Hey everyone!

I am new here and have spent the past several days going through threads to try and diagnose the problem i am having. First the specs:

99 F250 - 7.3 - 190K - Superchip Tuner set on Tow/Haul - AFE Intake Filter Kit. Regular maintenance and service

This is my wife's truck and its current job is to stay hooked to our three-horse gooseneck. She is a horse trainer and the truck is her work truck and is rarely driven in town anymore.

Three weeks ago she called and described the following event. She was pulling the trailer and had a sudden loss of power coupled with vibrations, jerking, etc. The truck would idle, but would not rev in park, neutral or drive. Additionally the CES light did not come on. She got the rig to the side of the road, shut it down, and waited for a few minutes. She fired it back up and the problem was gone. I called a mechanic buddy and he said that it was probably the CPS, which was last changed 90K ago.

I of course got busy with work, life, and kids and forgot about it until last Saturday. The same event happened again. Loss of power, jerking, vibrations, no CES light, etc, etc. (I drove it on Friday to pick up some equipment without the trailer and it did fine even in stop and go traffic in town). On Sunday i picked up a CPS at the local store and installed it.

Monday comes and it happens again. Except this time it is accompanied by a metallic pinging sound from under the hood, and it doesn't go away after a shut down and restart. She manages to limp it home.

I read the entire thread regarding the UVCH and these are my results:

I to C - All readings between 3.1 and 4.1 ohms

G to Ground - All readings between 0.3 and 0.5 ohms

They look to be in spec.

I called my mechanic buddy back and he said that it needed to be buzzed. I don't have the technology currently but any help with links to additional threads or direction would be appreciated (i may have been using the wrong keywords in my searches). This truck needs to last us another 100K at least.

Thanks in advance for any assistance.

 

I had the EXACT identical problem in my late 99 that I used to have.

The problem resolved itself when I threw the Superchip tuner in the garbage.

 

Step 1 - pull any tuner off, or reprogram back to stock tune.

It is possible to get a good reading from a UVCH, yet have it work it's way in and out of being connected due to vibration - but you usually get an SES with a loose UVCH... usually.

This could be low oil level, or low fuel level with a bad pickup foot. What are your fuel and oil levels?

 

Sounds like mine about 4 yrs ago. My fuel pump was on its way out. Would work fine one day and happen the next day. Also ur fuel tank screens could be clogged.

 

Good call Pit, I wouldn't discount the clogged fuel pickup either. Could be debris is getting sucked up while driving, and when shut off it drops back down just to be sucked up again later.

 

Ok. Thanks for the start.

Oil level is perfect and the oil is clean.
The bowl is 100% full of fuel.

I took the program off, putting it back to stock and took it out for a drive. I am sure my experience was different than my wife's since i didn't have 8K on the back end.

I had to push the pedal half way to the floor to get any progress. There was no response from the throttle until that point. Between 2000 and 2500 rpm the thing must have felt like it was bucking due to the weight of the trailer. The reality is it felt like the power just cut out in spurts. Up to 2000 there was steady acceleration (except for the pedal being on the floor).

The "metallic pinging" my wife heard sounded like a miss to me. It actually sounded more like the rods in an old gas motor on bad gas pulling a steep hill. The sound was not constant though. It was intermittent, just like the power loss.

I would be surprised if it was a fuel thing, but i don't know all that much about diesels. Most of my experience is with late 70's F150's and 250's with gas motors.

 

Well more info always helps in troubleshooting. You said you had a dead spot on the throttle, that would leave me to guess you have a bad TPS but a bad TPS wouldnt cause bucking or vibes you just have no response. I think you might have 2 problems going on and fuel could diffidently cause your bucking and vibes that you still have.

 

Everything you described could be explained by low ICP or fuel starvation. Try pulling the ICP sensor connector off, then go for a test drive.

 

So I pulled the lead to the ICP (thanks for the diagram). Both problems are still there but the stall is not as pronounced. It still feels like you have to mash the pedal to the floor to get it to move.

 

Is the IPR tin nut securely on the end?

 

Yes, the nut is tight.

 

you mentioned, "bowl" is full. But, where's the level in the tank?

Was the connection oily, that you unplugged?

not sure when FORD replaced the go-pedal, to where you have to buy thee entire pedal assy, but see if you can unplugged the sensors and clean them up.

 

When I pulled the ICP plug off it was oily. I was surprised to see that.

I will check the pedal assembly this weekend.

Do you guys kniw if there is anyone on the forum in Boise that has the program to buzz the system?

 

Click the B.E.S.T. link in my signature.

 

Sorry for missing one question on the last post. I was doing that one on my phone.

The tank is full.....it was filled right before this started happening for the last time.

Looks like the closest members with the AE package are 150 miles away in Twin Falls. Not sure if i am going to chance taking it that far.