Question for thepumpguysc or anyone that has any insight on a Delphi pump?

[twr]

This one may be long so please hang with me, I have a Ford/New Holland 555E backhoe, with a 450 New Holland engine, with a Delphi DP203 emissionized injection pump. Came in with crank and start but would not throttle up, cable moved but no response, so I pulled the pump and sent it off for a rebuild. Got pump back timed the engine according to the service manual, 28 degrees BTDC, with marks on the flywheel, and verified by pulling the valve cover and checking No 1. Assembled rest of fuel system, bleed by loosening injector lines and cranked, got fuel, tightened lines and started. Machine started and ran like it should, had remove a leaking cylinder for repacking, so I moved machine, and all of the sudden the throttle response got worse and worse, and then when you got it throttled up and let off the pedal it would idle down and die, long crank and sometimes would restart, other times would have to let electric pump run before it would try to start. Eventually wouldn't restart, made sure we had fuel coming to injection pump verified by clear hose, would not get any fuel out of injector lines. Checked voltage to fuel shut off, even pulled and made sure it was working, even went as far as to remove the plunger and reinstall and still no fuel from injector lines. Decided to pull pump and send back, they wouldn't really say what was wrong with it, other than rambling on. Got pump back, installed like I had done before, almost same spill, bleed system, start and run with good throttle response, killed and restart throttle lagged worse and worse to the point where it would kill it self at any reduction of the throttle. Checked fuel tank for water or debris, was clean, checked sediment bowl, blew air through all fuel lines, no trash at all in the lines. Decided to try and run a new 12v lift pump out of a clean bucket straight to the injection pump. Only thing we hadn't checked was the return line, removed the line from tee and installed clear hose to the bucket, not a drop of fuel out of the return line, removed line from pump and found part of a plastic plug stuck in the bottom of the hole. Installed line and had some fuel coming from return, still no change, also no fuel out of injector lines again. Removed pump and sent back to the shop, this time they say nothing is wrong? What am I missing here, the same failure happened twice, any insight would be much appreciated!

 

[joe--h]

Shudda sent it to thepumpguy first time.

Joe H

 

[thepumpguysc]

Hmmm..when you ran it into (return) and out of (inlet) a bucket did u have your spare supply pump hooked up.?
Did u take the return fitting completely off of the pump for inspection.??
They have a tendency to rust the ball in it..
Did the shop actually TELL YOU what was wrong with it the first time.?? The original symptoms sounded like water/rust on the components..??
Your symptoms now sound like either fuel supply OR the drive hub keeps slipping.??
Are u sending the drive hub WITH THE PUMP when you send it out.?? OR is it nutted directly to the gear.??
Either case, the hub, shaft and nut MUST BE DEGREASED BEFORE installation.. I use blue loctite on my threads and torque the nut to 130 ftlbs..
Run thru your timing again and see if u can tell if the hub slipped..

 

[twr]

Thanks for replying. After we took the pump back to p ump shop for the second time, they still could see nothing wrong so he just replaced it with another pump but the first pump did not have hardly any return fuel and we put the second pump on it had a lot of return fuel and it ran fine. Still don't know what was going on.

 

[thepumpguysc]

Ur still having trouble or the new pump fixed it.??
I’m gonna go out on a limb and say return connector (non-return valve)
Hell, I’ve seen them get stuck on the test stand and blow the front seals out.!!
U wanna talk about a mess.!!
There’s a spec on the test plan where u actually take a housing pressure reading.. @ “x” rpm..
Some people do and some people don’t.. it depends on the type of test stand they’re using.
If it’s fixed, great..
I gotta say, either you’re a good customer or they didn’t have much faith in the tech who built the pump.. it’s “uncommon” to hand out ANOTHER PUMP..

 

[twr]

No sir it fixed it and I've been doing stuff with them for almost 40 years several pumps a year

 

[thepumpguysc]

Good for u.. I kinda figured it was 1 or the other..

 

[Welder Dave]

It's refreshing when a shop stands behind their work instead of coming up with all kinds of excuses and/or blaming the customer.