Hello, I've changed the hydraulic head on my Ford 655C injection pump, because it was starting very-very hard, and if the engine was warm, it won't start at all. The good news is that now it starts easy, but the regulation is poor. It has some hic-ups at rpm above idle, and even at idle it does not regulate well. It is like there is some kind of lag somewhere in the regulating loop. It tends to accelerate-reduce speed, maybe 1-2 times per second, so you can just hear this on the exhaust. Sorry I can't come with a better description. What could be happening here? Could it be that the governor to metering valve linkage is not adjusted properly, or the throttle spring to governor is loose, and it should be moved to the next hole? I will take off the head of the pump, but maybe if someone with experience knows what could be the cause. Any advice, please?
If you can give me the #'s off the nameplate, I can tell you what the spring set-up is.. Did you "adjust" the gov.-mv linkage?? Your pump may be "coded"..1st line on NP is the pump model..2nd is the pump serial #...and if theres a 3rd, thats your code..fuel output at a certain rpm, spring code[1-9] and then max rpm.
Thanks for the reply. The serial is 8523A040A - Lucas CAV DPS type. But, as far as I understand from the service manual, it isn't "coded". And I did use the same hole on the throttle link. I also did adjusted the linkage acording to manual, but maybe I was not too carefull when I did that. It stated 41.5mm +-0.5mm, and I set it at ~42mm. This adjustment was necessary, because being the first time I "repair" a rotary type of pump, I did dismantled all the stuff around there... According to manual, of course. Could it be that the adjustment is not proper? It seemed to me that the link was just less than 1mm shorter...
I found a picture, and it seems this is the info you were talking about (it's the fourth number on my nameplate): 61(?)L1100/1/2400
The "1" is the spring code..1st hole on the throttle shaft. [furthest away from the "pivot"]
A "DPS" is very tricky..where on earth did you find a "rebuild manual"?? I'v been to the "factory" training school[Delphi] and THEY couldnt get them to work..lol AT THE FACTORY SCHOOL!! We've perfected the proceedure..but still...the "layman" is no-match for the task.. I'll walk you thru it the best I can, tho..
I just have the Ford 455/555/655C service manual on PDF format. Maybe today or tommorrow I'll have time to take off the top of the pump and re-"adjust" the link. Will come back with the (hopefully good) results.
Did re-adjusted the gov. to mv linkage, but the problem is not there. First I shortened the link and after starting, I noticed that it would not rev up more than 2000rpm, but the hic-ups were present as before, so I adjusted it once more and it seems to rev up fine now, but it still doesn't regulate properly. If it is under load, it works fine, but with no load... I'll check again the end plate an the regulating valve as it's another part are I've dismantled and I put in a rubber sealing washer, that seemed to me to be a bit thick. That, I got from a pump repair kit, and it looked like it fits there. The old sealing was nearly destroyed.
If you replaced the head..are you sure you got the "scroll plates" in correctly? Did you move the regulating plug adjuster in the reg. sleeve OR did you dismantle it from the bottom? IF you unscrewed the plug from the top..thats your problem..
The scroll plates were not taken out, it's 99.99% sure that they are correctly installed. I'm sorry, but I'm not sure where is that regulating plug adjuster you are talking about... Is it somewhere in this picture? Or can you please provide me some more indications? On the other hand, I found that the idle spring (that little one) I placed it wrong, on the other side of the gov. arm .
The regulating adjuster is under the fuel inlet nut in the endplate..
I installed the idle spring correctly now, and replaced the sealing washer for the regulating adjuster sleeve with a thinner one, but there is no change in the behaviour. It still goes brum-brum-brum... The transfer pressure adjuster was not "adjusted". It seems to regulate better when cold and very bad as the engine gets warm. Is there any way to check if the transfer pressure is correct while running at, say 1000 rpm? I am also wondering: could in reality be an oscillation of the advance/retard mechanisms? I don't know what to do next, and I would not have the time to takle out the pump again and have it seen by an injection systems service as it may take up to 2 weeks to get it back. Thank you in advance.
