97 7.3 PCM Troubles? HELP
Thread Starter
|
New User
Joined: Jun 2010
Posts: 3
Likes: 0
97 7.3 PCM Troubles? HELP
Have a 97 7.3 350 - 160K Automatic. Problem started a few months back with truck shifting from Overdrive to lower gear at highway speeds. Seemed like the tranny was going. Took it into the shop, the tranny is fine (could use attention down the road, but not a problem now). Truck kept showing codes for cam troubles. Replaced cam (although it was done as a recall this winter). Now the truck is idling rough and sometimes dies like it is starving for fuel. Tranny guy (who is a hot rod/muscle car enthusiast) suggested it could be PCM. Where is this exactly located and how hard is it to change. Anyone else having these troubles? Info would be greatly appreciated. I'm not a gearhead just a gal needing some help from experienced people! Thanks
<!-- / message -->
<!-- / message -->
<!-- controls -->
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
Where did you get the replacement cam sensor? The gray ones from Ford and the ones you get at the parts stores (Napa, AutoZone, etc) have a history of not working well, or at all. Go to Ford or International and try to get the new purple/blue colored cam sensor and see what happens (or try swapping the one you just removed back in).
On your trans issue was the problem happening when cruising or when changing lanes? These trucks have funky wiring and a burned out turn signal or brake light (don't forget the 3rd brake light on the back of the cab) can cause the torque converter to unlock sometimes.
On your trans issue was the problem happening when cruising or when changing lanes? These trucks have funky wiring and a burned out turn signal or brake light (don't forget the 3rd brake light on the back of the cab) can cause the torque converter to unlock sometimes.
Postmaster
Joined: Sep 2007
Posts: 4,195
Likes: 6
From: Medford Oregon
Welcome to FTE ...
For the rough idle stalling situation I would put the other CPS back in if you still have it. If not they buy another one as they tend to come bad out of the box.
It is not your PCM.
For the transmission downshifting issue have you checked your brake lights including the third brake light, the one at the top outside of the cab. If any are burned out replace them before anymore troubleshooting on the transmission.
For the rough idle stalling situation I would put the other CPS back in if you still have it. If not they buy another one as they tend to come bad out of the box.
It is not your PCM.
For the transmission downshifting issue have you checked your brake lights including the third brake light, the one at the top outside of the cab. If any are burned out replace them before anymore troubleshooting on the transmission.
Thread Starter
|
New User
Joined: Jun 2010
Posts: 3
Likes: 0
The cam sensor came from Ford. as far as brakelights go, there might be an issue we haven't tackled yet. It's got a flatbed on it so there might be possible lighting problems. Thank you so much for the insight! Will look into that before more tranny diagnostics.
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
If you used LED tail lights you will need to add some resistors inline with the bulbs so there is enough resistance to not make the PCM lose its mind. Someone (probably cuda_jim) has a TSB on this.
Thread
Thread Starter
Forum
Replies
Last Post
