TCCoA Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
67 Posts
Discussion Starter #1
I've got a few issues that have developed with my car.

The car runs rough and is very bad during acceleration. I'm not sure where to start so I pulled the codes and I'm looking for some advice.

Code 1:
P0308
Cylinder 8 misfire

Code 2:
P0402
Exhaust gas recirculation flow excessive

Code 3:
P1401
Differential pressure feedback electronic sensor circuit high voltage

Code 4:
P0174
System too lean

Any help would be appreciated.

Thanks,
Ron
 

·
Registered
Joined
·
8 Posts
Not a hijack, but I have a 94 with no codes misfiring on cylinder #1 under acceleration. switched plugs to see if the miss follows the plug...no

I had the opportunity to put the car on a scope and watch the cylinders and it is cyl #1 misfiring. The techs say it was running lean on that cyl. Kinda sound similar to your problem.

your code P1401 is your DPFE sensor and is causing most of your codes, but #8 cylinder could be misfiring due to a bad EGR or stuck open.
 

·
Registered
Joined
·
171 Posts
I've got a few issues that have developed with my car.

The car runs rough and is very bad during acceleration. I'm not sure where to start so I pulled the codes and I'm looking for some advice.

Code 1:
P0308
Cylinder 8 misfire

Code 2:
P0402
Exhaust gas recirculation flow excessive

Code 3:
P1401
Differential pressure feedback electronic sensor circuit high voltage

Code 4:
P0174
System too lean

Any help would be appreciated.

Thanks,
Ron
Hey Ron,
Code one, look at plug/plug wire
Codes 2,3,and 4 are prob related to stuck EGR...with engine idling, remove vac hose from egr valve and apply 14 inches of vacuum to valve, engine should stall or run worse. If there is no change, then replace suspect egr valve. IIRC, it's a PITA to change egr valve on 94-95.

It's nice to see a fellow Mississippian in here :)
 

·
Registered
Joined
·
1,170 Posts
I've got a few issues that have developed with my car.

The car runs rough and is very bad during acceleration. I'm not sure where to start so I pulled the codes and I'm looking for some advice.

Code 1:
P0308
Cylinder 8 misfire

Code 2:
P0402
Exhaust gas recirculation flow excessive

Code 3:
P1401
Differential pressure feedback electronic sensor circuit high voltage

Code 4:
P0174
System too lean

Any help would be appreciated.

Thanks,
Ron
In your case with a P0402 you may have a failed DPFE and/or an EGR valve that is continuous letting in air. Do the vac test, as suggested, and change your DPFE sensor. There is a troubleshooting procedure to check the DPFE but if its an original I would change it ASAP no matter what.

Usually these cars will clog the EGR, but who knows. An open EGR will cause lean codes and misfires.

The lean code could also be from a clogged/malfunctioning injector, bad plug or wire or a vac leak.

If the misfire is constant after checking the above it could be a base engine issue like a broken spring, so you can do a quick compression check to see if that is the case.
 

·
Registered
Joined
·
67 Posts
Discussion Starter #5
Thanks for the help guys I'll check into the DPFE and EGR.

Rayner,

Yeah there's not many MS folks on here. Back when I was getting started on here I tried to meet up with some guys on the coast but no one showed. So I lost interest with looking for cool people to hang out and talk t-bird with locally. I only get on here to ask for help when something is going wrong. I don't even own this car anymore, its my father in law's. I've got a 94 sc 5spd that sits in the garage. It shines up nice but it has leak where the fuel sender goes into the tank so I only put about a 1/4 of a tank of gas in it.

I like Mark VIIs. Is your in nice shape.

Thanks,
Ron
 

·
Registered
Joined
·
1,170 Posts
Also, a failed EGR solenoid can cause the valve to open. At idle, pull off the vac hose from the EGR and feel for a tiny "barely" vacuum. Anything more than that means its holding the EGR open. You can also try driving around with the EGR hose plugged and disconnected and see if it makes a difference.
 

·
Registered
Joined
·
171 Posts
Ron,
Thanks for the comment on the M8. If you are needing a fuel tank, the u pull it in between jxn and byram has a bunch of tbirds and cougars...and the tanks should be about $20-30. Swap over pump and sender and you should be good to go unless it's the o ring, then it's about $10 . Got my eye on a 95 SC here in Philly, but the owner is in jail and the parents won't sell....yet.
 

·
Registered
Joined
·
67 Posts
Discussion Starter #8
tbirdguy,

I check and see about driving with the EGR line plugged.

rayner,

I've been to the pull a part yard but not lately. I don't think I need a tank. Just the O ring. But you can't buy the Oring without buying the pump. So now its $100 problem. And I've had my tank out twice. I HATE pulling that thing. I really don't drive the car at all. I took it to a car show a couple of weeks ago, but that's about it.

Ron
 
1 - 9 of 9 Posts
Top