95 LeSabre

:crying:
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. :banghead:

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?

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.

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.

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.

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?

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?

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?

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.

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.

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.

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:biggrin:

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

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

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?

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?


The first thing would be spark plugs and wires might be giving a misfire under the highest load conditions which is slight throttle opening. When you open the throttle more, mixture becomes easier to fire.

Also could be coils.

If you think tune-up stuff is okay, plugs, wires, etc, the first thing I would do is remove the vacuum hose off of the egr valve and plug the hose with a bolt or something and road test. There used to be alot of driveability
problems related to egr. You might get some pinging so don't beat on it.
Just drive enough to determine if that is the problem first. If it does turn out to be that, then the egr solenoid needs to be checked also.

I have not given the car a tune up and I don't know when it was done last but the plug wires are not original so they were replaced sometime in it's life. I will pull a plug and check today. And I will plug the EGR line also and check for drivability also, never thought of that one. Also I have no check engine light one either? Remember it runs fine and starts fine just that little annoying stumble at light throttle position. Thanks

With it running good I would still start with egr. Couple things, the pintle
inside the egr can get carboned up causing it to stick ever so slightly and cleaning can cure that. The spring inside of it gets old and week, not servicable, causing it to open suddenly rather than a smooth slow opening or cause it to flutter. The egr solenoid not controlling the egr correcltly. Usually if the solenoid craps out you would get a code and you say you have none. Spring issues inside egr's were most of the problems with'em.

Well I changed the EGR to one I had that I know is a good one from my 84 parts car.
I felt no difference in the drivability. The more I pay attention to the way this feels the more I think it's a miss. I did replace the ICM and the 3 coils as part of my original problem so I know the "coil pack" is working fine. I didn't get a chance to pull a spark plug but like I said the wires are quite new so I assume the plugs are also, I know I know, don't assume. There is a good story that goes with the parts car that I would pass along if your interested, it will explain why I know the parts off it are good.

Okay, first, all you needed to do was plug off the egr vac line, no parts changing. Still, do that, then go on.
What's the 84?

Do a compression test. This and a vacuum test will give you gobs of info about the health of your engine. Once you know the engine is either good or bad, you can proceed. If your tests come out all good, then you can look to an electrical/fuel/ignition cause. If bad, then you know you need some mechanical work and you won't need to waste time chasing the problem further until/unless you fix the mechanical problem.

On both my 92 Lesabre's they did the same thing. It turned out to be pitting/wear on the cam shaft that caused slight missing. The only fix in my case turned out to be rebuilding both engines (and replacing both cam shafts.)

I would agree with spinne1 which should also include a cylinder leak down test, but, it's only an off-idle situation. I would have thought that if the cam lobes where worn down enough to give a skip condition that it would have been occuring throughout the entire rpm range.

I would agree with spinne1 which should also include a cylinder leak down test, but, it's only an off-idle situation. I would have thought that if the cam lobes where worn down enough to give a skip condition that it would have been occuring throughout the entire rpm range.

You are correct, mine was throughout the rpm range and therefore it was not exactly the same condition as the original poster's problem. Yet, it did act more problematic the more you put down the accelerator. Nevertheless, he should have the health of the engine checked out.

I just tried the plugged vacuum line to the EGR valve and no change. And as you know there is really no problem changing the EGR valve, on top of the engine etc. The only problem that most people would have would be the replacement cost and that's not an issue to me as I have a complete working parts car, for now anyway, the wife is getting tired of looking at it in the drive way! I will do the vacuum test today, I don't think I have time to do a compression test but I will do that soon. Thanks for the info, I really should have thought of that myself but I tell you under most conditions it runs perfectly! Most normal people would not even chase the intermittent hiccup.

..What's the 84?

Let me answer that!
:biggrin:
The 94 is my 1994 LeSabre Custom parts car with 155,000 miles on it. We bought it new and thought it was in good shape until one day my wife was driving it to work and the engine fell out of it! Well not exactly. She pulled off the side of the road to make a phone call and when she was done she put it in gear and pulled away. The car made a load BANG sound and she had no steering. So she coasted to a stop and backed up back onto the shoulder. When she called me to complain about the old car I thought it would be just the universal joint in the steering linkage had broken and would be an easy fix. When I got there there was a six inch space between the rack and the steering linkage. Looking under the car The four rear bolts that hold the front engine, transmission, front suspension sub frame in had rusted off and the engine sub-frame was just held in by the two front bolts. Go figure, I never heard of that before! Anyway that car was running and driving perfectly before it totaled itself so it's a great parts car to fix up the 95 with.

PS: I never got the vacuum test done today, perhaps tomorrow.

I have not given the car a tune up and I don't know when it was done last but the plug wires are not original so they were replaced sometime in it's life. I will pull a plug and check today. And I will plug the EGR line also and check for drivability also, never thought of that one. Also I have no check engine light one either? Remember it runs fine and starts fine just that little annoying stumble at light throttle position. Thanks

Check resistance of each ignition wire, they should be less than 1500 ohms per ft. If you find any more than that, throw them in the garbage and get some high quality wires like Belden, ACDelco, or MSD. Replace the plugs if you haven't already done so, and set the gap @ .055 instead of .060. You could have a weak coil and if the above recommendation does not solve your problem, check the coil(s) resistance. Primary side should be .5 - .9 ohms and Secondary should be 5K to 9K.

Some Basic Electrical Knowledge:
· Voltage is the force that causes the current to flow.
· Current (amperage) is the amount of electricity that is flowing.
· Resistance is the restriction that slows down or stops the flow of current.
· The greater the resistance the less the amount of electrical flow.
· A ground is a connection between an electrical circuit and the earth.
· Electricity always seeks a ground.