450C fuel strainer on I.P.?

[JWedd]

Hi all, this forum has been very helpful! Appreciate any help I can get.

I'm having start up and running issues. It acts like a fuel flow problem. I replaced the fuel filter (was very dirty), and for good measure, the transfer/lift pump. Blew the line from the fuel pump inlet to the tank. Have good flow at the injector pump inlet. Engine starts reluctantly, runs relatively smoothly but does not respond quickly to any throttle lever changes. Fuel tank cap is removed, tank is full. Drain sump cleaned.

This is a 4239T engine that the previous owner dropped in to replace the 4219T.

I am leaning towards looking for a strainer below the IP inlet. Would this Lucas pump likely have one? The Roosa-Master diagram 1D11 looks very much like my IP.

I also disconnected the return line at the tank and at the IP. I blew it out, and reconnected. Fuel flows slowly out this line when running. I did not check for flow out of individual injectors. I blew into the fitting at the tank, but could not tell if it was plugged.

I'd post photos, but I do not have a host.

John/Fresno

[LeonardL]

I don't know if the Lucas pump has a strainer at the IP like the Roosa Master / Stanadyne's do or not. I would make sure you are getting plenty of flow to the IP and then try bleeding the injector lines at the injectors. I'm assuming you bled the air out of the filter when you changed it? It sounds like air to me but you could also have a bad pump. Or at least in need of an overhaul.

[LeonardL]

I did a little poking around and found a Lucas pump parts break down and it shows a small nylon filter under the fuel inlet. I just Googled "Lucas Injection Pump Parts Diagram" and found this link. Maybe this will help. (https://www.stationaryengineparts.com/l ... s-diagram/ )

[Jim B]

After reading LeonardL's reply, a thought occurred to me. Is this a new issue or has it been ongoing? If it has been this way since you got it there is the chance the injection pump is not right for the application. If this engine came from a stationary application, the pump adjustments and governor may not be right for using in your crawler. A pump shop may be able to tell from the numbers on the pump.

[JWedd]

Thanks for the replies!

This is a new issue. I haven't tried to bleed at the injectors yet (as you know, it is a PITA trying to get the two wrenches at once. Since it runs, I thought it would push the air out on its own).

Since then, I believe I have ID'd a check valve on the return line, looks just like the infamous check valves on the 219's. I will try to remove it and see if that is plugged with carbon fiber gear particles. Maybe temporarily get it going.

There is a strainer on this pump inlet. But a lot of little parts that need to be pulled out. After watching You Tube videos, it looks like the whole outside end should be pulled out in order to reassemble properly.

First : check valve check
Second: individual injector bleeding
Third: strainer, (or maybe I call in a mechanic at that point)

[Jim B]

If it runs, an injector with air should clear itself after a couple minutes of runtime, without bleeding.

[JWedd]

I have almost always had it clear air, once it begins to catch.

I did not run out of fuel, so I do not think the issue is air. I changed the fuel filter, blew out the low pressure lines, reprimed, all good. When it started the low power issue, it had been a few months since last running.

It could be in the air intake, or the turbo gone down. I'm not getting any black smoke that would suggest a rich condition. High vacuum sensor not popped. It behaves like a fuel starvation problem.

But first that return line check valve on the IP needs to be removed and inspected.

[JWedd]

ok here's the update. I resorted to calling the dealer repairman. He's always been quick and knowledgeable, and willing to share. We traded several texts about what to do/check in case the problem could be solved without a repair cost from him. He did not have anything different to say other than what I'd already checked. I thought that the strainer in the IP was plugged. He came with the idea that he might have to get into the IP, possibly removing it for rebuild.

Firstly, he could not get the new fuel lift pump that I had installed to work smoothly (I had bought an aftermarket pump). So he replaced that with a John Deere part. Then, he said the internals of the injection pump were "gummed up". I'm not sure how he cleaned this up. He recommended adding fuel conditioner to the fuel.

Now, everything running great! Starts instantly, lots of power, like new! Happy man here. I've never used fuel conditioner, several decades of tractor use etc, never any problem. I've heard that ATF was a good idea (apparently, 40 years ago) but not recommended anymore. Anyone have a name of a product?