work in reverse though.....if the fuel pump circuit was ok, but oil pressure dropped below 4 psi, the oil pressure switch would open, but the engine would continue to run, since both circuits were in parallel...
#7
Senior Member
True Car Nut
Hello, I'm new to the forum and am hopelessly looking for answers. This is a long story but I'll try to make it short. The olds ran flawlessly until one day it stuttered and died when parking. Oil light flashed and it died. I changed all fluids just in case. Car would flash oil light and intermediatly die from time to time. One day it died and wouldn't start again. I replaced ecm coil pack, plug and wires just to start it. Thought it fixed the problem but it didn't. I just replaced the crankshaft position sensor and cleaned maf and it still does it. Now it'* mostly when it'* under load and I'm coming to a stop and rpms lower. Any help would
be appreciated.
be appreciated.
Is the oil light coming on just as or after it stalls or before it stalls?
How many miles on this car?
Where in the world does this car live?
Does it have this problem when the drivetrain is cold (like cold start couple-minute drive) or warm (like more than ten minutes driving)?
I'm thinking Idle Air Control valve sticking/failed/plugged with junk/etc.
Try this: when it would normally stall, give it a little throttle, like very little. Does it seem to be mostly happy and/or can hold something near normal idle speed of 600-800RPM?
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