Vibrating Injection Pump

[djr99]

We have a 1st gen truck with a vibration in 1200-1500 rpm range. The vibration is coming from the injection pump. You can see the pump vibrating and can feel it in the accelerator pedal. It also makes a pecular whining noise. Its OK at idle, and above 1800. Anyone come accross this problem before?

 

[BushWakr - RIP]

Hi djr99 ... welcome to the ranch bud... .....



When you get a chance try filling in your "signature". You do that by going into

"user cp" and following the link(s).



As for the vibrating injection pump, I haven't heard of this particular problem... however, if the pump is physically shaking/vibrating then something is not right to be sure...

I'd recommend making sure that all the pump mounting bolts are tight. There are 3 15mm nuts at the front of the pump and they attach the pump body to the gear casing. There is also a small 10mm bolt to check too... . it is at the very bottom of the pump, almost past the bottom end of the pump itself. It (the bolt) faces toward the firewall and threads into a bracket down there. If you twist yer head and look down there you'll just make out the little booger.....

If they are all tight then it sounds like you have an internal issue. I'm thinking that the only parts that could cause the problem you describe are the governor counter weights and/or the two heavy springs which keep the cam plate and roller ring in contact. These springs aren't particularly large in size but are brutally tough. If there is a problem with either of those items you are on an unpleasant course for failure... .

There is one other item to check.

Remove the engine oil filler tube by unscrewing it from it's 90* elbow on the gear case, then, un screw that mounting elbow too.....

Use a mirror and a flashlight and look inside at the pump gear/nut assembly. Does it show any sign of slop or having backed off???? If so, you GOT to fix it yesterday...



If there are any other symptoms that you can think of put them in here and the rest of the guys will jump in with ideas for you as well... .



pastor bob...

 

[Phil Stuart]

Injection Pump gear/shaft play

Pastor Bob, read your reply and you said about slop in the gear or shaft.

When I killed/tabbed the KDP last summer I was checking all the bolts inside the gear case while I had the cover off and did notice a bit of side to side or lateral play in the gear or shaft assy. I made sure the nut on the inj. pump shaft was tight and was ok. The slop didn't seem to be major and truck runs fine no missing. is this any indication of the bearing/s going south, if so what type bearings are in the pump? Does this mean a reman or new pump in my future?



Thanks Pastor Bob, Phil

 

[Greenleaf]

You checked the radial (up/down ) play in the pump's drive shaft? And there was a noticable amount?



I was thinking that same set of plunger, cam ring return spring(s).



The loose pump don't fly well with me caue I have seen one that wasn't tight even missing a hold down bolt and no vibes, but then not all pumps engines are the same.



I'd be lead to believe that if it vibrates as badly as you say, you'd be prone to have leakage at the lines among other locations.



-S

 

[JLEONARD]

Is it possible that the vibration is from an injector or delivery valve going south, or some other fuel delivery situation (other than main pump internals) that would manifest itself as a vibration at the pump?



Or perhaps we need to change the batteries in our pumps so we get the benefit of the vibration too :-laf oooppps... wrong forum



Jay

 

[djr99]

Vibrating Injection Pum

Yes it was the bottom bolt that was loose. Very hard to get to I might add. Your help is much appreciated. The pump had been replaced not too long ago so the bolt must not have been tightened then.

 

[Greenleaf]

I found this same thing on a pump I messed up, er... ... ... ... . I mean messed with for a fellow member. I had to loosen ALL the brace mounting cap screws to align that one hole then install the bolt. I hate it when someone does a half butt-head job of reinstalling pieces parts.



His wasn't vibrating like Jays does though.



GL

 

[BushWakr - RIP]

Scott, you are one SICK puppy... . BTW, which forum should I go to, to read about that other stuff..... :-laf :-laf



pb...

 

[BushWakr - RIP]

I can't say for certain but I don't think the DV's would be the problem here... In fact, I think you'd see other more pronouced problems if it were the DV's..... hmmmmm... ...

There should be NO play in the pump shaft as far as I understand it/experienced... none.

I'm starting to lean more toward the camplate/roller ring springs as a possible source of your problem.

Let me ask some questions at the shop and see if I get any other ideas for you.

In the mean time, I'd drive it a bit easy till we know what you're looking at for sure.



pb...

 

[JLEONARD]

Scott... . that must be why I really love to drive my truck!!! LOL

 

[Phil Stuart]

There should be NO play in the pump shaft as far as I understand it/experienced... none.

I'm starting to lean more toward the camplate/roller ring springs as a possible source of your problem.

Let me ask some questions at the shop and see if I get any other ideas for you.

In the mean time, I'd drive it a bit easy till we know what you're looking at for sure.



pb...

Pastor, The pump itself is tight on the gearcase, no looseness here but just in the pump shaft and I didn't see any signs of a leaking front pump seal either. No front to rear play, just sise to side and up/down.



Phil