90 Regal GS will not start

My GS started doing something weird the other day and now it is getting worse. Sometimes it will start right up, and sometimes it will only turn over. When it will not start, the service engine soon and low coolant lights are flashing. As long as these lights are flashing it will not start period. If you leave the key on, it may take 10 minutes or more, the lights stop flashing and it will start right up and run fine. I have checked and cleaned all the grounds, but still the same thing. Any ideas? Thanks in advance, Richard:banghead:

Anyone?

I'm not familar with the older Regals, what motor do you have?

It is a 3.1 with 163000 miles on it. Up until this problem started, it has been a very dependable car.

Are any relays &/or solenoids in the engine compartment clicking while the SES & coolant lights are flashing?

The only thing I can hear or feel clicking under the hood is the idle speed controller. When it stops clicking, the lights have stopped flashing. I have disconnected isc when the lights are flashing, but no change. as long as those two lights are flashing, it will not start.:banghead:

You might have a bad computer. Did you check for any codes?

I put the scanner on it and no codes. When I had the scanner plugged in, and turned the key on, The lights were flashing, and the screen on the scanner said that communication with the vehicle had been lost. Without disconnecting the scanner, I waited a while and turned the key on, the lights stayed on steady, the scanner was communicating, but no codes.:banghead:

Check your connections at the battery. Most of the GM cars have two positive cables that come together under a rubber boot. Pull the bolts from the cables & remove the rubber boots. Clean the bolts & both sides of the cable ends & spacer. Apply dielectric and reassemble.

If cleaning the cables doesn't help then I'd pick up another computer (ECM) from a junkyard. Swap the PROM chip from your ECM into the replacement.

That Regal has a split positive cable. One branch goes to the starter, the other to the underhood fuse/relay center. Check the cable and the underside of the relay center for corrosion. If that all checks out, you either have a bad ECM (very common issue on these cars due to being mounted under the hood) or a bad ignition switch.

Thanks, I will check all this out. By the way, does any on have a factory service manual in pdf format?:banghead:

I checked all battery cables and they are clean and tight. I unbolted the relay center and it also is clean and everything is tight. I will see if I can find a used ecu and try it.:banghead:

Well, it looks as if I have a bad battery. After the car sits all night, it will start, then if I shut it off right away and try to restart it, the lights will start flashing and it will not start. When I put the battery charger on it, It shows that the battery is almost totally discharged. I took it to Auto Zone and had it tested, the charging system checked out fine but the battery didn't. So for now, untill I can afford to buy a battery, I will just keep the charger on it. Thanks for all the help. I still need a service manual in pdf format if anyone has it. Thanks, again.

Well, I put a new battery in it and thought it was fixed but I was wrong. I drove to my brothers and coming home after driving about 80 miles, and the engine started cutting out and the service engine and low coolant lights started flashing and it died. I was running 65 mph at the time. I coasted to the side of the road and waited about 10 minutes, turned the key on, and the lights weren't flashing so I started it up and drove the remaining 25 miles home without any problems. I'm about to pull my hair out on this one. I don't know where to go to from here.

Ideas? Anyone?:banghead:

I'd still try another ECM. Most junkyards around here will let you return a part that doesn't help, so it won't cost you anything if it doesn't fix the problem.

Are you sure the alternator is keeping the battery charged?
You should also make sure the battery cable ends are corrosion free. A lot of the GM cars have 2 positive battery cables that come together inside a rubber boot. You need to remove that rubber boot to clean the corrosion off both sides of the cable ends & the spacer.

The alternator charges fine. I did check all the cables and they are clean and tight. When the lights are flashing, it turns over fine, it just wont start. And like I said earlier, I was driving down the road at 65 mph, when the service engine and low coolant lights started flashing and it died. I waited about ten minutes and it started right up.:banghead:

I assume coolant level is where it should be and engine does not overheat.

Is it possible that you have a faulty coolant level sensor that when light flashes it shuts off the fuel supply so engine dies as in a safety feature.

As stated in other posts it could be the MEM-Cal/Prom/KS in the ECM.

Go to this link, it is not a FSM but it may help:

http://www.bedlib.org/ebsco.html

click on ARRC
enter library for userid and password
click on auto repair reference center
choose year, make, model and engine

Do you have fuel when engine dies? Have you tried squirting carb cleaner into air cleaner to see if it will run when this happens?


Hope this helps

No engine overheat. I have unplugged the coolant sensor with the engine running and it did not shut it off. When the service engine and low coolant lights flashing, I have fuel or at least you can hear the pump come on, but no spark.

Well, I put a new battery and new ecm in the car and for the last couple of weeks, it has been starting and running fine. Yesterday, it started doing the same thing, Low coolant and service engine lights flashing, no start.I left the key on with the lights flashing to see how long it would take for them to stop flashing. After about 2 minutes, it sounded like a relay started chattering hard and loud, the lights stopped flashing, and it started right up. When I heard the loud chattering, it sounded like it was comming from the right front side of the car. I looked, and couldn't find any relays. Any ideas?

Does your car have the resistor pellet in the key (I can't remember when GM started doing that)? It sounds like a security module issue.

No security.

Are you sure the alternator is charging the battery?

Yes, it charges great. The engine spins over great, but will not start as long as the lights are flashing.

Buying a junkyard ECM for one of these cars is a dicey issue. This is a VERY high failure part (especially in states that use salt on the roads in winter). The chance of you getting a good salvage yard ECM is scarce at best. Also, did you transfer the E-Prom from your original ECM to the new ones, or did you just install them as pulled?

Brand new ecm, not a used one. Installed original e-prom.

Well, it has been almost 2 months without any problems. Today, it will not start. The low coolant and service engine lights are flashing and it will not start. It turns over great, has fuel, but no spark. Normally when the lights are flashing, you wait about 10 to 20 minutes and it will start right up, not today. After about 4 hours, I went out and tried to start it. It fired right up and ran about 2 minutes. The cooling fan started to come on and it died. The low coolant and service engine lights started flashing and that is it No start, and has been that way all day. I'm about ready to run it across the scales and sell it for scrap. Any other ideas?

OK. The problem is corrected. The e-prom was bad. That was the only thing that was not replaced, so I went to the junk yard and found a car set up exactly like mine, pulled the e-prom, installed it, the car fired right up. I have driven about 200 miles, highway and in town, even shut it off and restarted it several times, and everything is good. A couple of days ago, if it started,and you drove 1 mile, if it did not quit on it's own, and you shut it off, it would not restart. So far it is a good feeling not having to worry about it not starting, or quitting. Thanks all for all the help.