3800 Series Stumper

[AdamWGregg]

Car:
1999 Buick LeSabre Custom
3800 Series V6
90K miles.
Fresh plugs and wires.
(no previous issues in the past year)

So, this is a doozy and it's got my dad and me STUMPED!

driving back to work after lunch about half a mile away the car starts flashing the CEL and starts missing like crazy. I thought it was going to die, but it didn't. I got into the parking lot and parked. the car never stopped even at an Idle, but it was VERY rough. I turned the car off and started it again, it started but stayed super rough.

I went in to work and came back on break about an hour later and the car wouldn't even turn over. I went back inside and my dad came to check it out. he came and the car wouldn't turn over. jumped it and then it seemed to have gotten "unstuck" car turned over and over and nothing. since that one jump the car has been turning over fine on the battery alone (battery in quite new BTW)

Checked:
1. fuel pressure is good
2. spark - seemed pretty weak but it was there
3. engine code was P0300

all of the wires had equally weak spark, so we went and bought a ignition module. replaced that and got more of the same, but the spark was a lot brighter, more blue now than red. spark was very consistent as well.

car turns over good and hard.
air is being pulled in the intake and pushed out the exhaust.
fuel seems to have good pressure.
wire connections are corrosion free

pulled the MAF sensor - no change
pulled the crankshaft sensor - no change
pulled the cam shaft sensor - no change.
pulled the intake hose off and checked the MAF and it opened and closed freely (the air seemed to push back just as I stopped trying to start the car)

erased codes, and it won't give us another one.

so, all i have is a car that turns over and over with spark, fuel and air and just won't start.

any ideas would be MUCH appreciated

[HotZ28]

Originally Posted by AdamWGregg

I pulled the MAF sensor - no change
pulled the crankshaft sensor - no change
pulled the cam shaft sensor - no change.
pulled the intake hose off and checked the MAF

Pull the plugs & take a look for signs of coolant on the plugs. In addition, turn the engine over with the plugs removed to see if it pumps coolant from the combustion chambers. Your symptoms sound a lot like the the typical UIM/EGR meltdown! Click Here for more details.

[AdamWGregg]

wow, that sounds like a pain in the ... lol.

thanks for the reply, however i do have a question:

while driving it the 3 or 4 minutes that i did i didn't notice any steam or smoke or anything coming out the back, wouldn't it have given some kind of exhaust craziness?

I'm really not sure,

but thanks,

I'll pull the plugs tomorrow. the car is still at work.

anyone else agree/disagree? i just wanna get all the replies i can before i go back to work.

thanks again and in advance!

-Adam

[AdamWGregg]

I pulled the spark plug and turned her over, nothing came out and i didn't smell antifreeze.

if it is that issue would the antifreeze be in ALL of the cylinders? or could it be just a couple?

[Rasp]

It is possible it is only in 1 plug. and it could be a plug from the back of the engine. You should take all the plugs off and do the test.

But another question first. have you noticed coolant leaking or I should say being used. When my Upper intake went I didn't see an external leak but I did see that antifreeze was being used.

I also didn't see white smoke billowing out of the exhaust at first. I think my leak started very slowly and quickly progressed to a fast internal leak.

BTW I will add that if it is an upper intake manifold issue, you could do the job yourself. I did mine and I don't by any means consider myself a pro. The trick is to label everything.

[AdamWGregg]

There IS a leak in the front of the intake manifold. there has been since i got the car. I've had it a year and it might have used a TOTAL of a couple liters in the whole year.

it has been so small that i didn't really pay much mind to it.

if i get a replacement will it do the same thing?

there is a 3rd party part that claims to resolve the issue that seems to be so well known.

will any replacement part be better than the factory?

[pcmos]

I can't really elaborate right now because I'm at work and in the middle of a few different assignments. I noticed your post and had to jump in. Check the spark with an inline spark tester (Approx. $3 Harbor Freight). Move the tester to every plug location and run the engine. If you find a dead spark with the tester, don't immediately suspect the coil pack. Swap the packs on the Ignition Control Module and see if the problem moves with the coil pack or stays in the same location. If the problem stays in the same location, replace the Ignition Control Module itself.

I had the exact, and I mean exact, failure on my 2004 recently. Please avoid buying an AutoZone or aftermarket brand ICM if it does turn out to be the problem. They are total junk, I went through two of the AutoZone ICM units before finally just buying an AC Delco part on RockAuto.com. If the ICM or one of the coil packs is to blame, it's really easy to fix and you'll notice an immediate change when you restart.

