Need help with idle on Perkins 704-30 diesel engine.

Bibbyman · March 27, 2010, 06:33:08 PM

Late last fall I started noting that the Terex didn't want to drop back to slow idle. I could "blip" the accelerator a couple of times and it would fall back to slow idle. Then it got to where it wouldn't again. I oiled the cable and linkage everywhere I could find to oil it but that didn't help. I finally installed a stronger spring. That helped just a little for awhile. Then it got to where it wouldn't fall back to slow idle ever – unless I'd get out and raise the hood and give the lever a little nudge. Didn't take much but it wasn't going back to slow idle on its own.

The yesterday I was using it and it wouldn't come down from running speed let alone to fast idle. This morning I worked on it again. I added the original spring above the new, stronger spring. Now it will go back to fast idle again and take just a nudge to go back to slow idle.

I've taken the cable linkage off and feel like it's something inside the, I'm guessing, the governor that's keeping it from falling back to slow idle. It fills "ginchy" and not smooth in operation.

There is what looks to be a drain plug just below and right of the larger spring. Then there looks to be some kind of vent or fill above the linkage lever. This device is made of brass and below it on the housing is a yellow caution icon and a picture of the manual pages. I look in my almost worthless operator's manual and it makes no mention of this brass fitting/cap.

I suspect this Perkins engine is used in a number of applications.

Anyone got any clues for me to try?

SPIKER · March 28, 2010, 12:02:15 PM

I'm not sure about the perkins but on many injector pumps use independent oil that needs regular oil change or the symptoms like you describe will happen as the injector oil coaks up around the governor slider bar. (sorry if some of the terms are wrong)

You might want to dig into the manuals if you have them and check for fill & drain points on the injector pump body. Most will use 100 weight compressor oil or often 30 weight synthetic motor oil. My tractor will use just about anything but It requires changed regularly due to diesel fuel contamination which lowers the lubricating quality and the pump will start to stick some when it gets too diluted.

Mark

Bibbyman · March 28, 2010, 12:21:15 PM

Thanks,

That's what I was suspecting but I can't find anything telling about maintaining it in the manual. I'll look again.

Anyone else got directions to drain, replace the oil? What oil to use?

Update:

Mary found the Perkins engine manual I never remembered we had. It tells all the obvious maintenance activities and step by step how to perform them. But when it comes to the injector pump and regulator, it has a picture of it with a hand holding a screwdriver with a BIG X placed over it. To shorten the short paragraph, it says don't mess with it – take it to authorized Terex service center.

It makes no mention of the oil to use or when it is to be replaced or where the fill port is. (I see the drain port.)

LAZERDAN · March 28, 2010, 02:56:50 PM

Hey you could call Hucksdorf diesel. ( just for advise) all they do is diesel and thats it. That have been nothing but helpful for me. here's the link http://www.hdiesel.com/ Lazerdan

Bibbyman · March 28, 2010, 04:14:44 PM

I've got a couple of resources I could call. I just hate to bug them on Sunday. We could even wait until tomorrow and call the local heavy equipment mechanic. We've spent a lot of money with them but they've been awful good about handing out "fix it yourself" info.

I just figured with so many guys on the Forum with mills and equipment with similar diesel engines there would be someone that would be able to put me on the right path. (I think I'm on the right path, just now there are a couple of forks in the road up ahead.)

isawlogs · March 28, 2010, 07:33:52 PM

How many hours on that pump .. you could be looking at a rebuild . Have put any oil in your fuel to help lub the pump ??6 , With todays fuel it helps to add lub.
Have that issue dealt with , you may start that engin and have it rev up and not being able to shut down before it shuts on its own ,... then it gets a little late :-\

Bibbyman · March 28, 2010, 10:37:42 PM

I don't think it's the injector pump that's causing the problem. I think it's what ever inside that housing in front of the pump with the linkage that controls the pump. It looks like it runs in it's own oil bath.

pineywoods · March 30, 2010, 10:34:11 PM

Bibby, I think you will find that's the governor, most likely the cause of your problem.

Bibbyman · March 31, 2010, 02:11:38 AM

Quote from: pineywoods on March 30, 2010, 10:34:11 PM
Bibby, I think you will find that's the governor, most likely the cause of your problem.

Is that something I can fix or do I have to call in an expert?

I guess I probably answered my own question if I have to ask.

Bibbyman · March 31, 2010, 09:44:12 PM

Well, that fixed it... :'(

I guess the two springs was too much for the cable or foot-feed linkage. This afternoon I was all but done using it when the foot-feed went to the floor and the idle dropped back to slow. So slow it wouldn't move. What to do? It was setting in the middle of our road. I thought a minute about how I was going to pull it back out of the road when I came on an idea of getting a piece of electric fence wire and wiring the throttle linkage to about 1/3 throttle. That worked. I was able to creep the Terex back into the shed and out of the way.

Tomorrow I guess I'll have to take out the kick pannels and see if the end pulled off the cable or maybe the foot-feed linkage broke. The cable is fine where it hooks to the engine.

If it ain't one thing, it's another! First the broken off key. No ... first it was the ruptured tilt cylinder, then it was the broken off key and then the F/R shifter and now this!

Bibbyman · April 01, 2010, 12:31:24 PM

I got the cable out with a good bit of head scratching, skinned knuckles, taking off shielding to get to shielding to take off to get to things I needed to get to.

But I did discover a problem – maybe THE problem. The cable goes through the floor in the cab of the Terex and down though a gooseneck pipe. It then turns up between the frame and a belly pan. The belly pan was pushed up a couple of inches and had mashed the cable between it and the frame.

What a design! Put on all kinds of shielding and then leave about 2" of the cable exposed under the cab in the most vulnerable spot where the belly pan can crush in on it.

Got a new cable on order. No such thing as a free lunch. This one will equal the best steak dinner for four and a good bottle of wine. I guess it's the Windy's dollar menu for me.

bill m · April 01, 2010, 12:50:33 PM

Quote from: Bibbyman on March 31, 2010, 09:44:12 PM
Well, that fixed it... :'(

If it ain't one thing, it's another! First the broken off key. No ... first it was the ruptured tilt cylinder, then it was the broken off key and then the F/R shifter and now this!

Isn't owning equipment great :D :D :D