Im Ready To Set My Old Buick On Fire ..Help !

This car has me pulling out my hair ! The problem is not constant..Hard to test problems that way .
The problem is the motor runs fine for about 20 miles then starts acting up .
In this no run condition there is no spark and no fuel in the run position of the switch .
Pump runs for 3 seconds w/ key in run and has 35 P.S.I. fuel pressure
What I have done so far :
New fuel filter
new pump relay...pump was replaced 6 mo. ago.
New ignition control module
New crankshaft sensor
New ECM .

Original problem comes back .! Wait 10 minutes and it restarts .
The only thing left to try is the ignition switch itself..Poor or burned contacts in it may be .
The car is a 1989 Buick Regal w/ 3.1 L V6 ..My only transportation .
The thing is ..im a heavy equipment mechanic Not a car computer analist .

Any car tecks to help an old man out..@ 62 I dont much like walking !

Use some old newspapers in the back seat a little gas and a match.

That should fix it.

Sounds like you either have a bad coil, or you need to replace your fuel pump again. It happens. Do you remember what brand fuel pump went in?

Look for vacuum leaks. I had a similar problem on a car once, turned out to be a vacuum hose that opened up as the car got warmer. It was a fuel injected v8 but it taught me a lesson.

Originally posted by granpabobby
This car has me pulling out my hair ! The problem is not constant..Hard to test problems that way .
The problem is the motor runs fine for about 20 miles then starts acting up .
In this no run condition there is no spark and no fuel in the run position of the switch .
Pump runs for 3 seconds w/ key in run and has 35 P.S.I. fuel pressure
What I have done so far :
New fuel filter
new pump relay...pump was replaced 6 mo. ago.
New ignition control module
New crankshaft sensor
New ECM .

Original problem comes back .! Wait 10 minutes and it restarts .
The only thing left to try is the ignition switch itself..Poor or burned contacts in it may be .
The car is a 1989 Buick Regal w/ 3.1 L V6 ..My only transportation .
The thing is ..im a heavy equipment mechanic Not a car computer analist .

Any car tecks to help an old man out..@ 62 I dont much like walking !

Your problem here is the Main Relay if this model has one and i bet it does.

Its not the fuel pump relay.


My 1990 Honda accord had the same problem and that was the cause.

It would go dead with no power at all.


And if it dosent have one look for the map sensor.

www.am-autoparts.com...

Originally posted by MoosKept240
Sounds like you either have a bad coil, or you need to replace your fuel pump again. It happens. Do you remember what brand fuel pump went in?

Yep, I was a parts manager for some years, and in the older vehicles if you did not clean out the tank properly before installing the new pump, the sludge in the bottom of the tank would just kill the new one in short order. If you do end up pulling out the pump, and the pickup sock is very dirty that is your problem.

well thats what you get for driving a buick

reply to post by granpabobby


have you tried disconnecting both battery cable leads for five minutes then re-installing the cables onto the battery? sometimes one of the many sensors, modules and electronic brains can get problematic, and this would re-set them.

also: your local library has automobile manuals you may use. you may have to request the one for your vehicle, and in a few days they will have it in from the main branch. usually one is not permitted to take out reference books. look up your situation, find the diagnosis, then make copies of those pages using their copy machine, which will require pocket change.

best of luck.

PS: also sounds a little like vapor lock.

When I installed the new ECM i had to remove the PROM from my old computer and install it in the new ECM
Did I Perhaps transfer the problem ? Who has a PROM for this computer ?
useing a jumper wire in the no run condition the fuel pump puts out 40 psi.
I use an inductive timeing light to check all three coils..no spark.then as suddenly has spark and runs .
Car has OBD ! type computer .All relays replaced now ..Fuses ..need to check them next time it leaves me on the side of the road (see if they have power )
20 inches vacume no fluxuation when running
No codes shown ..Tests with scanner show no problem

"The only thing left to try is the ignition switch itself..Poor or burned contacts in it may be "


yes this is a common problem. Pop off the switch use a knife or something sharp or a file and sand down the contacts reconnect and you should be good to go

reply to post by LargeFries

Will need to do this as I need the electrical schematics and computer pin voltages to ck for a loose wire.
Fuses not haveing power to the ignition modual or the ECM in a no run situation would indicate the ignition switch.
This switch is repeatedly turned on and off trying to get it started...sometimes it has a "funny " feel to it like it hangs for s split second.
Will replace it Monday and see what happens

New problem has shone up today I drrove about 10 miles and turned the car off..no restart..after about 5 try ..of turneing the key on and off it started !

