Perkins running rough

[Welder Dave]

I didn't think a 4-154 was ever put in a tractor.

 

[wlhequipment]

Might not be exactly a 4.154, but something real close to it. I dunno, we’ll have to see

 

[wlhequipment]

Turn the low idle down to 700-800rpm and button it up and send it down the road..

I was hoping I had it ironed out, but I don’t. Cylinder 1 is still colder than the others, white smoke upon start up, and low power and black smoke while under even a light load. Aside from some mysterious thing that I can’t measure going on in the cylinders, my problem has to be the pump. It seems like I can get one for 500-1500 bucks, but I would need to know the p/n of mine, so I’d know what to order. Since I don’t have a data plate, that’s pretty hard to do. I could call my local Perkins dealer and get the Perkins number, but other than that, is there another way to identify exactly what pump I have?

 

[Vetech63]

Cylinder 1 is still colder than the others, white smoke upon start up, and low power and black smoke while under even a light load

What is the temp difference?

my problem has to be the pump

Maybe.........have you swapped the injectors to see if the problem moves? Have you checked the engine compression on ALL the cylinders?

 

[wlhequipment]

What is the temp difference?

Maybe.........have you swapped the injectors to see if the problem moves? Have you checked the engine compression on ALL the cylinders?

Temp difference is over 100 degrees. Cylinders 2-4 are in the 400 range and 1 is in 300. I’ve moved injectors.

 

[thepumpguysc]

Well there ya go..
If cyl 1 is only at 300 psi.. there’s your white smoking problem..
U could try adjusting the valves but other than that.. ur looking at rings.
How many times have you hit it w ether.??
R u talking compression or temp.??

 

[wlhequipment]

Well there ya go..
If cyl 1 is only at 300 psi.. there’s your white smoking problem..
U could try adjusting the valves but other than that.. ur looking at rings.
How many times have you hit it w ether.??

OOPS those were temperatures not compressions The compressions are all in the 360 range. The temp I'm reading with a laser thermometer right on the exhaust port. The temps go up the longer I run it, but the difference stays significant no matter what I do. Cyl 1 is always much lower exhaust temp. Never used ether on a diesel.

 

[Vetech63]

OOPS those were temperatures not compressions The compressions are all in the 360 range. The temp I'm reading with a laser thermometer right on the exhaust port. The temps go up the longer I run it, but the difference stays significant no matter what I do. Cyl 1 is always much lower exhaust temp. Never used ether on a diesel.

Something isnt making sense. You have good compression all the way across, the problem didn't move when you swapped injectors. All it takes to fire is good compression and the right amount of atomized fuel at the right time. Its sounding like the injector pump isn't pushing enough fuel to #1 injector or that injector isn't atomizing the fuel (which would be unlikely since the problem didn't move during the swap)

 

[wlhequipment]

Something isnt making sense. You have good compression all the way across, the problem didn't move when you swapped injectors. All it takes to fire is good compression and the right amount of atomized fuel at the right time. Its sounding like the injector pump isn't pushing enough fuel to #1 injector or that injector isn't atomizing the fuel (which would be unlikely since the problem didn't move during the swap)

Right! That’s the core of the matter. The problem with that is, it’s a rotary pump. I have a vague understanding of how they work, and a single cylinder failure seems almost impossible. By that, I mean, if cyl 1 had failed because if a worn out cam, then cyl 4 (or whichever one, I can’t remember firing order) would also fail, because it uses the same cam lobes. How can a rotary pump fail on just one cylinder? That’s my conundrum. This one really has me.

 

[Vetech63]

Put a dial indicator on your valves above the pushrods and measure the travel through a cycle by hand. Im wondering if you have a cam lobe or lifter going down and its effecting the air flow

 

[Tinkerer]

Is there any chance that something is restricting the fuel flow in the injector line ?
Just a thought, disconnect the lines on #1 and #2 injectors and get an accurate measurement of the fuel coming through them for comparison.

 

[wlhequipment]

Put a dial indicator on your valves above the pushrods and measure the travel through a cycle by hand. Im wondering if you have a cam lobe or lifter going down and its effecting the air flow

Definitely worth a look, but I think this type of thing is covered by a compression check. I give it 10 cranks through compression for each cylinder, and take my measurement there. If it takes one cylinder longer to get to 350 or whatever, that’s the one with valve problems. That’s a good idea though, I’ll give it a go possibly tomorrow. Thanks!

 

[wlhequipment]

Is there any chance that something is restricting the fuel flow in the injector line ?
Just a thought, disconnect the lines on #1 and #2 injectors and get an accurate measurement of the fuel coming through them for comparison.

I’ve never heard of this. Aside from the line being damaged / bent / kinked, I don’t know what could be in there that would survive those pressures. I can’t really rule anything out yet though.

 

[Tinkerer]

I had an experience with a minute piece of metal lodged in a line once. It took me a while to find it.
I changed out the pump for a new one and the problem persisted. That's when a I smelled a rat so to speak.

 

[wlhequipment]

Get this - funny little ending to this story. First of all, I tried all the recent suggestions from everyone, I especially liked the dial gauge on the tappet. Very clever on that one! In any case, still no trouble found. Engine still runs a bit rough. The only thing left to do is send the pump out for bench check / overhaul, which could take weeks, and may not even yield any fruit. Not alot of shops even willing to work on this old pump, but there are a few. Anyway, so I had "that" conversation with the guy. You know the one where I say I can't figure out what's wrong, and we need more expertise than I can provide, and this old stuff is hard to find support for etc etc... The kind of phone calls I HATE. I mean, seriously, my stomach was in knots about this. I've been a mechanic for 30 years, and I can count on one hand the number of times I've come up with nothing. Well, maybe I need one more finger now. Anyway, so I call the guy and take him through all this, and he says not to worry, other mechanics have been telling him this for years, and he'll take it the way it is, no sweat. Years? YEARS? and he couldn't maybe have shared this with me before I spent freaking forever trying to figure this old POS out? YEARS? UGH. well its over. Thank you all for your help with this. Imma take the next couple days off - hope you all can too Is it beer:30 yet?