****edit****
Below is my original post of my problem, the solution was the IPR valve . I changed it out and it immediately began to work fine (complete new IPR). Big thanks to all who helped and especially to those who made me aware that the engine was surging, not sputtering.

Now onto my other issue...another thread....



Hello All,


2000 7.3 F250

When i start eccelerating the engine sputters at around 1500-2000 rpms. It will also do it on the freeway. I still have good power and when i give it gas the sputtering stops. The Idle is very rough most of the time (when the sputtering is at its worst), yet about 10% of the time the idle will be normal (and sputtering will be less of a problem).

I Ohm'd the glowplugs & injectors , they are good.

I'm kinda stuck on this one and hoping i can find the problem before i have to spend $$$ on a tow. The problem is slowly getting worse (over the last 3 months).


Your help is appreciated, thanks!




‪Sputtering truck video‬‏ - YouTube

 

My gut says a fuel pressure or fuel delivery issue. Can you get a gauge onto the pressure test ports? Also, have you replaced the fuel filter lately?

http://www.swampsdiesel.com/content/faq/fuelpress.pdf

 

Thanks for the reply,

I changed the filter about 2 years ago, roughly 16k miles ago. I have no idea if i'm overdue for filter change or not . I will take a look at it though.

It will take some time for me to get a gauge and check the pressure but that sounds like the next step in trouble shooting this problem. Thanks again.

 

When you say you Ohm'd out the injectors and glow plugs...How did you do this?

Reason I ask is that it could be a loose connection at the UVCH. Ohming them out from outside the valve cover, the engine isn't running. The vibration of the engine running could be causing a slightly loose connection to fail giving you the rough running feeling.
I would remove the valve covers and check that the harness is completely plugged in solid, and that all connections at the injectors are solid.

 

Time to look at injection pressure data. Sounds like your truck is not "dropping" cylinders, but actually surging.

 

what should should he be looking for?

 

Gremlins.


All kidding aside, it sounds like his injection pressure under certain loads is surging which leads me to believe that there MAY be an IPR issue (sticking pintle within a certain duty cycle range).

Under acceleration like he was doing in the video, the ICP should be relatively stable. If the pressure is fluctuating more than a couple hundred PSI while the anomaly is occurring, he may have an IPR issue.

OP....
DO NOT throw parts at this truck based on what I've said. There isn't a soul anywhere on the internet that knows exactly what's going on here....it's in need of actual diagnosis, not guesses by people who aren't there or shouldn't have any business doing anything other than checking the oil or filling the fuel tank.

 

An extra tid-bit,

when it starts cold, idle is smooth (sputter problem still exists, just very mild), once it warms up slightly, idle becomes rough (sputter intensifies). It will do this while siting in my driveway.

Would using autoenginuity likely zero me in on the problem?


@Bill,

I thought of that too, i checked it several times after driving around, i even hit the connectors (carefully) with a broom handle while the engine was running. I have already fixed the drivers side connector a year ago. So i plan on playing the odds on that one, though i will continue to ohm test them every once in a while. If my truck dies then yay...i will have some codes to read

@Cleatus,


It doesnt feel like a surge, it may sound like one because the only way it happens is if i give it a little throttle, then i have to give it more throttle for it to stop hicup'ing. Actually, its similair to my old hotrod's throttle cam on my holley carb, the cam was too small, not enough gas in the venturi to get the car off the line. The only difference is it starts happening after i've started going, and even on the freeway.

This prob is starting to sound complicated, i'm starting to wish it would break down and spit out some codes

 

The doing it when hot seems more like an IPR issue as well, AE is a great tool, and will allow you to perform buzz and contribution tests which might point you in a direction. Maybe someone local can help, or you could pay a shop to perform the tests? The fact that you are not getting codes(Or are you not able to read them ie has the SES light come on) could lean towards fuel issues.

 

I'm not busting chops.....but it happens on internet forums ALL THE TIME.

Aimlessly testing things like that can lead the layperson down a very expensive path for no reason. For example, just because a certain cylinder shows up on a contribution test DOES NOT mean that the injector is bad. It COULD be, but that test IN NO WAY condemns injectors as the fault. ANYTHING that causes a cylinder to contribute to engine rotation speed more or less than another will show up on that test. Things like low compression are often the case so how would you feel to immediately assume that an injector is bad only to find that you just paid somebody $2500 to put injectors in a junk engine? As I said, it happens all the time.

It needs proper diagnosis. A code would be nice as it would point a person in A direction....very rarely do "codes" give an exact indication as to what is wrong.

The ONLY time a "buzz test" will tell you anything is when the fault is present at that time. If the condition only happens at a certain RPM and a certain load (as seems to be the case with this truck), then it's possible that running that test (since the engine has to be off to perform the test) wouldn't even show a problem with the injector wiring. Remember, the "buzz test" ONLY checks the electrical portion of the injector control system from the injector driver module to the injector solenoid. It tells you nothing about the internal mechanical operation of the injector.

Just some words of wisdom....and yes, I do have real-world experience.

 

I'm not doubting anyones real world experience especially yours, I too have experience and I responded to the question of will AE zero me in, in which I said it might point you in a direction? AE is not going to fix anything for you, it is just that another tool to use.

How does aimlessly testing lead to an expensive path? Proper diagnosis comes from testing? I guess I am at fault for assuming that someone asking specific questions looking for ideas to aid with their own troubleshooting thoughts, is going to just take the information as that, information and ideas.

How would you recommend the OP check ICP at acceleration and various RPM's without some diagnostic tools?

I understand that the only true way to test the mechanical side is to have them tested with proper equipment, but does it hurt to check the electrical side, not at all.

Also I don't think one reply in this thread told the OP to go buy parts and start throwing them at it.

 

Cleatus, bigalspsd,

I think you both are correct about the engine surging as apposed to cutting out.

I guess it surges, then drops out, then goes back to normal. I just don't feel a power surge, but thats likely because of my auto trans and the weight of my service bed full of tools.

I'm all for testing testing testing, whatever the problem is i can fix it. I'm new to diesels but i have a ton of experience gasers with (trucks, cars and boats). Actually, i replaced the IPR in my big 97 7.3 a few years ago. What can i do as far as testing it?