97 F350 7.3 New problem, no throttle response

ramjo

ramjo

Well-Known Member
Joined
Apr 13, 2010
Location
Marion,NC
I've got a '97 crew cab thats giving me some trouble with the TPS, or thats what I thought (think) . I haven't had the truck too long but it doesn't seem to give me the throttle response I think it should. It sometimes has a hesitation to it and has surges at random times, or a complete nonresponse to pedal movement, then it throws the CEL. I put in a junkyard pedal with no improvement, maybe a little worse than before (complete shutoff of engine a couple times). I ordered the Dorman replacement TPS which gave a little better pedal response for the first 2 miles I drove it but still didn't fix hesitation/ CEL problem. I'm guessing the TPS wiring is tied in with some other stuff so does any body have any ideas what to check for next? :confused:
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I didn't want to start up a new thread so I will update this one

Updated info:

So I fixed the original problem, which turned out to be the ICP. I changed it out and it ran great (better than before but still no real power). Anywho, I started it up and drove it couple miles down the road to work. When I went back out to crank up and leave, fired up and immediately died. The tac is working, HPOP full, changed oil, #22 and #8 fuses good. I did change fuel filter and clean the screen out between the fuel bowl and FPR (?) which was all but stopped up. I did get it to start about 4 cranking cycles after the filter clean but nothing since. Anybody have a spare IDM laying around? Any other ideas?
 
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ramjo said:
I've got a '97 crew cab thats giving me some trouble with the TPS, or thats what I thought (think) . I haven't had the truck too long but it doesn't seem to give me the throttle response I think it should. It sometimes has a hesitation to it and has surges at random times, or a complete nonresponse to pedal movement, then it throws the CEL. I put in a junkyard pedal with no improvement, maybe a little worse than before (complete shutoff of engine a couple times). I ordered the Dorman replacement TPS which gave a little better pedal response for the first 2 miles I drove it but still didn't fix hesitation/ CEL problem. I'm guessing the TPS wiring is tied in with some other stuff so does any body have any ideas what to check for next? :confused:
Click to expand...

What code are you getting?
Have you checked all the other basics and serviced it lately?
Things to take a look at are
apps curve - does it have a smooth and gradual voltage climb as you slowly press the pedal?
Ivs circuit - do the Ivs pids change the the pedal is pressed?
Cylinder contribution test?
Injector buzz test?
Fuel pressure?
Icp pressure at idle and under load
Ipr duty cycle at idle and under load

That's a starting point if nothing else
 
Not sure about the code, Is it possible to check if the CEL doesn't stay on. Im pretty sure I don't have the tools to check most of the stuff you guys mentioned. I did check one of the TPS I changed out with hand held volt meter and could read a change from .6 - 3.8 from idle to WOT. From what i read it need to be in the .4 - 4.4 range maybe. I can hear the IVS "click" on and off when the pedal is pressed and released. Truck is supposed to have new fuel pump,CPS, and changed out wiring under valve cover as well. Does this stuff need to be "real time" check with a computer and diagnostics programs or other tools?
 
Anytime a check engine light has come on the code is still there. It stays as a memory or history code. It would be best to use a scanner with live data. This will allow you to see exactly what the computer is seeing. Sometimes it's the computers perception of the data that's the problem not the input itself. If not a using a scan tool IVS will be checked using a continuity or resistance test on the bench. I had a 7.3l last month that the ivs circuit had a faulty splice - causing a "dead pedal" other shops had replaced all the common parts but no one checked for voltage.
 
Still haven't had time to go check the code yet, but I did leave my parking lights on accidentally this morning for a pretty good while. The truck had no problem cranking up but wouldn't rev up past 1500 RPM. Could bad battery connections/ weak battery cause the other problem as well?
 
You'll need a little bit better scan tool. Snap on, ford's ids, otc etc. A basic code reader isn't going to cut it. Might be easiest to pay a shop a .5hr diag.
 
You'll notice that the Ford diesels are pretty picky and need a good, quality scanner like @mysterync said. If you plan to keep it for a while, it might would be worth investing in one for yourself. The one that comes to mind is Auto Enginuity...I think a guy at work has it and his has a gauge that displays whatever data you select. Seems to work quite well.

Just looked it up and it appears that it doesn't go pre-99. My bad!
 
mysterync said:
I don't know any of those...I'll keep my eye out
Click to expand...



haha.....should have clarified that statement to say: "close by with tools, who work for free". I appreciate your help so far. I haven't had much time to really mess with it, I'm doing a whole house remodel so thats where my time and money are going.




Croatan_Kid said:
Just looked it up and it appears that it doesn't go pre-99. My bad!
Click to expand...


I saw some a post somewhere where they were using it on a '97......

http://www.ford-trucks.com/forums/871902-i-got-autoenginuity-now-what.html

so it might work after all......who knows!!
 
Well, there ya go!
 
ramjo said:
haha.....should have clarified that statement to say: "close by with tools, who work for free". I appreciate your help so far. I haven't had much time to really mess with it, I'm doing a whole house remodel so thats where my time and money are going.







I saw some a post somewhere where they were using it on a '97......

http://www.ford-trucks.com/forums/871902-i-got-autoenginuity-now-what.html

so it might work after all......who knows!!
Click to expand...
I understand completely lol.
I think auto enginuity will do a generic obdII on the older models but may not off bidirectional controls and history codes etc.
 
@mysterync....... I still haven't checked this thing out with any type of scanner yet but may have located the problem. I recently drove it on 2 hour drive from Marion to Charlotte, and had no problem at all from the house to the speedway as soon as the CEL came on. Same scenario on the drive back home. My brother did a little searching and told me to check ICP (unplug it and see how it runs). I assume if defaults to a specified setting when unplugged? I unplugged it, CEL is on but runs fine( no weird herky, jerky stuff yet). Guess, I will replace ICP and go from there.
 
Updated info:

So I fixed the original problem, which turned out to be the ICP. I changed it out and it ran great (better than before but still no real power)for about a month or so. Anywho, I started it up and drove it couple miles down the road to work. When I went back out to crank up and leave, fired up and immediately died. The tac is working, HPOP full, changed oil, #22 and #8 fuses good. I did change fuel filter and clean the screen out between the fuel bowl and FPR (?) which was all but stopped up. I did get it to start about 4 cranking cycles after the screen clean but nothing since. Anybody have a spare IDM laying around? Any other ideas?
 
I assume I need a scan program for that?. I think I will hit a local shop up and see if he has something to do that with.
 
Had a local boy let me borrow the IDM out of his truck and it fired right up! I got one out of a '99 at the junkyard and I'm back on the road again. Any ideas on what cause IDM failures?
 
The biggest issue I've seen is moisture. Over time the sealer looses it seal and moisture and road grime get in it. Other issues like valve cover harnesses may help shorten it's life, but if it's never had one itay have just been that time.
 
I think it was a reman'd one. I need to tidy up some of the valve cover wiring, somebody hacked into it before. i think I'll open it up and see what it looks like. Those things are to pricey to throw away!
 
Oh yea, that was the plan! I've been reading about changing the resistor out to bump it up to 140. Not sure what all that means, haha What else can you do to them?
 
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