: 95 fleetwood running rich/rough idle

08-12-11, 08:48 AM
Hi, sometimes my 95 will idle rough at stop signs/lights. It doesn't happen too often, but lately it seems to be getting worse.

Also, when the light finally changes and I get to go, it will sputter a bit and have a strong smell of gas.

Checked the codes...none set. Any ideas what it could be? if the O2 sensor was bad wouldn't it throw codes?

08-12-11, 08:58 AM
What motor?

08-12-11, 09:07 AM
LT1 5.7 liter

08-12-11, 11:12 AM
If the O2 sensor was dead or dying, it would throw a code. Also, if it's running rich all the time it will also tell you that via a code? Does the SES light flash when it's misbehaving? You could have a lazy O2 sensor that hasn't gotten bad enough to set the SES light.

It could be the MAF, too. Particularly if it doesn't do it in open loop. Maybe try some MAF cleaner? Is your air cleaner new-ish?

My '94 behaved that way most of the 3.5 hour trip home from where I bought it. The SES light would come on occasionally and go out. I couldn't find any codes. Instead of getting worse like yours, it actually cleared up once I started driving the car.

08-12-11, 11:27 AM
put a new air filter on when I got it (year ago about...)

No SES, no lights coming on, no codes being set. It's the darnedest thing and I can't find out what's causing it. lol.

08-12-11, 03:53 PM
not sure if this is related but probably could be, atleast to the rough idle...

felt around at the plugs/wires this afternoon and noticed one of the wires wasn't pushed down all the way on the boot. Pushed it in...only time will tell if that helps or not because the rough idle doesn't happen all the time...we'll see

08-12-11, 07:44 PM
Another easy test. With engine running or ignition ON, pull the vacuum line off the FPR, see if there is any gas in the line or dripping from the FPR.

08-12-11, 10:48 PM
thanks huf.

where is the FPR located...and for the record it's the fuel pressure regulator? so i can look in the book

08-12-11, 10:54 PM
C (http://www.impalassforum.com/vBulletin/showthread.php?t=245257)heck this (http://www.impalassforum.com/vBulletin/showthread.php?t=245257) out.