Ford Power Stroke Nation banner
1 - 20 of 28 Posts

·
Registered
1997 F350 power stroke
Joined
·
19 Posts
Discussion Starter · #1 ·
Hey Y’all I could use some help. I just bought a 97 7.3 and I have two issues that need to be addressed. First and most important is that when I am driving it down the road some times I lose power and the “wait to start” light comes on I lose RPMs and speed but all other gauges stay the same so I don’t think it’s electrical? As soon as I let of the pedal and give it gas again is comes back alive. I don’t think it’s the CPS sensor but I could be wrong. I also did a voltage check on my MAP sensor and it looked fine. The truck is chipped and I read somewhere else that it could be that the chip is loose so I will try that first.
The other issue I’m having is that at higher RPMs I feel a slight vibration in the pedal and it almost sounds like my fan it hitting something slightly but I checked and can’t see that it’s touching anything. Almost sounds like a valve loose or something. Open to any advice. Thanks ahead of time!
 

·
Registered
Joined
·
3,527 Posts
Definitely check the chip, but don't do it with the key anywhere near the ignition!!!! The sudden cut-off is also a symptom of a failing CPS. They are fairly cheap enough now to just try a new one and if it doesn't solve the problem, you have a spare for the glove box (always a good idea anyway). Use OEM (Ford/Motorcraft) only for sensors on these trucks. Just a note on the MAP for 94-97 trucks: They output a variable frequency signal instead of a variable voltage (as do the 99+ trucks) with varying pressure. Is your truck a 5-speed or Automatic? Cheers!
 

·
Registered
1997 F350 power stroke
Joined
·
19 Posts
Discussion Starter · #3 ·
Definitely check the chip, but don't do it with the key anywhere near the ignition!!!! The sudden cut-off is also a symptom of a failing CPS. They are fairly cheap enough now to just try a new one and if it doesn't solve the problem, you have a spare for the glove box (always a good idea anyway). Use OEM (Ford/Motorcraft) only for sensors on these trucks. Just a note on the MAP for 94-97 trucks: They output a variable frequency signal instead of a variable voltage (as do the 99+ trucks) with varying pressure. Is your truck a 5-speed or Automatic? Cheers!
Noted! It’s a Automatic. I removed the chip and no issues so far. I’m going to drive it for a few days and see if that was the fix but I will let y’all know! Still can’t put a finger on the knocking noise I’m getting. I’ve found that it only does it after the truck is warm and turning to the right makes it louder and it’s even worse when putting it in revere and turning right. Almost sounds and feels like my fan is hitting something but I know that’s not it.
 

·
Registered
Joined
·
3,527 Posts
Might check for a cracked flex plate. They like to crack around he center hub. Cheers!
 

·
Registered
Joined
·
7,061 Posts
Post the video up on a hosting site such as YouTube and then post the link to it here.
 

·
Premium Member
99 & 00, F350s, manual and auto, Ext & Crew Cab, 4x2 & 4x4, need more room!
Joined
·
3,480 Posts

·
Registered
1997 F350 power stroke
Joined
·
19 Posts
Discussion Starter · #14 ·
Hey Y’all I could use some help. I just bought a 97 7.3 and I have two issues that need to be addressed. First and most important is that when I am driving it down the road some times I lose power and the “wait to start” light comes on I lose RPMs and speed but all other gauges stay the same so I don’t think it’s electrical? As soon as I let of the pedal and give it gas again is comes back alive. I don’t think it’s the CPS sensor but I could be wrong. I also did a voltage check on my MAP sensor and it looked fine. The truck is chipped and I read somewhere else that it could be that the chip is loose so I will try that first.
The other issue I’m having is that at higher RPMs I feel a slight vibration in the pedal and it almost sounds like my fan it hitting something slightly but I checked and can’t see that it’s touching anything. Almost sounds like a valve loose or something. Open to any advice. Thanks ahead of time!
UPDATE I fixed the issue with the truck losing power going down the road and getting the what to start light. It was because of the tuner or chip being loose. I am still currently trying to diagnose what knocking noise I am hearing. It sounds like a cracked flex plate but now I have someone saying it may be the IDM. The only reason I’m skeptical that the flex plate is broken is because it was just installed a couple of weeks ago with the new transmission.
 

·
Registered
1997 F350 power stroke
Joined
·
19 Posts
Discussion Starter · #16 ·
i would still inspect it, new does not mean good.
lately i replace more "new" parts than you could ever imagine before finding a good one.
When you say inspect it does that mean pull it all the way out? I pulled the cover off yesterday and couldn’t see anything by I know they crack closer to where they mount which I can’t see. Someone said it could be the IDM
 

·
Premium Member
99 & 00, F350s, manual and auto, Ext & Crew Cab, 4x2 & 4x4, need more room!
Joined
·
3,480 Posts
i would still inspect it, new does not mean good.
lately i replace more "new" parts than you could ever imagine before finding a good one.
Me, too. Chinese crap.
 

·
Premium Member
99 & 00, F350s, manual and auto, Ext & Crew Cab, 4x2 & 4x4, need more room!
Joined
·
3,480 Posts
grab the ring gear and move it block to trans and see if it moves. it should be solid with no movement at all.
you can not tell by just looking at it.
Not in just one place, either. Mark the bottom with one streak, with something like a grease pencil or soap stone. Then turn it over, and see if it moves in another. Mark that place. Continue until you have tested at least four quadrants.
 
  • Like
Reactions: 1970something
1 - 20 of 28 Posts
Top