My LeSabre won't start when it is outdoor and cold. It will start in a cold garage just not outside. I have replaced the fuel pump, fuel filter, all the plugs and the plug wires. It runs good except when it is cold. I have to pump the gas and eventually it fires up. Once going it will start easily the rest of the day. As long as it is in the garage it is fine. I did test for spark at the plugs and the module and there is spark. I also checked the fuel injectors and they are working too. This is a mystery to me. I hear lots of talk about the sensors but is there anyway to know without changing them one by one?

Not reallly...

There are many things that have to happen..
When you first turn start your car usually pre injects fuel at the start for a cold start. Apparently thats not happening unless if fires and quits. If it doesnt fire a bit and quit that would be a Computer problem.

One sensor (MAF) checks for air flow.
Another (IAT) intake air temp checks for air temp.
Another (ECT) checks for a cold engine.

The computer deduces from these sensors what to do.

The car seems to think its warm when it isnt, so I would suspect a temp sensor unless theres a fuel flow problem.


Good Luck



Edited by: bassasasin

I had an experienced car tech run a diagnostic on the car after a really cold night. The first thing he noticed is the car has NO crank signal so the senor is bad. He also said the ECM said the car was running lean when in fact it was running rich. He mentioned some other techno stuff I don't understand. I'm going to replace the crankshaft sensor and the ECM and see if that doesn't fix it. I'll look up the sensors you mentioned in your reply too. Thanks!

With no CPS Crank position sensor signal.. there is abslolutely no spark, no firing, no ignition. Thats not to say yours gets some signals and they fade away as the engine warms.. but when they do dissappear completely, during a run the engine abruptly, absolutely quits.

I dont suspect the ECM yet.. Perhaps the ECT..

The wild thing about this 1990 LeSabre is when it does start it runs great, gets good gas mileage etc. It is amazing that when the wind is blowing the the temps are below freezing it refuses to come out and play. This car was given to me and was mostly driven in Arizona and now it must endure North eastern Ohio. Perhpas the car wants to go back to the desert. The tech who looked at the car was convinced the computer was bad. He also told me the scanner was reporting NO error codes. Instead the ECM was confused and didn't know exactly what to do. Mind you I'm a pastor not a mechanic so he was talking down to my level. Today we're going to replace the ECM and the CPS and see what happens.

The ECM is an easy thing if you can get a cheap one..Junk yard.
THe CRankshaft sensor usually throws a code to the computer. But often it throws a Camshaft code.


However, You did say you had spark at first post.

Checkin for Fuel starvation. If you spray starting fluid (ether) (Ive done WD40) in the engine when the engine very cold does it start.. fire whatever. This tells you you have a fuel problem and not a ignition or Crankshaft sensor problem and you can take a different course.
Fuel pulses do come from the ECM.


Divide an conquer.


In the samelogic can you check for spark when the engine is very cold.


Ignition modules under the coil pack get cold too. Short out spark, quit etc. If you do the junk yard run.. get one of those too off a wrecked car.. a smashed car was running..



Good Luck


Edited by: bassasasin

This car will not start or even sputter when cold. In fact it backfires and smells like gas. I didn't get to replacing the ECM yet but I plan too. I got a new one for $80. I'm thinking the module might be bad and if this doesn't fix my problems I'll be off to the junk yard. Since the car was a freebie why night put some work and money into it. It only has 80K for mileage and I hope to baby it for at least 100k more!

What you just said. tells me you may have ignition problems.. Meaning the crankshaft sensor or ignition module is still a focus..ECM wont hurt still.


Rev Bass


Edited by: bassasasin

ECM is replaced along with the crankshaft sensor and still the car will not start when cold. I sprayed starter fluid into the intake and this had no effect. I guess the next step is to look for the ignition module. At what point do you take the car to a Buick dealer? I guess if someone can diagnose the problem I can get the parts and do it myself otherwise I am going to have to let it sit until warmer weather comes.

Edited by: davchrwoo

Were you able to divide and conquer? If there was spark the spray would have fired a bit..


Im going to assume you proved ignition problems.. somewhat.


The ignition module is under the coil pack. Its flat and the coil pack usually screws onto it. You could get some very hot water in a jug and after the car was cold outside pour that hot water there and warm it up alot. Maybe even 2 gallons.


Theres lots of possibilities..If its not a module its wiring.. and wire checks are necessary. But Im still on a module.


I have recently read some interesting info yesterday... Leaking injectors will cause a hard to start when cold condition... they leak when cold.. which would give you a rich condition.. thats what I learned..But you said no spark when cold.. But we are chasing spark right now. .


Personally I would never go to a dealer. They are good trouble trackers butget paid for it. I like the challenge. hang in there.





I am..