I have a 96' monte carlo with a 3.1 in it. The car runs fine for a couple of minutes while its cold. Once it warms up its runs like crap. There is no power at all and feels like it is running out of gas when trying to accelerate. I changed the fuel filter on it and drove for about 4 miles with a fuel pressure gauge on it which read 40psi all the time. I also put new plugs, new wires, new air filter on the car and even changed the oil just for the heck of it.... The check engine light is off but i still had advanced auto run it on their handheld computer thing and everything came back fine. The car idles fine (850-900rpm) even when it is warm but there is a sputtering sound coming from the tailpipe. .. I'm at wits end on this one, only thing I can think it might be is the catalytic converter or maybe the timing chain is stretched.... I would like to hear from someone who might have a little more knowledge on this.
Car has 160k or so miles....
Intake gaskets? Them cars are well known for that, clogged cat would be a good question, lob it off n haul it in lol them engines sound sweet without cats
plugged cat is a good start... the 3.1 you have is also kown for head gaskets blowing, usually the rear center from what i've seen, how's compression??you getting any coolent in ht eexhaust? or in the oil??
There is no antifreeze leaking or in the oil. The antifreeze level always stays constant, Ive never had to add antifreeze and have never had the low coolant light ever come on. Im going to start with the cat first and go from there. I havent done a compression though, about what compression should I have?
i think with that motor it's supposed to be 160 to 180 psi.. but it's been a while since i messed with those motors
Well i changed the cat out today and put in a straight pipe, the cat was plugged, I held it up to a light fixture and could just see one little spot of light through it... the car seems to run 90 percent better after doing so, but sometimes it will hesitate then be just fine. It has never done this. I added some injector cleaner and 10gallons of premium gas (there was probably 3 gallons or so of the old stuff still in the tank) and the hestitation seems to be going away the longer I drive the car. I think I may have gotten some bad gas. I stopped at one of those wal mart gas stations (murphy usa) and filled it up monday of last week and since tuesday of last week I have been having problems. Ill keep you guys posted. Anyone else ever had any problems with gas from one of these places? I got gas in Clio, Mi. and thanks for the help everyone.
Quote from: fabizpwn on November 22, 2011, 01:58:38 AM
Well i changed the cat out today and put in a straight pipe, the cat was plugged, I held it up to a light fixture and could just see one little spot of light through it... the car seems to run 90 percent better after doing so, but sometimes it will hesitate then be just fine. It has never done this. I added some injector cleaner and 10gallons of premium gas (there was probably 3 gallons or so of the old stuff still in the tank) and the hestitation seems to be going away the longer I drive the car. I think I may have gotten some bad gas. I stopped at one of those wal mart gas stations (murphy usa) and filled it up monday of last week and since tuesday of last week I have been having problems. Ill keep you guys posted. Anyone else ever had any problems with gas from one of these places? I got gas in Clio, Mi. and thanks for the help everyone.
your o2 at the cat is probably reading crappy since there is no cat now. I have an aftermarket cat in my 01 grand prix and it throws a code all the time.
Quote from: ProGrade on November 22, 2011, 06:31:04 AM
Quote from: fabizpwn on November 22, 2011, 01:58:38 AM
Well i changed the cat out today and put in a straight pipe, the cat was plugged, I held it up to a light fixture and could just see one little spot of light through it... the car seems to run 90 percent better after doing so, but sometimes it will hesitate then be just fine. It has never done this. I added some injector cleaner and 10gallons of premium gas (there was probably 3 gallons or so of the old stuff still in the tank) and the hestitation seems to be going away the longer I drive the car. I think I may have gotten some bad gas. I stopped at one of those wal mart gas stations (murphy usa) and filled it up monday of last week and since tuesday of last week I have been having problems. Ill keep you guys posted. Anyone else ever had any problems with gas from one of these places? I got gas in Clio, Mi. and thanks for the help everyone.
your o2 at the cat is probably reading crappy since there is no cat now. I have an aftermarket cat in my 01 grand prix and it throws a code all the time.
x2
yupp what they said, i was able to take the cats off my 93 grand marquis because there was only a PREcat o2, on my grand am gt (same engine as yours) i straight piped it, but i had to get an o2 simulators, and i wouldnt of had it but a buddy had it from a car he had done. they are pricey for a simulator but it keeps your computer happy.
I usually try to stay with speedway or marathon when it come to buying gas. Admiral is the worst. I had a 97 S-10 4 banger that I filled up from an admiral one time and it spark knocked,back fired, and lost a lot of power. After that tank was done I filled at a speedway and it slowly straighten itself out. After that I always used speedway and never had a problem.
admiral is usually the cheapest gas, and it is because it is a cheap quality,in my GTP i only run shell premium, i will go out of my way to find gas.. lol