Possible Injection Pump Issue?

[Bo-Jangles]

1989 F-250 / 5Spd w 148k miles. When the rpms are 2k or above and I let completely off the accelerator pedal it is hard (stiff) when trying to get back on the throttle. There seems to be excessive resistance at the point of initial throttle input. This issue goes away when the rpms drop below 2k. Based off the maintenance notes of the previous owner the injection pump had been rebuilt at 125k but the truck sat for quite a while before i purchased it. Since owning I have run quite a bit of diesel kleen through it with every fillup as well as filled new fuel filter with straight diesel kleen to try and clean any gunk out that might have resulted from it sitting. Other than that the engine runs consistent through the rpm range, it's just the stiff pedal at higher rpms that seems odd. Any ideas what this could be? Time for a new injection pump? Thanks for any input.

 

[Rdnck84_03]

Spray some penetrating oil on the advance lever and all related parts. AKA the arm on the driver side of the injection pump.

James

 

[Clb]

Lube the pedal and cable also

 

[Jesus Freak]

And study the way the cable is around the spring and stuff at the end where it clips to the bracket by the IP. There could be something catching and snagging, the orange thingamajig is a possible culprit.

 

[Bo-Jangles]

Lubed and checked cable to pedal. Smooth consistent pressure as long as rpm's are below 2k rpm's. At that rpm or higher the pedal resistance increases noticeably. Once rpm's fall below 2k resistance goes back to normal. I can also feel this resistance when operating the throttle by hand at the injection pump taking the cable/pedal out of the equation. Makes shifting interesting when changing gears at these higher rpm's.

 

[IDIBRONCO]

I'd say that it's starting to sound like a IP issue.
Story for reference: at the shop I used to work at, we had a customer from Wyoming come in for a long block. He bought a lifetime warrantied pump and injectors from a Ford dealer. I was working with another guy doing engine swaps at that time. We got the engine running and were letting it warm up to set the timing. The other guy was working the throttle by hand and he said that it felt funny when he opened the throttle (most of the way, not just above 2000 RPM). He called the foreman over to have him work the throttle by hand. While the foreman was running the throttle, there was suddenly a LOUD screeching noise, the engine stopped, running and the IP moved all the way to the passenger's side in the slots (all three mounting nuts were tight at the time). cranking the engine over with the starter did nothing. We removed the IP and there was no resistance when turning the part that fits into the gear (I now know that the driveshaft had broken when the IP locked up). The customer wasn't very happy about having to buy a reman IP from us, but there was no other way for him to get home. He also promised to give the Ford dealer a real unhappy talking to after he got back.
The moral of that story is that, after all of the things that you've done, maybe it is time to think about a new IP. Also don't drive the truck too far, just in case the worst happens.

 

[Jesus Freak]

I'd say that it's starting to sound like a IP issue.
Story for reference: at the shop I used to work at, we had a customer from Wyoming come in for a long block. He bought a lifetime warrantied pump and injectors from a Ford dealer. I was working with another guy doing engine swaps at that time. We got the engine running and were letting it warm up to set the timing. The other guy was working the throttle by hand and he said that it felt funny when he opened the throttle (most of the way, not just above 2000 RPM). He called the foreman over to have him work the throttle by hand. While the foreman was running the throttle, there was suddenly a LOUD screeching noise, the engine stopped, running and the IP moved all the way to the passenger's side in the slots (all three mounting nuts were tight at the time). cranking the engine over with the starter did nothing. We removed the IP and there was no resistance when turning the part that fits into the gear (I now know that the driveshaft had broken when the IP locked up). The customer wasn't very happy about having to buy a reman IP from us, but there was no other way for him to get home. He also promised to give the Ford dealer a real unhappy talking to after he got back.
The moral of that story is that, after all of the things that you've done, maybe it is time to think about a new IP. Also don't drive the truck too far, just in case the worst happens.

In a strange way, this IS the benifit of mechanical machines as opposed to electronically controlled machines. In this instance you could point at the IP and say "THERE'S THE PROBLEM". If it were a powerstroke, you'd have to hook up the OB2-JNK and get a code and then access 10 different things that that code could possibly indicate, and THEN hope you were right as you were replacing the incredibly expensive electrical component.

