It's a SOHC in a 94 Grand Marquis. when starting up cold it acts like its going to cut out for a moment then will rough idle until warm. if you give it any gas it acts like its running on 2 or 3 cylinders and sputters and if steadily held at 2500+rpm it will begin to backfire through the intake. If you pull out and actually drive it for a couple minutes you can floor it and after sputtering and struggling it might go 10mph max. after warm though it runs pretty good. engine light on right now. I was thinking possibly TPS but I'm not sure how to test it w/ my meter. or could it be MAF. There are no vacuum leaks and everything else on the motor is in good shape, it only has 70k.

 

You need to get it scanned. It could be many things. It sounds like the O2 senser may be bad but I'm just guessing without a scan.

 

Check out crownvic.net, since its an OBDI system it will be a bit more of a PITA to diagnose with the code. I'd guess its on the fuel side but don't know what would be fixing itself when it gets warmed up. I'd start with a full tune up if it hasn't had one and go from there.

 

Some 94's are actually OBD-II. My nieces 94 4.6L Cougar is. Sounds like a misfire problem. See waht the codes are and post them here. Then we can give you better info on how to repair it.

 

Thunderbirds and Cougars with the 4.6L were the only Ford products that were OBDII in '94-'95.They were the testbad for the new OBD system.
JL

 

Close, but no cigar. The 94.5-95 Powerstrokes were OBDII.

 

Ken,I can play the same game and search for your username's posts too.
The subject here was in reference to a gasoline vehicle. That was my answer-I'll verify the powerstroke personally.
JL

 

If you take a moment to search on the forums, I've been all over this morning answering threads not just one's you're in.

 

94 should be ODBII. I have a 95 Crown Vic is definetly ODBII. When I need to get it scanned I go to Autozone, they scan it for free, but only for 96 and newer. So I just tell them it's a 96, they plug in and it works. It's easier to just tell the kid it's a 96 than to try to explain that it's actually OBDII and thair scanner will work.

My 95 just got wrecked, I'm parting it out. Do you need anything?

 

94 Mustangs with a V6 are also OBD-II. I replaced a PCM in one that had a stuck open injector driver. The V8's were OBD-I until 96.

 

i'm goin out shortly to take a look at it, just don't think o2 sensor. unless that one is constantly in loop upon ignition, it shouldnt effect it while cold since it hasnt reached the proper temp. to go into closed loop.

 

well tps is good. got a code 13 as well for rpm at idle out of limits. she said it hadn't had a tuneup so i'm going to do plugs, wires, fuel filter, etc on it monday and go from there.

 

I would say find what code it has and go from there.

 

well, did the tuneup. missfire is gone but engine still is cutting out and wont rev, car wont go over 5mph so i'm about set now on it being the cat/s. gonna pull the pre-cat sensors out tomorrow and see if i can tell much of a difference.

 

I am guessing that you have verified fuel pressure?? 30-35 @idle and 38-42 with no vacuum to the regulator.