1989 Buick LaSabre

I have a 1989 Buick LaSabre that is having some problems and no mechanic seems to be able to figure it out. After 4 computer items totally $1,800.00 since March, the same problem started again yesterday. I am driving through the hills to town and the dashboard lights all come on and my engine cuts out. I stop, put in park and restart and take off again. As soon as I am on the highway, car runs fine. It has something to do with the fuel system I believe because once it cuts out the car smells like lots of gas but after it starts back up (and it does every time) the smell goes away. I REALLY REALLY would appreciate some input as to what could be the problem. Thanks so much everyone.

I have a 1989 Buick LaSabre that is having some problems and no mechanic seems to be able to figure it out. After 4 computer items totally $1,800.00 since March, the same problem started again yesterday. I am driving through the hills to town and the dashboard lights all come on and my engine cuts out. I stop, put in park and restart and take off again. As soon as I am on the highway, car runs fine. It has something to do with the fuel system I believe because once it cuts out the car smells like lots of gas but after it starts back up (and it does every time) the smell goes away. I REALLY REALLY would appreciate some input as to what could be the problem. Thanks so much everyone.

I think the main problem here is that you really haven’t had your malfunction addressed by a real mechanic. Stay away from the dealership and any chain repair shops. Find a good independent mechanic and you will be money ahead. 4 computer items totaling $1800? Really? Your malfunction appears to be fuel related (fuel pump or fuel injectors) so it’s fairly simple to diagnose.

My first guess would be the fuel pump relay has some faulty contacts and is a pretty common issue. If you have already paid $1,800 dollars to try and fix this trouble you should find another shop or the shop that has been working on this same problem owes you some free service time.

I have stayed away from car dealerships and chain repair shops and always go with independent shops. The mechanic here in Warsaw replaced the throttle intake module (I think that is what it was called) in May and it has run great ever since until yesterday. That fix was only $78.00. The cheapest and thought it was fixed. It is not the fuel pump as I had that looked at. One computer part was $800.00, $811 and 180.00. Just crazy to still be having this problem. Any more input would be appreciated. Thanks so much

I agree with @missileman

I suspect the guys you’ve been dealing with have no service manual, no patience and limited diagnostic skills.

Unfortunately most work was done in Florida. In Missouri I’ve only spent the $280.00. Fuel pump relay, I’ll have to look into this and find a new mechanic. Thanks.

To be fair, intermittent problems like this can be a real bear to pin down at times. A lot of times the shop just has to guess at the solution since the car is most likely working okay while they have it. Replacing the simple, cheapest, and most logical things for the trouble is usually how it goes. If that doesn’t work then you move on to the next thing. At times the trouble isn’t with a replaceable part and the fault is really with a wire connection somewhere. So replacing parts just becomes a waste of time and money.

Thanks Cougar.

Good luck. I had the same problem with my 89 Riv. Finally got $500 in trade. I swapped computer, fuel relay, new pump, pump wiring, ignition switch, crank sensor, etc. At the several shops several times and no solution. A word of caution though, don’t spend a lot of money on it. I got a spare computer from the junk yard for $25. No need to pay $800. Never had a computer problem but having a spare enables ruling that out. One guy on here also had the same issue and finally figured out it was the EGR valve so may want to try that. Just because it smells of fuel doesn’t mean its a fuel issue. Unless of course you have a bad fuel pressure regulator. You should just get a pressure tester on it to find out.

Thank you bing and all others for giving me some ideas to present to the new mechanic, so I don’t look so silly because I really don’t know that much about vehicles. I may know a thing or two after this though. TX! Again.

Car ran great yesterday and today. We’ll see what happens next. Not sure what to do because when it isn’t acting up, can’t have anyone look at it. Hope nothing bad happens. Thanks again all.

The fuel pump relay has to handle the current needed by the fuel pump motor. The relay contacts can wear out over time and become either intermittent or just totally bad. When the relay contacts are intermittent they can cause this very issue you are having. The contacts heat up while the car is running due to the contact resistance an current load and can cause the pump to stop running when the voltage drop across the contacts gets to be too much. Power to the pump drops too low to drive the pump motor and the engine dies. You then restart the car and the contacts of the relay reconnect and are okay again, at least for a while until the same thing happens over again. The relay may not really be the issue here but it sure should have been on the top of the list for the possible trouble. Since it is real easy to change it out and not expensive I would do that just to see if that helps. Since the car seems to just start right up again when the trouble occurs at least you don’t have to worry about getting stranded somewhere.

Like I mentioned on another post, a second source of power is provided to the fuel pump through the oil pressure sensor. Once there is oil pressure, either from running or extended cranking, power is supplied to the pump and by-passes the relay. You can remove the relay entirely and the car will continue to run if the oil pressure switch is good. So at any rate, because of this, I have a hard time focusing too much on the relay, particularly if it stalls while running. You could have no relay and it still wouldn’t stall.

Now I’ve had connection problems at the pump, wiring problems from the pump to the computer, and bad Delco pumps out of the box. Even had a new pump fail within one day of a year with a new pump. Life has become much more pleasant since I junked the car.

Thanks to you both.

I understand what you are saying about the oil pressure switch @Bing. If this vehicle uses the same circuit design then instead of the fuel pump relay being suspect the pressure switch would then be the suspect for the problem. By placing a jumper across the contacts of the switch it would bypass it. You do lose the protection for the engine by doing that but for a short test period it should be ok.

I don’t wanna beat a dead horse, but I’ve just gone the route of relay and pressure switch a few rounds with no success. I never had a bad one of either. The way to test the pressure switch is to just pull the relay when the engine is running. If it stays running, the switch is ok. The relay can be tested by switch on, with a test light at the prime connection. If the test light comes on when the switch is turned on, the relay is good. If you have power at the prime connection but the pump doesn’t run, its either the pump, wiring to it, or connection. Even with either a bad relay or a bad pressure switch, the engine should still run but after extended cranking. If both are bad you are out of luck.

I had that EXACT same problem with my 1995 Buick LeSabre. Car would run fine, then cut out on the highway, and I’d have to put it in neutral and attempt to restart it while running or coast to a stop and attempt to restart. This was not safe for obvoius reasons. The problem was intermittent but enough of a show stopper on any long trip.

Well, after having had various sensors replaced. O2 sensor, Mass Air Flow Sensor, Crankshaft sensor and even the computer - TWICE, the probably still wasn’t fixed.

Turns out it was the computer after all. I ended up buying a refurbished computer from the dealer which fixed the problem. The two computers I bought from parts places / junkyards did NOT work.

All told I was out about $3200 in repairs and diagnostics. If my car was a high mileage one, it would have long been a trip to the junkyard but I only have about 100,000 miles on it, and I figure it’s got a lot of life still left since my last car was a 1992 Buick LeSabre that had over 220,000 miles before it finally quit.

Hope this helps.

That’s some very good info @Tigerboy. I just wonder about one thing. Usually problems with ECUs aren’t intermittent, just bad all the time. As far as I know at least. It just makes me wonder if the problem was really due to a faulty connection somewhere and by replacing the ECU it corrected the wiring fault somehow. Intermittent problems like this can be such a pain to find. You very well may have the right answer here though and replacing the ECU with a known good one may solve the issue. Replacing it at least would eliminate that part of the equation and a replacement shouldn’t cost a large amount of money.