88 LeSabre won't start when cold

[buickmastermind]

Yes, the CRANK sensor is used, but not the CAM sensor. Two totally different sensors that are used to measure two totally different values don't perform the same operation. I would rule it out the CAM sensor because:
The cam sensor is only read by the computer above 400 rpm and below 1200, when the ICM is in Closed Loop Operation. That means that the motor has to be warmed up first before it uses the inputs from the cam sensor, the O2 sensor, and others that don't apply to mine that do to the newer ones.
A motor is usually going to idle at 1200 rpm for a few seconds when you start it cold. As the motor warms up, the idle slows down, until it reaches about 800 rpm. At that point, it begins to use the different sensors not used at startup. When the car has been driven for about 10 miles, the motor heats up more. Under this condition I have seen a 455ci v8 idle at just over 500 rpm, but never less.

[keepingitontheroad]

Originally Posted by buickmastermind

Same thing I stated above about the coils. You also might want to make sure the battery has the correct voltage when cold. When it runs, is it smooth, or does the motor vibrate?

Sorry about the double post!!

Although I haven't actually measured I beleive the battery voltage is good when cold, I will test. When the vehicle runs it runs smooth. The only times it ran rough I was able to replace plugs or wires to correct. One note, it doesn't seem to take long after replacing the plugs that I need to replace again (6 months). The old plugs look fine but there will be a noticable improvment in how the car runs. I also seem to have replaced faulty ignition wires before they should have needed to. Having said that, replacing plugs and wires have never made the car start any better when cold. I've had this sypmtom for 5-6 years at least, just seems to have to be less and less cold for the car not to start.
When you talk about the ignition coil you are refering to just the coils and/or the ignition module?

Thanks

[avatar307]

The coils are the little units mounted on top of the Ignition Control Module base. If your plugs are needing to be replaced that often to get the engine to run right, I'd expect at least one of the coil packs isn't putting out the needed voltage.

Since the engine is only having problems running when cold, and most of the sensors on the the engine are not monitored until the engine warms up, I would suggest checking the EGR valve. It should be open when the engine is cold to introduce hot exaust into the intake. This increases the efficency of the fuel/air mix.

If it is not opening, or the passage ways are blocked by carbon build up, this could definately be your problem. As it is a 1988, the EGR should be controlled by vacuum pressure alone, and the solinoid is likely not monitored. Thus, the engine assumes that below a certain engine temp the EGR will be open. If it is not, the engine would be sending the wrong varibles to fuel injectors and such.

As the EGR is most likely controlled by vacuum pressure genrated by the intake manifold, you should check all your vacuum lines for leaks and such. Depending on how the manifold is laid out, one vacuum leak can affect multiple systems simultaniously.

[buickmastermind]

To my knowledge, the EGR valve is suppossed to be open only when the tranny is in gear, but that may be different for the 3800 than mine. I would also make sure that the O2 sensor is working correctly, but the main thing would be the coil(s).

[keepingitontheroad]

Just wanted to thank Buickmatermind!!

I replaced the Ignition coil and the module (bought one from auto wreckers) and the difference in how the car ran was immediately noticable. I was able to start the car this morning (temp was couple degrees below zero overnight) no problem. Even at this temp in the past I had real problems starting if I could get it to start at all. It will be interesting to see how the car starts when it gets real cold (-30) as we get in the winter, here's hoping.
I will post a follow up later this winter.

Thanks again

[avatar307]

*shudder* Everytime it drops below 0 F here, I have to buy a new battery. Oh well, doesn't cost me much more than the frustration. It's Texas after all... it doesn't drop below 0 but once every 5 years. LOL

[Jed Rule]

I used to use starting fluid on my 88 when it was cold and then I found there is an up-dated PROM for 1988 that enriches the fuel mixture when cold. Check with your local dealer. Easy fix. Not too $$$

[O.P]

I still havent fixed mine, has anyone fixed their problem?

[keepingitontheroad]

Originally Posted by O.P

I still havent fixed mine, has anyone fixed their problem?

I too had the same symptoms you described in your previous posting.

I took the advice of "Buickmaster" and replaced the ignition coil and ignition module (I have '90 lesabre 3.8). I got the coil and module from a wreckers for $90. At the same time I replaced plugs and ignition wires. My car is now starting great. Last night it was down to -7c (20F) started no problem. It would never have started before. Time will tell wether it will start as good when it gets real cold (I'm in Ottawa so we get -30 and lower in the winter).

Bottom line - so far the car is starting (and running) better than it has in 5-6 years.

[O.P]

Keepingitontheroad, did you get any trouble codes before you fixed the problem?

[keepingitontheroad]

I checked trouble codes several times and never had any!!

[buickmastermind]

O.P, are you getting any? That might help resolve your problem if you did.

[psycotic]

I'm having the same problem with my 88 lesabre. I've had the car for 5 years, and it was a graduation present from my grandparents. This car came from florida. Everytime it gets below 25 it starts really hard, under 10 it almost refuses to start. I've thought about a heater, but decided against it as i have no place to plug it in at work.

One of the guys at autozone told me that maybe the computer module was to blame as it came from florida and they may not include the programming for cold weather for the choke.

i changed the icm in july thinking that was the problem but now its december and it didn't help. i get good spark, fuel, and all the other junk. once started the car runs fine, but if sat for 8+ hours it doesn't want to start.

I'm wondering if i am not getting enough gas to the plugs. thats the only thing i can think of.
i'll check the coil pack.

[sallisonbrown]

Sounds like you need new wires (and maybe new coil packs). I don't think GM has any compensation in the computer mods for area weather. Generally we just compensate by using different grade oils.

[psycotic]

its actually got new wires and plugs. i get good spark on the coil pack. so idk.
is there a possibility that the computer uses the temperature sensor to determine the amount of fuel needed to start the car, if so maybe thats bad.