1990 L98 Auto Starts, Runs, Gets Rough, Dies
03-12-2015, 06:31 PM
#1
1990 L98 Auto Starts, Runs, Gets Rough, Dies
Hi Everyone,
I've already searched this forum and found some good posts, but more advice and learning is always good... I'm soliciting your help and ideas.
I live in Maryland where it has been very cold. I have to keep my 90 in the driveway (sigh), and it recently started showing a check engine light after a particularly cold spell. C15 is a thermal sensor for the coolant. I cleaned the contacts to that sensor, and the light went away. BUT...
The car will start and run for a bit, then if stopped, won't start again. If left running, it gets progressively rougher, and dies. Then to start requires much cranking with the throttle wide open. Catches and dies. The car is currently not drivable, right on the verge of spring, of course.
Fuel pressure test shows that about 42psi come up with the key on but not engine running. Turn off the key, the pressure drops immediately. Aha.
This suggests a fuel pressure regulator, or one or more injectors leaking. I know there are tests in the FSM to see which, but given the age of the car and mileage, (92K miles) I plan on simply replacing both the FPR and all the injectors while I have it apart.
ADVICE NEEDED - what are the best injectors to use at a reasonable price? Reasonable hopefully being under $300 for all 8 injectors and under $200 would be wonderful if possible (not holding my breath). Also, how to determine what pounds to use...22? 24? more? The injectors in the car appear to be the originals, and without pulling them out I don't know what they are rated. And have read opinions all over the map, including some very expensive alternatives (doesn't make sense for a car that has relatively modest economic value).
So, please help me on choosing injectors. Close to stock but able to tolerate ethanol gas would be fine.
On to the FPR...
I don't see the need for an adjustable FPR, whatever is a replacement for stock seems fine to me. Any advice on that? I'm not looking to modify the car or squeeze more horsepower out. I'm happy with it stock and running right and reliably.
Next, as a part of this process, I plan on changing the in line fuel filter, checking the pump screen, and blowing out the lines with compressed air. And probably replacing the flex hoses.
So, major work ahead. I know this has been addressed before, but if anyone has recently done this and can alert me to special problems or issues that cropped up, tips and tricks, and answer the questions on injector choice and FPR adjustable or not, and a good one to get, I'd really appreciate the help. Thanks in advance...
I've already searched this forum and found some good posts, but more advice and learning is always good... I'm soliciting your help and ideas.
I live in Maryland where it has been very cold. I have to keep my 90 in the driveway (sigh), and it recently started showing a check engine light after a particularly cold spell. C15 is a thermal sensor for the coolant. I cleaned the contacts to that sensor, and the light went away. BUT...
The car will start and run for a bit, then if stopped, won't start again. If left running, it gets progressively rougher, and dies. Then to start requires much cranking with the throttle wide open. Catches and dies. The car is currently not drivable, right on the verge of spring, of course.
Fuel pressure test shows that about 42psi come up with the key on but not engine running. Turn off the key, the pressure drops immediately. Aha.
This suggests a fuel pressure regulator, or one or more injectors leaking. I know there are tests in the FSM to see which, but given the age of the car and mileage, (92K miles) I plan on simply replacing both the FPR and all the injectors while I have it apart.
ADVICE NEEDED - what are the best injectors to use at a reasonable price? Reasonable hopefully being under $300 for all 8 injectors and under $200 would be wonderful if possible (not holding my breath). Also, how to determine what pounds to use...22? 24? more? The injectors in the car appear to be the originals, and without pulling them out I don't know what they are rated. And have read opinions all over the map, including some very expensive alternatives (doesn't make sense for a car that has relatively modest economic value).
So, please help me on choosing injectors. Close to stock but able to tolerate ethanol gas would be fine.
On to the FPR...
I don't see the need for an adjustable FPR, whatever is a replacement for stock seems fine to me. Any advice on that? I'm not looking to modify the car or squeeze more horsepower out. I'm happy with it stock and running right and reliably.
Next, as a part of this process, I plan on changing the in line fuel filter, checking the pump screen, and blowing out the lines with compressed air. And probably replacing the flex hoses.
So, major work ahead. I know this has been addressed before, but if anyone has recently done this and can alert me to special problems or issues that cropped up, tips and tricks, and answer the questions on injector choice and FPR adjustable or not, and a good one to get, I'd really appreciate the help. Thanks in advance...
