1989 Buick Century Fuel System Problems

MOBLEYJ

MEMBER
1989 BUICK CENTURY

Engine Performance problem
1989 Buick Century 6 cyl Front Wheel Drive Automatic

I am having an issue where I am driving and the motor will just cut out as if just shut off. When the problem began to manifest it's self I would be driving down the road and it would act as if the transmission was slipping. (I later found that this was the engine cutting out and then restarting on its own.) It has now gotten to the point where when it cuts out the car will die and it will not start again. However if just let to sit for several hours, you can go and start the car just fine again. As time goes on and I can not figure out the problem, I am getting less and less miles before the car dies again. Now I can only run the car for around 10 miles (20 minuets, city driving) before it dies and will not start. I attributed this to a clogged fuel filter and so I changed it out. However, within the first 20 minuets of driving after the filter change I sadly found that the problem is still there and it was not related to the fuel filter.

On several occasions, while the car will not start, I have verified that there is spark at the spark plugs. I can also hear the fuel pump kick in, build pressure and quit pumping when the system is pressurized. For this reason I do not think that it is the fuel pump. I am leaning to the idea that there is something going on with the fuel injection system. I have no idea how to troubleshoot this. If it is the fuel injection system, then it is not just one injector that is being affected but ALL of them at the same time because I believe that there is NO fuel getting to the motor when I can not start the car. I am also not sure how to get the troublecodes from my car ether.

What sensors/components do I need to look at? What could be causeing this issue. Please help me figure out the problem here.

5 Replies

SATURNTECH9

MECHANIC
30,870 POSTS

First of all thank you so much for your donation. Well we know you have spark when it doesn't start. Now we need to check fuel pressure when it doesn't start auto zone rent's fuel pressure gauge's rent one and when it doesn't start check and see what the fuel pressure is. Also rent a noid light if you can to check the pcm injector pluses so we can rule that out also. Also have you checked for code's?

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Thursday, July 8th, 2010 AT 12:19 AM

MOBLEYJ

MEMBER
3 POSTS

Ok, in reguards to the fuel system pressure, I was looking at the electrical diagrams and noticed that there is a pressure cutoff switch tied into the fuel pump. I can hear the fuel pump kick in and after a couple of seconds shut off again. Am I safe to assume that this indicates that the pressure in the system is ok? This happens even when the car will not start. I currently do not have access to a pressure guage and so if I do not have to hunt one down I would rather not. (If it becomes absolutly necessecary I will though.)

I have a noid tester now, but I will need to wait until the car dies again to test the injector pulses (Most likely not far down the road.)

I pulled the trouble codes today and the only code that is showing up is code 22 - TPS sensor voltage low. Would a failing TPS sensor also create the symptoms that I am having? The car runs GREAT until it starts to cut out. I have not noticed any degrading fuel performance such as running rich or lean, just outright cutting out.

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Thursday, July 8th, 2010 AT 12:54 PM

SATURNTECH9

MECHANIC
30,870 POSTS

The fuel pump running for 2 second's and shutting off is the car priming the injectors. It doesn't mean we can assume that you have enough pressure to start and run the car that's why I was asking you to rent a fuel pressure gauge to see if we did. The code 22 is a good starting point if it was failing it could cause a lot of different problem's. What size engine do you have so I can get you the code 22 trouble tree.

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Thursday, July 8th, 2010 AT 1:59 PM

MOBLEYJ

MEMBER
3 POSTS

Ok it will be a couple of days before I can rent a pressure guage but I will do so and let you know what I find out there.

I ran the noid light test and everything appears to be good. While the car would not start I hooked it up and there does appear to be a pulse signal being sent to the injectors.

I have a 3300 (I believe this stands for 3.3L) 6-Cylinder Engine.

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Thursday, July 8th, 2010 AT 9:38 PM

SATURNTECH9

MECHANIC
30,870 POSTS

Sound's good let me know when you get the fuel pressure when it doesn't start. Also do you still have spark when it doesn't start?I emailed you the trouble tree for your code 22.