Last post on Sep 21, 2013 at 10:39 AM
You are in the Buick Regal
What is this discussion about?
Buick Regal, Sedan
#3422 of 3508 Re: 2000 Buick Regal Super Charged GS 3600 [bsamstag]
Apr 14, 2009 (2:18 pm)
Check connections at ISC and check the fuel pump pressure. Drive with a gauge on the windshield until it stalls. But fuel problems tend to happen after the car and fuel heat up from pumping through the system. That's not what you're describing.
MAF sensors can also cause trouble. Some people suggest tapping on the body of it with a screwdriver handle and if the car changes speed or misses, you may have found the problem. A good test is substituting a known good one from another vehicle since many are the same part number.
ALSO check the EGR. In fact, disconnect the EGR, will set a code, and drive it a while when it's in the shutting off mood. I've seen reports of sticking EGRs. Must have been a bad supplier. If the EGR sticks open the car gets too must exhaust gas back through and runs rough. At high speed a sticking EGR may not make a difference.
I'm not sure what you mean by low speed idle sensor. I suspect it's the IAC, idle air control, that lets air past the butterfly to control the idle speed. Did they clean the throttle body? It gets covered with a black goop and may lead to the butterfly sticking when you first start the car; you have to press hard on the accelerator to get it to open. Many cars have this problem. It's cleaned with with solvents. Often the IAC gets gooped up too. Cars with lots of short trips and starts may do this more.
I'm betting on the EGR, if I were a betting man. But I do wish you luck in diagnosing. It really takes a TEch II or scan tool that reads out in real time connected while driving to see what parameter went wrong when the car stalls. Your local mechanic may not have that tool. The dealer does.
#3423 of 3508 Re: 2000 Buick Regal Super Charged GS 3600 [imidazol97]
Apr 14, 2009 (3:56 pm)
I had a similar problem with my 2001 Regal LS stalling without warning while idling or even when slowing down for a stop. Went through everything including replacing the crank sensor. No error codes. Took it to the dealer and they replaced the fuel pressure regulator which they said was leaking. Now it wasn't leaking gas, but maybe an internal leak was the problem. Fuel pressure was always good even when it stalled. Once the fuel pressure regulator was replaced the problem went away. It was also hard stating and you had to crank a bit to get it going, especially if it was warm. On very cool mornings it would start right up. Hope this will solve your problem.
#3424 of 3508 Re: 2000 Buick Regal Super Charged GS 3600 [k8yse]
Apr 15, 2009 (3:49 am)
Another good point. The FPRs seem to have been a problem. Must be a bad supplier or design.
There are several things to try to check to find a problem like he's having. The FPR leaks fuel through itself into the vacuum line that controls it.
When the car has been running and shut down, pull off the vacuum line and see if there's raw fuel in the line. There shouldn't be.
Note that occasionally the FPR failure can cause fuel ignition inside the upper intake manifold which splits it with the pressure (explosion like a backfire). There were recalls on some years for the FPR.
#3425 of 3508 Re: 2000 Buick Regal Super Charged GS 3600 [imidazol97]
Apr 15, 2009 (11:47 am)
Thank you for that information, which has not been mentioned in any of the many forums where I've posted my Buick Regal Stalling problem. My mechanic was diagnosing an identical problem with a Buick Park Avenue, and it was resolved by replacing the FPR. Unfortunately , mine passed the "Smell Test", indicating no leakage, so the errant Regal with the penchant for stalling in an unpredictable manner still haunts my driving habits.
#3426 of 3508 Re: 2000 Buick Regal Super Charged GS 3600 [k8yse]
Apr 15, 2009 (12:03 pm)
I'm curious how the dealer determined the FPR was leaking. The Family Financial Committee (aka: my wife) thinks I've sunk enough money trying to solve the Regal problem, but I think I'm ready to try "one more thing" if there's a chance the darn Buick would become reliable. I cannot afford to buy something to replace it. My mechanic quotes it at $115.00 with about $75.00 labor. I'm into repair approaching $500, and wonder if another $200 might work.
#3427 of 3508 Re: 2000 Buick Regal Super Charged GS 3600 [bsamstag]
Apr 15, 2009 (12:54 pm)
I think your problem is your mechanic more than your car.
For a car to run there has to be air, fuel and spark. When a car won't run, we check for spark using at worst a screwdriver stuck in a plug wire and held close to a ground on the motor while the car is cranked. If no spark then troubleshoot ignition.
If a car won't start we check for fuel. The fuel pressure can be checked at the fuel rail (on the FPR? by screwing on a gauge). The injector can be checked by unsnapping the electrical connection and putting in the leads from a 194 or 197 lightbulb used in running lights on cars. If it clinks, the injectors are being opened by the electronics on the car.
