95 LeSabre

[BoB393]

Well here we go again.
I've got an intermittent no start with my LeSabre.
When it runs it runs fine, starts fine, etc. Than out of the blue it won't start!
Like right now.
It's raining but it happens when It's dry. It seems, at least the last several times, that its a bad connection under the dash. If I pull and push on wire it will start, of course not this time.
I have tried to start it on starting fluid but no go, pulled a wire and no spark. I swapped out the ECM with a good one and no start.
Anyone have any ideas where to start. I swapped out the coil pack last time and it started. No check engine light on. I'm at my wits end. Help, Please.

[HotZ28]

Have you ever had the crank position sensor changed? Pulling on wires to get it to start before sounds like you may be loosing a ground somewhere. Check the ground under the ICM/coils and the one on the right front fender, they must be clean & tight. Do you here the fuel pump prime for 2-sec when you turn the ignition switch on? Any wet carpet in the car?

[BoB393]

Yes the fuel pump does prime. Actually the wires I pull on are the wires under the dash.
I have never touched the wires under the hood. It is the original crank position sensor.
This all kind of started when I was removing an after market CD player. I figured I had pulled a wire loose when I removed the player. That doesn't seem to be the case.
On dampness, absolutely yes. I got a killer price on the car because the car was sitting and was soaking wet inside. I have replaced the seats and carpet from another car I had because they smell so bad. So yes, if you have any moisture related ideas bring them on.

[BoB393]

Well I changed the Ignition module and coil packs with a known working set and I thought I had it fixed. Nope today it wouldn't start. I tried tapping the Crank Position Sensor but nooo it still will not start. Turns over fine just will not fire.

Do we all agree next on the list is the CPS. And how big a job is it to get under the harmonic balancer? It's only a $35.00 part but looks like a nightmare to change.

[key1911]

Are the wires under the dash you pull on near the fuse panel? From memory, I recall a ECM fuse in there. I have encountered fuse panels with corrosion from moisture and of course get bad or intermittant connections.

[BoB393]

Most of the wires were on the opposite side by the passenger foot well but I was working on the fuse side also. I'll try pulling the panel and having a look at the back of the fuse block for corrosion. Thanks

In my original post I said when it runs it runs fine. That may not be true! Today I noticed a bit of a miss when I gently applied the throttle.
Flooring it seems to smooth it out. Just a new observation.

I just tried the light bulb in the injector socket trick and I got no flashing light when I cranked the car over. So if this is a valid test I think I will be replacing the CPS soon.
I'm just suprised that when I tap on the connector it doesn't work? Any thoughts?

[BoB393]

Just one more update. When I changed the ICM and coil pack I cleaned all corrosion from under the mounting plate and re-tightened the ground lug from the battery. I just cleaned the ground on the right fender and still no start. Just a side note, it could be moisture related as it is damp, just rained, today. But it didn't start for me on a dry day also. Who knows?

[key1911]

CPS's were problems back then, but ya just gotta make sure all else is okay before replacing one. Was the ECM inside the car?, and while I think of it, why was the whole car wet, and, are you near salt water, and, I know.... how many miles on the car?

[BoB393]

The ECM is inside the car by the passengers footwell. The car was sitting for about six months with the passengers window cracked open. The carpets and padding was 100% soaked. You can not believe the smell! The car has 175,000 miles on it. I bought a new CPS last night and I'm changing that today after all the Mothers Day things. I'll let you know if it works.

[key1911]

Just make sure to line up the sensor with the ring that is on the back of the crank pulley. We use to pull the wheel and do it through the wheelwell. Once the crank bolt is loosened, the pulley should almost slide off on its own. It is not like chevys that need a puller to get them off. Also we had a tool at the dealership that looked like plastic feeler gauges, install the cps and carefully slide the pulley back one, then you stick these gauges in, it centers the cps, then you can tighten the cps and reassemble all components.

[BoB393]

It's all changed! Not as bad a job as I expected except the harmonic balancer bolt was a bear, had to use an impact wrench, and it did not slide off the crank nose after the bolt was removed, had to use a puller. But the job is done. Thank god you mentioned to go in through the wheel well as I was planing on doing it from the top and removing the motor mount. That made it about 100 times easier. Thank you. Oh yah I think it worked. It's started about twenty times now since I finished and I detect no stumbling at low throttle positions. The car still has spit out no fault codes though.

[key1911]

Cool, good to hear "so far so good". The snout on the cranks of those aren't tapered and usually take very little persuasion to get off. Maybe some road salt gave it corrosion. We didn't see many buicks at the dealership with that high a mileage either, less time to fuse themselves

[HotZ28]

Actually, to remove the balancer on the VIN-L & VIN-1 after 1991, they all require a puller.

[key1911]

Good to know, I left Buick 90-91, somewhere around there.

[BoB393]

Yup! 350mi and 25 or 30 starts with no starting problems.
It would appear that that was the problem.

Now a new problem we can hash out. At cursing speed, sort of because it appears to be throttle position sensitive, there is what feels like a slight misfire, a bucking like the engine is missing a beat. Now to really make things hard it's intermittent! If I curse at say 70 on a flat road with just enough throttle to hold the speed it will do it. A soon as I push down to accelerate it goes away. 70 is not a magic number mind you could be 40. Gentle acceleration up hill will do it but it goes away under hard throttle. When it first happened I thought it was the lock up solenoid in the transmission, a problem I had in the 94, but I could make that go away in my 94 by shifting out of over drive and driving in 3rd. This car the 95 it will continue to do the same thing just at a higher RPM.
Just a note that under full throttle peddle to the mettle passing RPM's it runs smooth as silk with plenty of power, more than the 94 I might add. It's at that partial gentle cruse throttle position when you move the peddle a 1/4 of an inch up and down to maintain speed that it does it, just when it's most annoying.

Any thoughts?