Uneven Idle/Lope

[Case500D]

Hi Guys,



Last night my truck started to lope at 25 t0 30 mph. It ws worse in 3rd gear, but would also do it in second. It just did it when you went down a hill or let of the accelerator. As soon as you sped up or put it under a load, it would smooth out. Also, the idle speed seemed to flucuate. It just kept going up and down. It would only do that in neutral or park. In gear with the brakes on, it was perfectly smooth. To me it seemed like the pump govenors couldn't figure out what speed to stay at. Is my injection pump dying? The truck starts, runs, and shuts off fine. THere is no abnormal smoke. I did get a tank full of fuel yesterday, but I have always gotten good fuel from the Co-op. I did drain the fuel filter off, but noticed no difference inthe loping at an idle or at 30 mph. Any help is greatly appreciated!



Thanks,



Jeremy

 

[Grey Wolf]

Case,



I think you hit the nail on the head, the govenor is "Hunting". How many miles do you have on the engine?

 

[Case500D]

Mileage

Grey Wolf,



The truck has 186,000 miles on it. It looks like the pump has been off at least once because it has no paint on it. I think was under a safety recall, but am not sure. Is there any way to diagnose the pump on the truck? Also, is there much of a price difference between the stock pump and a 230 hp pump? How about internal differences? Thanks.



Jeremy

 

[Grey Wolf]

Case,



I pulled my pump at about 248,000 and had it rebuilt, it had just about worn through the breakover spring but it was still working fine. It was something to watch around home, However I was about to take a trip to Oregon and didn't want any problems on the road, so I pulled it and had a shop go through it. During my discussions with the shop they informed me that I had "Gotten my moneys worth out of the pump" so I felt good about that.



Anyway to get to point I would look through this link and pick a shop near you and go down and talk to them. If you would like to go to the higher horse pump then tell them what you would like and they'll set it up for you. In my case I had the 180 Hp injectors and I just asked them to set up the pump accordingly.



The shops on the link are linked together and support each other as far as the pump repairs are concerned and if you wander through the site you notice some of the people and shops on this board are members. I've used them for about twenty plus years and have nothing but good luck with them.



As far as prices go it depends on what needs to be replaced in the pump, they can be as low as $500 and can go up to $800or more. Like I said you need to take a run down and discuss your options.



Hope this helps!





http://www.diesel.org/mem_serv/memdir.cfm

 

[Case500D]

Thanks

Thanks Grey Wolf,



I appreciate the help. I wonder how long I can keep running the truck. My ideal future setup includes a 230 hp pump, so maybe now is the time to go for it.



Does anyone know if I can have my stock pump rebuilt for 230 hp without killing the longevity of the pump? I am going to have to do some fast research as I need the truck. That or the pump will have to keep going for a while. It does sound kind of cool with it loping. Sounds like a big Cummins with an inline pump. Dang, the wife is going to shoot me and my truck. The brakes and now this. Oh well, it is cheaper and better than a new truck.





Jeremy

 

[Case500D]

Thanks

Thanks Grey Wolf,



I appreciate the help. I wonder how long I can keep running the truck. My ideal future setup includes a 230 hp pump, so maybe now is the time to go for it.



Does anyone know if I can have my stock pump rebuilt for 230 hp without killing the longevity of the pump? I am going to have to do some fast research as I need the truck. That or the pump will have to keep going for a while. It does sound kind of cool with it loping. Sounds like a big Cummins with an inline pump. Dang, the wife is going to shoot me and my truck. The brakes and now this. Oh well, it is cheaper and better than a new truck.





Jeremy

 

[BushWakr - RIP]

Jeremy, it's kinda suspicious that this coincided with a fill up.

Don't be too quick to discount marginal/poor fuel as a culprit.





Bob.

 

[Case500D]

I am planning on running another tank of fuel through the truck along with a can of fuel conditioner. I have had the throttle stick a couple of times also. After a WOT start, it sticks at 40 mph. If you just tap the accelerator it falls off. I have checked the linkages and have found no problems. I will do more looking and researching tomorrow.



Jeremy

 

[Wayno]

About eight months ago I went into a auto parts store and left my truck running. When I came back out it sounded like someone had put a HP cam in it. It was lopping bad and I thought oh no there goes the injector pump. I had only been putting ten dollars of fuel in it here and there,had not fill the fuel tank up in a while and had not put any fuel conditioner in it in a while either. So I went back inside the parts store and got a bottle of Stanadyne Performance Formula fuel conditioner(a 16 oz. bottle)and dump the whole bottle in the tank(with not much fuel in the tank). I ran the truck down the road a few miles and then went home and let it idle and it idle fine. So the moral of this story is I put Fuel conditioner in ever tank of fuel now. --------- Dump a bottle of Stanadyne in it or some of that Chevron injector cleaner(in that blue bottle,if you are not useing it already) and see what happens.

 

[Dfeland]

Jeremy I had the exact same thing happen but it turned out to be water in the fuel. I shut the truck off and the drained the seperator and it has run perfect ever since(20,000mi). Just a thought.

 

[Grey Wolf]

Case,



The guys have some good points here, check them out before you get serious with the pump... . doctoring the fuel is definitely cheaper that rebuilding the pump, especially if it does the job!



One of the other things that wears is the throttle shaft, I'm not sure if that could cause the sticking you speak of, but if it wears enough you'll know pretty quick. The O ring will not seat in the bore and you'll develop a nice fuel leak, then you need pump help!



My 2 cents

 

[Case500D]

Hi Guys,



I am glad to hear that someone else has had the same problem. I put in 25 gallons of fuel. The water in fuel light never came on, but I went ahead and drained the fuel filter off anyway. I know the sensor works as it is almost new and the light cycles everytime the truck is started. I have ran the Standodyne fuel conditioner, but never saw any thing special with it. I hope it will pull me out of this though. Any thoughts on why bad fuel would make it lope or act like the govenros are hunting? I willlet you guys know what happens. I was wondering if it was my pump more so I wouldn't get stranded away from home. But I will run it till it dies. Just hope that is a couple of years from now Although the 230 hp pump looks very interesting . . . Oo.



Thanks again for the help and ideas!



Jeremy

 

[BushWakr - RIP]

Ohhhh surrrre,, nozzles AND a 230 pump eh... ... .

If I didn't know better, I'd say your trying to have a hay hauler that matches wild man, nascar mark...

Next thing you know, we'll be hearing about the valve spring replacement, drugs, and ladder bars... . who said farmboys can't compete...

 

[Case500D]

Problem fixed, I think

Bob,



You are right, eventually I will get 300 RWH out of the old Dodge. It will be a sleeper too. Just wait till I smoke a new Duramax or PS and have 15,000 lbs in tow Okay, at least it is fun to think about.



Anyway, a new fuel filter and a can of Standodyne fuel conditioner seemed to have fixed the loping and uneven idle problems. I talked to Les at Scheid Diesel here in Lafayette and he said if the pump was dying, I would have very hard starting problems. I hope this fixes everything. Thanks for the help guys!



Jeremy