I just bought a 95' F-250 7.3 auto. The engine runs great except for when it hiccups. The whole truck will start to jerk and the rpm gauge fluxuates up by a few hundred then it will stop. It does it any time at any rpm. I have had the codes read but it did not show any. Sometimes the check engine light will come on but most of the time it won't. I have changed the oil, and every filter on the truck. Air, fuel, everything. It is driving me nuts! Please help!

 

Let me know what you find out, i had this same problem, then it thru a code for the map sensor, i changed it, and all was good for a week , now
the hiccup is back...YOu might want to change the CPS too..I went
that route too but it didnt help..I'm still living with this problem

 

I am not an electrical wizard by any means. Did you think to look at the injection control module? By the sound of the description, it is shutting the fuel down and refiring. Or you may have a connection in the valve cover gasket going goofy. JUst a thought or two.

 

Have you unplugged the fuel heater? Midways down on the fuel bowl drivers side. This can cause a problem if it gets loose in the filter housing is can short out, usually kills the engine and blows a fuse under the hood, but can cause what you are describing.

John

 

John
were is this connection????
On my 97 I do not have any wires on my fuel bowl(drivers side) i do have
a rectangular box connected to it and then a wire connecting to that..
I have wires in the front of the fuel bowl down low..

Do you have a picture??

Your the second person to tell me to try this, but i cant find it
and the Ford CD is worthless for pictures

 

69crewcab pull the fuel filter out and follow the heater wire thru the housing. I thought they were the same 94-97 but that's what I get for thinking hehe.

John

 

Bilder 12- Where is the module? It doesn't do it all the time by the way, sometimes it is fine the whole day, and then sometimes it does it frequently. It also has 314,000 miles on it! Could anyone recommend a GOOD manuel for these diesel engines? Thanks for the help!

 

fordgirl
Wow i thought i had miles at 257,000
That module is bolted onto the drivers side inner fender(alot of people think its the
computer for the truck) that module is $800 new from ford

 

my truck does the same i have a 96 f350 psd , i replaced the cps, inj. mod, inj. harness valve cover gaskets fuel filters thermostat because it seems to do it more when cold, hope somebody has a fix for this problem that so many of hasmy truck has 321,987 miles on it

 

So ken your truck still does it too???

Did you try the unhooking of your fuel heater?

 

Camshaft position senser. You can get them from International at about 3/5th the price that Ford charges. Your engine is an International T444E. Ask for a CMP sensor for your year of engine.

 

My brothers truck (175,000, 95 .psd .auto) does something similar to this only when engine is cold. I wouldnt really call it a hiccup, more like a pulsating of the engine or erratic type running condition. It only does this with minimal load on it and straightens out when you accelerate, and runs perfectly after engine reaches normal operating temperature. Is this what you guys are describing? If not has anyone else ever experienced this? The PCM and the CMP have been replaced for other problems as well as fuel filter and mechancial low pressure pump. Will be testing and replacing all injectors soon, just wondering if we are headed in the right direction as the injectors are original. Thanks-Ryan

 

My '99.5 did a rolling miss at idle that would come and go. It turned out to be bad injector wiring harness's inside of the valve cover.
Pictures and story: https://www.ford-trucks.com/forums/s...d.php?t=278697

 

Thanks Kwik. Appreciate the help. This truck burnt up a wiring harness last year in the pass. side valve cover so its new and the problem never got better or worse. Will be replacing glowplugs when we do the injectors so I'll definitely be sure to check out the other side. By the way the truck is not actually missing, its hard to explain. Its almost like he is feathering the throttle only really fast, faster than the human foot can move. I know what a miss is like and this is different. With a strait pipe I can really hear what the engine is doing throught the exhaust. Since this truck only does it when its cold (which is at least 5min every time he drives it) I would think we would get a DTC for a missfire or something, actually I am hoping for one, but after 3 years of this I dont guess we'll be that lucky. Thanks for your help!
Ryan

 

Hmmm, how about the throttle position sensor? These rigs are drive by wire and a bad signal from the TPS will make the engine do funny things. From what I hear it's a commone replacement item at Ford.