NASTY MISFIRING / 95 CONCORDE

95 3.5
Was misfiring under load slightly before, it has been setting for a couple-three months at a shop waiting for strut repair (had to order a new spindle). Picked it up last night and man is it running rough. Idles OK, and doesn't seem to misfire much at steady throttle, but step into it any and it misses horribly, and not steady like one cylinder is the culprit.

Acceleration is horrible, and rough. Takes forever to get up to speed. 1st thought is wires. Did put injector cleaner in it today, but only a short run home.

Thoughts?

CODES?

None. Check engine light is always on.

Then it has codes.

Check your fuel pressure yet? Weak pump could be starving it under load and lean condition will set your check engine light.

Pump is original, it's just shy of 200,000

Pull the plug wires and look for a burn hole in the side of the insulator.

Also, ck for corrosion on top of the plug itself / inside the boot. Do the same for the coil pack end . If so, replace them do not try to clean them .

PS, if the ck engine light is on there's a fault stored.

the fault is the EGR. It's been like this since I bought it years ago. Comes on after running a bit. Always has.

If its misfiring it should have a misfire code.have the codes pulled.Rocky

This is where I would start, too.

If check engine light has always been on, there may be more than one issue. Don't take it for granted that it is on due to that same ongoing issue. Get it scanned.

Advance AZ its free to scan codes.Wont be as good as reading data but its a starting point.Rocky

Being a '95,will they still be able to? Most it seems won't do a 95 and back?

I have a 2004 Intrepid (my wife's car that I HATE!!!)

When I changed the fuel pump on this car, I realized that there is NO FUEL FILTER....the fuel pump assembly uses a built in filter..

I'm currently doing a head gasket job on it. (i've ALMOST got the drivers side head off)....now that I've spent 2 days hunkered over this car, I would have rather traded it in on something else even though we're not in a position to buy a new car....

Cant remember when they went OBD 2 But I beieve it was 94 or 95.Been a long time since Ive done one.Code reader if OBD2 should read it.Rocky

Got it scheduled to be looked at this week.

Obd2 was 96

2003 3.5 concorde developed a nasty misfire when under load. All sorts of BS and head scratching until I discovered my dad put autolites in there. I about cussed him out and told him dont ever put that garbage on anything I have to work on. NGK only




most stuff has used the 'all in one' approach for the last 15-20 years now. Does cost more but it seems like the reliability has also gone up quite a bit. One fuel module replacement in my 03 Concorde , my 94 Shadow will be on pump #5 here soon.

Still has the original fpump @ 198,000 miles. Probably the culprit.

True, EXCEPT
But 1st year Neons were OBD2 in 1995



Doubt it, OBD1 cars the connector was manufacture specific and not likely these stores will have the equipment

Doubt it, OBD1 cars the connector was manufacture specific and not likely these stores will have the equipment [/quote]

Thought so.

Was the battery disconnected while at shop?? Could be the computer "relearning" itself.. Could take up to a week or so..

Seen this on GM's, not sure on mopar...

It was during the work, clock was off, and I think it went dead on them while there.

The biggest problem I saw with them was plug wires. Also make sure the plugs are ok as with 100,000 mile plugs I used to get them missfiring at 80,000 miles many times. Normally if the fuel pump is going bad it wont just feel like a missfire but will backfire and feel like the car is laying over and running out of gas. Or it will just stop running. Have someone who knows how to read a scanner check it as they can look at the adaptive fuel readings and tell if its has been running lean which is another way I could tell if the car had a fuel starving problem. But the way you desribe it to me it sounds like plugs or plug wires. Good luck , Ron

Im with 383man on the plug wires, I had a 3.5 in a new yorker and it was doing this so pulled the wires up off the plug and one had what looked like a black arc mark so I wrapped black tape aronund and put it back on which was the problem

I was getting EGR codes on my '97 Concord 3.5 It turned out to be a leaky lower intake manifold gasket. I was able to mask off all air openings at the throttle bodys, EGR, and vacuum lines and the car still ran on the air getting past the manifold gasket. Not too difficult to change out both the upper and lower manifold gaskets.