[AdamWGregg]

thanks PCMOS

i did check all of the wires by pulling it and observing the spark and they all spark the same. so i'm not sure if it's the same. I'm gonna be working on it this weekend and i'll update.

Thanks GUYS!

[Anthonyz]

Try pressurizing the coolant system and leave pressure on for several hours. Leave the spark plugs out and turn the engine over and see if coolant shoots out of one or more of the cylinders. These engines have problems with the plastic intake manifolds. Good luck. Anthonyz [email protected]

[pcmos]

The flashing MIL is the PCM's way of indicating an on-going or continuous misfire condition. When the MIL illuminates and then flashes periodically, the computer is warning the driver that the misfire condition may cause severe damage to the catalytic converter. If you were to diagnose the system with a GM enhanced scantool like the factory Tech II or the AutoEnginuity system I have, you would see constant misfires on one or more cylinders.

Unfortunately, removing the plug boots and checking for a visible spark is not a valid test, not to mention potentially very harmful to the onboard electronics. The inline spark tester illuminats whenever the secondary coil is discharged to ground. This includes wire shorts, carbon tracked plugs, fouled plugs, etc. Any time there is potential on the secondary coil and it is grounded through the inline tester, the tester will illuminate. This is important because if the tester ever fails to illuminate, its virtually gaurunteed that there is no power at the coil. 99% of the time, worn plugs, shorted wires or anything else will still cause the inline tester to illuminate as long as the coil is powered because the high voltage potential usually finds some path to ground.

In order to properly diagnose an ignition concern you should install the inline tester, start the engine and watch the test light for an extended period of time (3-5 minutes per cylinder at least). If you install the inline tester and follow the afforementioned procedure, you should always see a consistent pulsation of the test lamp. Any pause or periodic loss of the test lamp illumination is an indication of an ignition fault. There really isn't anything to lose by trying, the tester costs about 3 or 5 dollars.

Loss of test lamp illumination only indicates that there is probably no potential building on the secondary ignition coil in the transformer pack. This car uses three ignition transformers (commonly called coil packs). Each transformer has two secondary coil taps where the potential is equal at the time of a spark event. Spark plugs ignite simultaneously in pairs and only one of the plugs is firing in a loaded cylinder under compression, the other "wasted spark" fires on a cylinder in its exhaust stroke. Because of the interconnects and coil taps it is possible, but unlikely, for only one post to be dead on a two post coil pack. Be sure to check all six wires for proper spark.

If you aren't losing coolant, and the event occured very suddenly, the problem is almost surely related to ignition. The coil packs are about $50 each and the ICM that drives the coil transformer packs is about $250 for an AC Delco brand unit. Hope you are able to get it straightened out.

Please remember that if you disable spark on a cylinder during diagnostic procedures, the computer is still energizing the fuel injector for that cylinder. In general it is a good idea whever you disable the spark on a cylinder, to also pull the plug for the injector in order to protect your catalytic converter.

[Mickey#1]

If it's still not turning over then you need to remove all the spark plugs. If it's turning over but not starting then you can pull the air intake off & check for coolant. If you keep trying to start a hydro-locked engine you could break the starter or maybe even bend a rod. You're actually better off if you put a wrench on the crank or alternator & see if the crank turns. A hydro-locked engine will turn counter clockwise but not clockwise.

[stripe]

I had a case where I had purchased bad gasoline.
(some diesel mixed up with gas)

It caused much the same problem.

Cheers
Stripe

[AdamWGregg]

I GOT IT WORKING!!

so the intake manifold WAS the issue.

got a new one and all is well now.

we DID have some issues with the fuel rack sitting right with the injectors. we had all the injectors sitting in the manifold and then put the rack on then, lined them up and after some convincing, they were all seated and clipped.

then we spent 10 minutes turning her over, little did we know that an O-ring on the injector was torn spraying fuel all over the motor. we pulled a plug to make sure that there wasn't any more coolant in the cylinder. the plug wire arched and lit the fuel on fire. that was fun.

after that was put out, we got the o-rings replaced and used some boot lube to let them slide in easily to the fuel rack and clipped them in place. then sunk down the injectors into the manifold, that worked much better.

we turned over the car again for a few minutes and she finally started.

10 minutes of steam and a drive around the block and she ran fine.

changed the oil this morning and had an injector cleaning done went to Walmart and got an oil change and injector cleaning for $45 they were running a special.

so all is well i believe.

THANKS FOR EVERYTHING GUYS!!

[HotZ28]

Thanks for the feedback & glad to here you got it running again. With all that crap in the exhaust system, your cat may need replacing, which is a preventive maintenance item anyway, with 90K on the clock!