 

[Rdnck84_03]

Lubed and checked cable to pedal. Smooth consistent pressure as long as rpm's are below 2k rpm's. At that rpm or higher the pedal resistance increases noticeably. Once rpm's fall below 2k resistance goes back to normal. I can also feel this resistance when operating the throttle by hand at the injection pump taking the cable/pedal out of the equation. Makes shifting interesting when changing gears at these higher rpm's.

I am still thinking something on the advance lever could be stiff. The truck I have been working on in my " personal salvage yard" thread I was having the same feeling in the throttle.

After soaking all of the moving parts on the driver side of the injection pump with penetrating oil and working the throttle through its full range a couple dozen times (with the engine off) it seems much smoother now.

I did also do an atf shock treatment of the pump and injectors at the same time so that could have also freed up some internal sticking.

James

 

[Bo-Jangles]

I'm going to try the penetrating oil on all external moving parts for sure. I know when the engine isn't running throttle operation at the pump itself feels normal and consistent. If the penetrating oil doesn't produce any improvements I'll start looking a little harder for a decent reman pump. I've been leaning towards an R&D pump and injectors (if it came down to needing a new pump) but they're out of stock at the moment. Hopefully if it's something internal it holds out until I can source a quality pump. Thanks for the input. I'll report back after the penetrating oil.

 

[The_Josh_Bear]

R&D is one of the good rebuilders. I got a CHRA from him locally. But since he's out of stock:

https://moosediesel.com/ is one of the good guys, and out of PA AFAIK.

https://russrepair.com/ is also one, I've had one IP rebuilt and a fresh set off pop-tested injectors, both of which are still working very well after 5-ish years. His pump rebuild time is quite good, and the damn things WORK. I've run out of fuel or gotten air in the lines plenty of times and the quality of this pump to purge itself and re-prime is amazing. A worn out pump makes you tear your hair out, been there, done that! I thank God for Russ and his rebuilder every time I have to purge my setup!! Plus, he's the only vendor(of these 4) still active on these forums. @typ4

https://classicdieseldesigns.com/ is another, these are the big 4 for IDI fuel systems.

 

[KansasIDI]

R&D is one of the good rebuilders. I got a CHRA from him locally. But since he's out of stock:

https://moosediesel.com/ is one of the good guys, and out of PA AFAIK.

https://russrepair.com/ is also one, I've had one IP rebuilt and a fresh set off pop-tested injectors, both of which are still working very well after 5-ish years. His pump rebuild time is quite good, and the damn things WORK. I've run out of fuel or gotten air in the lines plenty of times and the quality of this pump to purge itself and re-prime is amazing. A worn out pump makes you tear your hair out, been there, done that! I thank God for Russ and his rebuilder every time I have to purge my setup!! Plus, he's the only vendor(of these 4) still active on these forums. @typ4

https://classicdieseldesigns.com/ is another, these are the big 4 for IDI fuel systems.

Classic Diesel designs is in Texas
RussRepair is in Oregon
Moose Diesel is actually in South Carolina, I have a pump of theirs, it also primes up really good.

Injectors I have are from Russ, also very nice

 

[Old Goat]

R&D IDI Performance is in Gillette, Wyoming.

Goat

 

[Bo-Jangles]

Thanks for the references. No luck with the penetrating oil as far as making any noticeable difference with my issue. Looks like a new pump is in my future. Going to keep running it for now while trying to hold out for a R&D pump & injectors. Thanks again for the responses.

 

[Rdnck84_03]

Have you tried an atf treatment on the pump and injectors yet? Not sure if it will cure it but definitely worth a shot since it's far cheaper than an IP.

James

 

[Bo-Jangles]

Yes. Did the ATF and diesel kleen mix in the fuel filter, ran it for a couple minutes then let her soak (twice). No change. I'll keep running her for the time being. She ain't perfect but she runs. I'm waiting on a R&D pump and injectors. Going to cost a few shekels. Of course work is slow and budget tight, but that's life.