1995 Cutlass Supreme headache

[sdwhite]

Hello all-

 

I've inherited a '95 Olds Cutlass Supreme and it's making me .

 

It has 200K on the ticker...lots of highway miles...still has original GM muffler.

 

I inherited it because it runs for crap. It barely idles, sometimes dies. Has absolutely no power when driven.

 

Has new Bosch 2 platinum plugs, new plug wires & PCV valve. I cleaned out the EGR passages, the IAC valve and the Throttle body with TB cleaner. Has 5 gallons of fresh gas that made no difference.

 

I put a timing light on each wire to see if it was firing. My timing light might be shot...I got it to flash on each wire but only for about a second or two. I tested it on a known-good engine and it was similar. Is there a different way to test for spark?

 

How difficult is it to change the "Lower" intake gasket? Apparently the previous owner changed the head gaskets and intake gaskets looking for this problem. Do you have to change the lower intake gasket to change the head gasket? If not, that may be the issue.

 

How similar is this '95 3.1 to my '93 3.1, mechanically? I mean, Could I use my 93 3.1 GM Engine Service Manual to service the '95?

 

Any other hints or suggestions?

 

Thanks

 

Scotty

[gp90se]

first of all, get the bosch plugs out and replace with delcos and see how it runs. bosch foul out very quickly in these cars because of the waste ignition system. does it sound like it has a miss? does it idle high? engine light on?

 

when doing the head gaskets, its a good idea to change the intake gaskets. if the intake gaskets were reused, I would change them out just in case.

 

good luck

[ShockTherapy]

and while the 3.1 and 3100 are similar, no your service manuals might give you the idea, but no, they won't really help you...

[supreme_style21]

I've seen those Bosch plugs alone cause most of the symptoms you describe.

[GP1138]

Werd, get rid of the Platinum plugs. They're terrible in these engines.

[gp90se]

Werd, get rid of the Platinum plugs. They're terrible in these engines.

 

plats run fine, its the bosch that have issues. we ran plat ngks in a 3100, 50k no problems

[GP1138]

*sigh*

[gp90se]

show me proof plats in a 3x00 dont run well

[Prospeeder]

show me proof plats in a 3x00 dont run well

 

 

umm aout 99.9% of people who use them have problems, proof enough?

[gp90se]

show me proof plats in a 3x00 dont run well

 

 

umm aout 99.9% of people who use them have problems, proof enough?

 

A) you run a turbo 3.1, not a N/A 3x00 motor, different beast

contribute facts rather then pulling % outta your rear

C) proof, 1 word, not saying im not right or wrong, i wanna see proof

[GP1138]

It's not a matter of guessing, or proof, it's a fact. I don't know how you managed to get 50k out of them, I was told this in my auto performance class, and it's common sense, you run platinums in a waste spark ignition system where three cylinders are firing reverse polarity, you get three plugs that wear REAL fast.

 

The problem that Bosch has acknowledged when using their Platinum plugs

in engines with waste spark ignition systems stems from the tendency of

electrode metal to get transferred depending upon the polarity (direction

of current flow) of the spark. In waste spark ignition systems, 1/2 of the

plugs always see reverse polarity sparks. Given the very narrow platinum

center electrode of the Bosch Platinums, performance will be degraded more

significantly when reverse polarity sparks will cause material to be

transferred from the large ground/outer electrode onto the narrow platinum

center electrode's exposed end surface.

 

http://au.geocities.com/ozbrick850/engine-sparkboschplat.html

 

There's one link. Obviously not 100% GOSPEL truth, but why in God's name would a professional who WROTE my Goddamn auto textbook tell me something that wasn't a fact, and that can be corobborated elsewhere?

[gp90se]

These plugs were designed for OE (Original Equipment) DIS usage. The spark plug fires on the compression stroke and on the exhaust stroke, so it fires twice as often as it did in the conventional Distributor Ignition System. In addition to the platinum electrodes, this spark plug is engineered to meet the demands of the OE design for heat range and gap setting. The Autolite® Double Platinum spark plug design maintains optimal performance longer.

 

 

http://www.autolite.com/framer.cgi?page=http://www.autolite.com/products/dis.htm

 

plugs have changed over the years to accomodate (sp?) DIS systems

[Canada]

Platnium isn't the problem here.....Bosch is. The AC Delco platnium plugs sure as hell work fine.

 

I don't know why someone wouldn't replace the lower intake gasket.......I mean, when doing a head gasket, the intake manifold is taken off........its not like those gaskets are useable. Although I would look for error in his work......however, if he was having the same problem before the headgasket job....then should be able to find it.

