97' Buick lesabre will start but will not stay running.. HELP ME !!

Hello,
I have a 1997 Buick Lesabre 3.8 auto with under 120k on it.
I have replaced the intake gasket roughly 3 years ago.( cheap plastic piece of crap I might add ! )
Well recently it started acting up so I took it to a buddies shop to have it diagnose don his hand held. ( was running a little "off" and acted sluggish, check engine light and ABS light stayed on )
Well he found a code and cleared it. No lights came back on after wards nore are they now with the current problem. He said the code indicated a vacuum leak. We both checked the lines and found nothing. I asked if it could be the intake gasket I replaced 3 years ago myself and he said he doubted it.

So Today I was on my way back from the local pets store and I sarted and immediately died in the parking lot. I tried several times and smelt a gass like rotten egg smell. I let it sit for a few minutes, got out and checked for cracked hoses and bad connections. Found none. Then I discovered if I fesather pumped the gas pedal it would stay running as long as I was feathering it out BUT if I let off it immediatel dies.
As well all the while I am feathering it to keep it running it acts like it is dropping cylinder sor something, maybe not getting fire, or fuel ?

Now I dont know if this is a coincidence or not but we got cheap UDF gas shortly before this happened.

The plugs are over due for a change and I am sure the fuel filter needs it by now as well. ( I dont think it has ever been changed actually ? )

What does the problem sound like to you guys ?
THANKS !!

Duane

Wow rotten egg smell sounds like the Cat
Put a new pcv in and make sure you have both O rings

Hello,
I have a 1997 Buick Lesabre 3.8 auto with under 120k on it.
I have replaced the intake gasket roughly 3 years ago.( cheap plastic piece of crap I might add ! )
Well recently it started acting up so I took it to a buddies shop to have it diagnose don his hand held. ( was running a little "off" and acted sluggish, check engine light and ABS light stayed on )
Well he found a code and cleared it. No lights came back on after wards nore are they now with the current problem. He said the code indicated a vacuum leak. We both checked the lines and found nothing. I asked if it could be the intake gasket I replaced 3 years ago myself and he said he doubted it.

So Today I was on my way back from the local pets store and I sarted and immediately died in the parking lot. I tried several times and smelt a gass like rotten egg smell. I let it sit for a few minutes, got out and checked for cracked hoses and bad connections. Found none. Then I discovered if I fesather pumped the gas pedal it would stay running as long as I was feathering it out BUT if I let off it immediatel dies.
As well all the while I am feathering it to keep it running it acts like it is dropping cylinder sor something, maybe not getting fire, or fuel ?

Now I dont know if this is a coincidence or not but we got cheap UDF gas shortly before this happened.

The plugs are over due for a change and I am sure the fuel filter needs it by now as well. ( I dont think it has ever been changed actually ? )

I think you need to replace the plugs with the correct AC Delco plugs. And do the wires with quality Delco replacements or another good brand is Belden from NAPA. My first thought is one of those is causing misfire which is allowing extra unburned gas through.

You could have a problem with the coils or the contacts under them.

The fuel filter might be a nice change if it's never been done. It's under the passenger rear door--but the line to it is going to be rusted from salt in many areas of the country. Use a wrench that slips over the lines that's like a box end wrench with an opening to hold the nut. The other end snaps off by squeezing the clips.

I'd replace those things assuming the least damaging type of problem here. The coils would be next to have them checked for resistance and for contact underneath. Bad wires sometimes cause coils to work harder and then to fail.

UDF gas: if that's United Dairy Farmer stores, in this area it's Mobile/Exxon fuel and it's good. Of course the station might have a problem with their tank or something.

As for the fuel, you might have an injector problem. I'd visit Walmart and buy two cans of Techron Fuel System Cleaner. They only have the 12 gallon size here so put in one when the tank is low and fill with about 9 more gallons. Drive till low. Then repeat. Buy Fuel System Cleaner rather than the Injector Clean, which I believe is weaker.

Other things would be the MAF sensor might be dirty or need replacing.

I'd check fuel pressure here also.

if there is fuel in the vaccume line to the fuel pressure regulator, replace regulator

I would look closely at that large vacuum line that hooks on to the back side of the UIM, in particular, where it connects to the UIM. Did the check engine light come back on again after starting at the pet store?

Next, I would replace the PCV valve and the fuel filter.
Then, the fuel pressure would be a good check. It might be the fuel pump. Whenever I have had a cylinder miss due to a plug wire, I always get a code that indicates the cylinder. It may not be electrical.

Cleaning the MAF sensor may help. I have two 97 Lesabres. About every 3 or 4 months, I have to clean the MAF sensor in one of them. It will cut out and start dying. Cleaning the MAF sensor corrects this for 3 or 4 months.