If the car is running poorly a Tech II computer is connected to see which parameter is askew and then find what causes that which can be something far removed from that symptom.
#3428 of 3508 Re: 2000 Buick Regal LS
Apr 15, 2009 (1:38 pm)
The Regal starts and runs nicely, so it has air, fuel and spark. The problem occurs when the Regal is decelerating, sometimes when I am applying the brakes, but the motor has stopped when coasting to a stop. The stoppage could occur within a few blocks, or after the car has been driven for an hour or more around town. It runs great at freeway speeds.
My mechanic says he cannot fix the problem unless he can make it happen in his shop with diagnostic tools connected. Unfortunately, it rarely fails off the road, sitting stationary with the motor running. Once, it ran long enough in his shop without failing until it ran out of fuel.
Although the Fuel Pressure Regulator passed the "smell test," indicating that there was no fuel leakage, another Buick owner said that replacement of the FPR solved his problem. The question is: Do I spend another $200 for another Shot in the Dark, and hope it solves the problem?
#3429 of 3508 Re: 2000 Buick Regal LS [bsamstag]
Apr 15, 2009 (1:47 pm)
The FPR is about $70 and $80 for Delco units without shipping on rockauto.com. I don't know which is correct for your application.
But, the mechanic needs to drive the car with a Tech II attached so that when it is coming to a stop the Tech II records what changed at the time of the stalling. The computer used by the dealer is portable.
You could be chasing a poor connection in fuel pump wires going under through the car to the pump. It loses contact under certain deceleration forces.
You could be chasing a vacuum leak caused by poor tubing around the upper intake on the car or the upper intake itself leaking around the seal or a crack but only under certain conditions (but you've never mentioned erratic idle speed or high idle speed--I'm using this as an elusive, hard-to-find problem that others have ended up finding).
You could have an EGR sticking open as the engine slows down causing a stall. Have you disconnected the EGr and driven the car for a while?
Has the MAF been cleaned with solvent? Has another one been put in temporarily to see if that cures the problem.
Driving with a Tech II attached will catch either the direct cause (power to fuel pump failed briefly, e.g.) or a symptom of what is causing the stall.
Does the car have double positive battery cables? Has the plastic between them been opened and the connection inside checked as well as down into the cable? Does anything else electrical happen when the motor dies?
That's why I'm critiquing your guy and his trouble shooting.
#3430 of 3508 Re: 2000 Buick Regal LS [imidazol97]
Apr 15, 2009 (9:17 pm)
Wow! That's about the most comprehensive treatment of the Regal problem I've received thus far. Many thanks; I will use the message as a checklist.
Regarding the battery cables, etc. I noted this problem happening a while back when I turned the radio on. But, the car has run very well with the radio on and off since then. I have switched everything electrical on and off while driving, and none had any bad effect. When the car stalls, the radio continues to play.
My son called on his way home this evening and said the Buick was acting up again, stalling when coming to a stop. He used the technique of shifting into neutral, restarting and feeding the gas to keep the revs up while still rolling. Since this happened at night, the normal dashboard panel lights are lighted, but no warning lights are showing, a condition some have noted in other forums. I think that rules out an ignition problem?
The odometer has been dark for several months, and the gas gauge is unreliable, but he did refuel earlier this evening, so it was not an out-of-fuel condition.
Thanks again! I'll try what is within my expertise, and check back with you.
#3431 of 3508 Re: 2000 Buick Regal LS [bsamstag]
Apr 16, 2009 (5:05 am)
Check both ends of cables to battery for corrosion. If you have the double positive cable with a large plastic cover over the ends, cut into it. A few people found a lead spacer (on H_bodies) and corrosion. One or more found the copper cable corroded and gone due to acid or something else.
On H-bodies (leSabre Bonneville Park Ave) there are ground busses in cable bundles that are under the carpet at the front of the door sill, on both sides. Those have corroded due to moisture and salts for some people. I don't know if your car has those.
Have you tried disconnecting EGR yourself and driving? The MAF sensor also can cause stalls but usually people have other running strangeness happen with MAF.
I still recommend taping a fuel pressure gauge to the windshield to see if your fuel is dropping pressure. Some cars are sensitive to a tired fuel pump not quite making exactly the pressure range required by the injectors to give a proper spray pattern.
A professional mechanic, trained at Cincinnati area vocational school and owning a body shop auto mechanical repair garage in upscale Cincy, talked on his radio program about taping gauges on and driving customer cars to try to catch a pump problem.
You need to eliminate things one-by-one.