Jump to content

'91 Grand Prix 3.1 running rough, gasoline smell. misfire?


Psych0matt

Recommended Posts

It's been an amazing reliable car, with 180k I've been driving it every day (with a few exceptions) to work and back (15 miles one way), and I haven't had to put a dime into it aside from a quart of oil because of my next thought. I drove home last monday evening normally, everything was fine. Monday evening I back it out of the driveway because I decided to drive the blazer to my parents house. I noticed it was running rough but I thought maybe it was because I jumped in and started her so quickly just to roll it 30 feet. Tuesday I jump in to drive across town and its running really rough, a little bit of smoke when I take off from sitting at a light, and the smell of gasoline. Now, the smoke didn't appear to look or smell like oil, just unburnt fuel. I grabbed a timing light and checked all my wires and I'm getting at least what appears to be decent spark from all 3 coil packs, because that was my first thought. I need to pull all the plugs, but beyond that I can't think of much until I get a chance to dig in. Anything that would just all the sudden pop up like this and not have any warning signs, but is still drivable but just rough? Any ideas?

Link to comment
Share on other sites

with out knowing too much about it....suggest vacuum leak, icm, iac tps...etc...etc (sensors should throw a code tho) check pcv valvle , may have come undone.

Link to comment
Share on other sites

I think the fuel pressure regulator gave up. Pull the vacuum line and see if there's any fuel in it.

 

Also, could be a vacuum leak. The line that goes to my trans loves to come undone.

Link to comment
Share on other sites

Early 3.1's have a problem of burning up PCM's too. I had a '91 lumina come in that ran just like that, started hard ran super rich, never threw a code. Turned out to be a bad PCM, but there were other symptoms (SES light didn't work, speedo would come and go, etc).

Link to comment
Share on other sites

well, Its currently not throwing a code (I;ll check to see that the SES light is functional tomorrow when I tear into it), but the speedo has been off since I got it, at 70mph it shows about 105 :lol: I might take it into midas/meineke/"insert favorite auto shop" tomorrow just to get their opinion, since I also have to take the truck in for an alignment

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...