I hate computer cars...where are the points..distributer and carbs ?. Old School !!!!

that era gm cars vans had a problem with the main harness junction at the firewall. there is a center screw that holds the two plug ends together(it should be about a 2inch by two inch mess of wires) with car running look under dash find main junction connector and wiggle wires if it dies problem found.if so loosen plug clean pins check for tightness,reassemble

Originally posted by automata
that era gm cars vans had a problem with the main harness junction at the firewall. there is a center screw that holds the two plug ends together(it should be about a 2inch by two inch mess of wires) with car running look under dash find main junction connector and wiggle wires if it dies problem found.if so loosen plug clean pins check for tightness,reassemble

This I will try in the mourning ..Hope to make it to the job .will try this when I get home ,

Thanks for the help !

I have some 40 years experence as a heavy equipment Diesel and gas engine mechanic As well as being a heavy crane operator..

My own car is makeing me look a fool..and im not !
Intermittent problems can eat your lunch ..

It would be easy to find if it would just quit..then one can find the problem .!

reply to post by granpabobby


Here is the tech. Access and unplug the ECM, and wait 30 minutes. Plug it back in, drive the car for a few miles. GM cars have a logical Electronic Control Module, it learns as you drive. It has learned you had worn out parts, and compensated. When you "reboot" it like I told you, it will relearn and record default settings.

If this fails, I know what else could be wrong too, U2 me, and I will tell you how to fix it.

Did a wire wiggle test on ECM firewall connection .and ignition switch module with engine running NO change..
Disconeted ECM and battery..10 minutes reconnected..NO change.
Have a new ignition switch module which includes the high beam switch..this is going to be fun to change..have to drop the collum

OK, I know another thing that could be the root of the problem. Bear with me here. If you look at a GM wiring diagram in Mitchel's, trace the orange wires, you will see that all power supply wires are in fact orange, or orange/black stripe, and all come together at a common point. This point is under the dash and carpet, and takes more than a few hours to fix. First, find the wire bundle and trace it until you find the point where they all come together. Un-ape the wires as you go. You will see, when accessed, that at least 11 power supply wires come together, with no fuse of breaker of any kind. Usually there are 5 on one side, 6 on the other, more accessories means more wires. This is General Motors built in obsolesces. Say that that little switch on the door that turns on the interior light get wet and shorts. This one short is far reaching. Voltage drops.Things began to go wrong, Engine refuses to start, then starts later. Light are dimmed, or flashing.

What we do is buy one 50 Amp automotive circuit breaker from an auto parts store. Cut the wires, and, and place a ring type terminal on each wire, keeping then separate, some on one side, some on the other side. Place the rings on the breaker, tighten the nuts, and tape it up real good. Put the dash back in, and screw everything down tight.

You will notice a vast improvement right away. More power is available, lights are much brighter, every electrical device works better.

For a good wrench this is a 2 & 1/2 hour job. And it is worth the effort. We charge $250 to do this, and every time it is very successful. Try it if you dare, and good luck to you. Once learned, you can make money off off your friends fixing their GM cars and trucks. Every GM since 1986 had this built in problem. Fords and Dodges are different, I am GM trained.

I have an update !

Changed the ignition switch module ..The car is still running ...Tomorrow it gets a 40 mile round trip and we will see how it goes..

Disected the old switch..found a burned contact..Hope that was it..we shall see !!

reply to post by autowrench

Need to replace the heater core will do the wireing mod at that time .Thanks for your help !

Originally posted by granpabobby
I have an update !

Changed the ignition switch module ..The car is still running ...Tomorrow it gets a 40 mile round trip and we will see how it goes..

Disected the old switch..found a burned contact..Hope that was it..we shall see !!

son of a gun! and you suspected this all along!

i thought perhaps the one poster who mentioned replacing a wire connection block was on to something, as well. aging cars can develop wire / terminal probelms.

glad you found the culprit grandpabobby! while i'm sorry you had this PITA, this was probably the most fun thread i've seen on ATS. reminded me of the good old days, reading the small-format Popular Mechanix, or was it Mechanics Illustrated, that had a good column where a customer would bring in a strange problem and Mr. Fix-It (or whatever his name was) would inevitably figure out the mystery and share it with us in story form. Man I miss the days when regular guys could work on cars with a small box of tools!