 

I'd check to make sure you had spark on all the cylinders.....you can get a HEI spark tester from O'Reily's for like $3. I would also replace the plugs.

 

Then, I would check fuel pressure.......and fuel flow.....most pressure gauges have a pressure dump on the side.....with the engine at idle, it should still be able to run witht he pressure relief depressed. I've seen plenty of pumps make enough pressure, but not enough flow.

 

Then, check the injectors.....I doubt you have the GM breakout box.....so you are going to have to do the next best thing......ohm check each injector.....you don't have to pull off the intake manifold if you don't want.....you can do it at the connector for the injectors.

[gp90se]

Platnium isn't the problem here.....Bosch is. The AC Delco platnium plugs sure as hell work fine.

 

 

Thank you

 

 

I don't know why someone wouldn't replace the lower intake gasket.......I mean, when doing a head gasket, the intake manifold is taken off........its not like those gaskets are useable. Although I would look for error in his work......however, if he was having the same problem before the headgasket job....then should be able to find it.

 

If he did reuse the intake gaskets, I would change them regardless, the lowers never seem to seat right again and become very prone to leaking.

 

either way, change the plugs first and see how it does.

[SigEpCutlass]

anyone bother to check the coil packs? i had a spark problem due to them rusting. I replaced them, got new wires & plugs, and i was golden. i'm not as good technically as some of these guys, but you might want to consider that.

[sdwhite]

I've been pulling my hair out wondering why none of this has helped. The Bosch plugs are coming out tomorrow.

 

I changed the fuel filter today...was an AC Delco...been on a long time. Couldn't possibly be original, could it?

 

Anyway, it didn't make any difference in how it ran. I put in a can of Sea Foam top engine cleaner...little puffs of white smoke happily coming out of the exhaust.

 

I tried to check for spark. I'll have to get the HEI spark tester when I get the new plugs tomorrow morning.

 

How difficult is it to change the bottom intake gasket? previous owner was obviously a dufus and prolly screwed it up. That might be my whole problem right there.

 

Thanks for all the help

 

Scotty

[ShockTherapy]

it's not too hard to do.

[supreme_style21]

I put in a can of Sea Foam top engine cleaner...little puffs of white smoke happily coming out of the exhaust.

 

Scotty

 

Where did you put the Seafoam? It isn't a 'top end cleaner' persay, but works rightfully so.... the puffs of white smoke are either good or bad, depending on where you put the stuff.

[sdwhite]

Put it in the fuel tank. I figger it's cleaning out the carbon. On carbureted engines it says to pour 1/3 bottle slowly down the carb & kill the engine...let it work it's magic for a few minutes and start it back up. Buku smoke out the tailpipe.

[supreme_style21]

Put it in the fuel tank. I figger it's cleaning out the carbon. On carbureted engines it says to pour 1/3 bottle slowly down the carb & kill the engine...let it work it's magic for a few minutes and start it back up. Buku smoke out the tailpipe.

 

:? I couldn't see how it'd make the exhaust smoke white unless you were REALLY damn low on fuel.

[sdwhite]

There's only about 5 gallons in the tank.

[sdwhite]

Head gaskets were just changed and there's no oil in the coolant & vice versa.

[slick]

Did you change the plugs out yet? How do your plug wires appear?

 

Exactly what symptoms does it have. You said it idles poorly, and dies at times. When it runs, does it run smootlly(although lack of power), or run rough? How does the engine sound?

 

If you haven't already, get those plugs and plug wires changed. I would not rule out the coil packs/icm either.

 

If you want to check the lower intake gasket, get some carb/tb cleaner, and spray it at the lower intake gasket while the car is running. If the idle fluctuates, you know whats wrong. But, there is no coolant in the oil, so most likely this is fine.

 

I'd toss in more fuel, as the 5 gallons you have in there, plus the stuff that was in there previously may not be enough to get that old crap out. Adding a lot of fresh, new gas might help some.

[sdwhite]

New plugs & wires. Idles very rough. Put it in gear and it dies, mostly...feather the pedal and you can get it to go. Haven't ruled anything out yet. Per comments here, I'm getting rid of the Bosch 2 platinums.

 

I tried the carb cleaner trick but the idle is so rough to begin with I didn't notice any change.

[sdwhite]

I wonder if these things ever jump a cog on the timing chain? Do they stretch out? I wonder what the life expectancy is on them...never thought about that before.