Need help with truck

[Steves LX]

I know its not a mustang but I know their are quite a few diesel guru's on here. I have a 96 F250 supercab 7.3L turbo diesel that has started to do some weird stuff. Yesterday when I left work I noticed that anytime I go 3/4 throttle or to the floor with the pedal the truck looses all power. Its like someone just turned the truck off. It stays running and doesnt actually shut off when it does this. The Wait To Start Engine light flashes and the RPM's drop to 1500 everytime it does this. Until you take your foot off the gas pedal it has no power. It's like its just idleing. Once you come off the pedal its back to normal. So I Ohmed out the TPS on the gas pedal and it appears to be alright. It wouldn't allow me to ohm it with the truck running though. The truck idles fine and runs fine throught the rest of the throttle travel. Just anywhere from right after 3/4 or to the floor it does it. I pulled my programmer off and put it back to stock and it still does this. The truck has 161,000 miles on it. The other thing it decided todo onme this morning on my way to work was. Upon taking off from a stop sign I noticed the engine sounded loud and deep like I lost my muffler or something and I had thick ass gray and black smoke just pouring out the exhaust. I stopped and took off again and the engine went back to normal sounding and no more smoke. It drove fine the rest of my 40 mile trip to work other than you cant go to the floor with the throttle or you lose all power. Any help would be greatly appreciated.

[facemelter71]

I remember an issue with one of my dads trucks being some thing close to this. I think it has to do with the wastgate opening. Let me do some digging and Ill get back to you.

[facemelter71]

Check this place out,they have helped me out before. Alot of good info there.

nevermind,I think you have to be a member to look at the threads.

Anyway,the website is Powerstroke.org

[jktruckin06]

My buddy that has multiple trucks with the 7.3 said the tps can go bad gradually. He just sold a whole pedal assembly on eBay for 40 bucks, so maybe try that? Are these the first and only 2 occurrences so far?

[Steves LX]

My buddy that has multiple trucks with the 7.3 said the tps can go bad gradually. He just sold a whole pedal assembly on eBay for 40 bucks, so maybe try that? Are these the first and only 2 occurrences so far?

Yes this just started yesterday when I left work. This morning was the first time the whole smoke issue happened and the only time that has happened. Just drove the truck up the road a little bit ago and it still wont let you go to the floor with it. Otherwise it runs fine. You can rev it to the moon with it in park and it is fine. Just under a load is when it does it. If you take off from a stop and get into it right away its fine. But as soon as it shifts into 2nd gear nothing. Cruising down the road and go to the floor and nothing until you release the pedal.

[Steves LX]

I remember an issue with one of my dads trucks being some thing close to this. I think it has to do with the wastgate opening. Let me do some digging and Ill get back to you.

Well according to some of the diesel forums these older trucks dont have wastegates. :dunno: And shit I couldn't even tell you what the hell one looks like or where to even look for it at. I am clueless when it comes to diesels and turbos period.

[facemelter71]

Im still looking for some kind of answer. Have to dig through multiple threads to find the answer Im looking for. And no one wants to answer it directly.

[Pitbull1052]

i was looking Andy and found this one........ i have no clue what the issue is just to preference this..... i was just bored and started searching to see what i could find.

http://www.justanswer.com/ford/43cx7-1996-f250-7-3-powerstroke-no-accelartion.html

[Steves LX]

Appreciate the help pittbull. My truck starts and run fine wether its cold or hot. It just goes back to idle if you go to the floor with the gas pedal while driving.

[Pitbull1052]

Np i like researching stuff like this i'll dig more..... i've read a few others and it does seem like it's the wastegate and seems like what i'm reading is telling me that the turbo has an internal wastegate.....

[facemelter71]

The PSD trucks have a problem of holding open the wastegate when its cold for warmup. And they like to do it while your driving and dump.

[adragon72]

Steve have you checked the filter? I have seen this happen to ours many times. We usually only get about 6 to 10 thousand miles depending on we're you get your fuel.

[adragon72]

Fuel filter is the one I'm receding to

[Steves LX]

No I haven't checked it yet. But I will tomorrow. I was doing a bunch of digging on this myself today and it really seems to be pointing to the computer or the IVS(idle validation switch) which you have to buy a whole new pedal assembly.

[adragon72]

Man that sounds expensive!! Either way keep a couple filters with you and if needed the tools to change it.

[facemelter71]

Yea the fuel filters really like to cause odd problems. I never heard of them having pedal problems.

[Stangman]

You'll need a truck box in the bed soon for all these spare diesel parts you gotta haul around! :lol:

[thecollector]

Have to get it on a scanner and watch pid inputs to pinpoint. Mechanical fuel pressure gauge and check boost and tp inputs.

If I was a gambling man without a shop full of test equipment id throw a pedal on it. Lots of 7.3s around of that age you could swap a known good one during a test drive and see- don't take the salesman with you.

[jk5.0]

If it was a TP or APP problem the computer should go into safe mode meaning that the computer would only allow minimal power to keep it from a running away. This should be indicated by a check engine light an a low power light to come on and will not go away till the key is cycled again. I would definitely put a code scanner on it to see what codes it has thrown

[Steves LX]

If it was a TP or APP problem the computer should go into safe mode meaning that the computer would only allow minimal power to keep it from a running away. This should be indicated by a check engine light an a low power light to come on and will not go away till the key is cycled again. I would definitely put a code scanner on it to see what codes it has thrown

Ive had my own scanner on it plus three others and it has no codes.

[Steves LX]

It did some more stupid stuff to me last night. I almost got T boned by a semi crossing over 32. I took off and the truck went to idle and it wouldn't go nowhere. Until I threw it in park and shut it off. Thats the first time its done that.

[jk5.0]

That sucks that there is no code. Electrical gremlins are the worst with no indication on where to look. Do you know any one that has a F250 that would let you try out there pedal assembly? I would hate to see you buy one just to find out that’s not the problem I am sure its not cheap. Good luck man hope you figure it out.

[Steves LX]

Well I went and waisted more money today on a pedal. And that did absolutely nothing. I checked my fuel filter and its as clean as it was 5000 miles ago when I put it in. I give up now. Ready to burn this POS to the ground. I should've bought a chevy or a dodge.:mad::mad::mad::mad:

[Steves LX]

Everyday it gets worse. Couldn't drive it today if I wanted to. It wont stay running. It will now start up and the wait to start light keeps cycling on. and after about 10 seconds or so the truck shuts off. If I leave the key turned to key on engine off you can hear the glow plug relay clicking every 10 seconds or so. This is the first and last diesel I will ever own. As soon as I figure out how to fix it ir pay someone to fix it. Its up for sale.

[ponymom05]

Don't give up yet. Call Travis Dykes, he's an expert on diesels. Tell him Cathy Storn gave you his number. He won't know me as Tom. 859-991-8337

[thecollector]

Well I went and waisted more money today on a pedal. And that did absolutely nothing. I checked my fuel filter and its as clean as it was 5000 miles ago when I put it in. I give up now. Ready to burn this POS to the ground. I should've bought a chevy or a dodge.:mad::mad::mad::mad:

Let's not throw out the baby with the bathwater now. Can your scanner stream live data or is it just a code reader? Can it run koeo or koer tests? No modern vehicle can be diagnosed over the phone or internet, without the right tools its a guessing game regardless of brand or engine type. Its probably less than a half hour diagnosis. Call me if you want to limp it over to mason. 398-7795.