The TP pressure is taken in the shut off solenoid port.. The solenoid is removed and an adaptor is screwed into its place and a 0-150psi guage is added to the adaptor. The advance mechanism works directly off of tp pressure. More speed = more tp pressure which = more advance.. I wish you were closer..I'd be able to knock that problem out for you in aday or 2.. What about, proper torque on the "endplate"? any sticking component in the transfer pump area will give a surge like symptom..What about t.p rotor torque? sticking blades?? On a Delphi/CAV rebuild, the transfer pump components are assembled to the head and torqued BEFORE the head is introduced to the main housing, and checked for freedom of movement, precisely for that exact reason. Good luck.
That's a good point, with the sticking blades. When I dismantled the inlet into the endplate, I chipped it's surface in a vice and I grinded it a bit to flatten it back. So, the blades could indeed be sticking! Probably, if I losen the screws a little, the problem should dissapear, right? Thank you for your patience!
NO!!!!! DONT DO IT!!!! THE ENDPLATE WILL **** AND SEIZE THE PUMP!!!! Replace the blades and the liner and torque the screws to 35-40inchlbs.
Too late! I did it, but nothing bad happened. Nothing good either. I loosened the screws a bit and started the engine. While running, I gently unscrewed the screws, until the transfer pump could no longer create pressure, and the engine died. Tightened the endplate again, and the tractor started just fine, but the irregularities did not change all this time. So I think we can rule out the blades sticking... As before, when cold, it would go nearly fine, but after a few minutes, it goes crazy and crazier. What about the latch valve, can it create such a mess?
The latch valve is used for starting/excess fuel and kicks out "just under" idle speed, using tp. pressure.. The only problem I've seen, w/ the latch valve is either a NO START[stuck piston] or NO SHUTDOWN[broken spring] condition.. NO SURGE.. If the problem didn't go away w/ loosening the endplate..doesn't mean the blades aren't stuck.OR for that matter just 1...remove the E.PL and inspect JUST TO BE SURE.. I'm leaning towards the gov. linkage OR a stuck blade..
Hello, again! Last week-end I took the pump off the tractor, mainly because I had a very BAD leak. and checked again if the scroll plates were fitted correctly, and they were. I was hoping that maybe they were not, and I could then solve my problem BUT, I took a look at the latch valve... It was so stuck (rusted), that I had to hammer it a bit to get it to move. I realy hope that this is the end of it, and in 2 days probably, I'll have it mounted and will let you know how it goes. I mention that the valve was stuck in a "engine running" position, as far as I can tell, but I can't imagine how could it happen. thepumpguysc, do you think that this could be the source of the poor regulation/surge?
I doubt it.. BUT.. stranger things have happened.. Did yours have the tamper proof cap and 3mm screw?? I hope you counted the turns on the screw or measured it before you removed it.. Hopefully is was the other type, with the jam screw..and no adjustment.. If the latch vale was stuck, then you have fuel contamination problems.. I suggest you take care of that first or you'll be chasing ghosts for a VERY long time.
Mine has the 3mm screw, but I know it's old posistion. Right now, I sure don't have any contamination problems, as the filters are new and everything is as tight as possible. The surge was present since the day I first ran this tractor, only they were less proeminent with the old and worn hydraulic head.
Yesterday evening, with only a head lamp as light source, and some verry muddy soil around, I mounted the injection pump on the tractor... Aaand, I can anounce you that my saga has come to an end! Even if I also didn't think the latch valve could be the root of all this, it was. Now my tractor runs like a normal one, and to me it's a good, comfortable feeling. I even managed to stop the leak, and it seemed to me that it even starts easier when cold. Last time, it required quite a lot of cranking to get it started, but now, with the pump just mounted moments ago (and primed, of course), it started right away, surprisingly fast! Thank you, everyone that tried to help me! Thepumpguy, you are a really nice person.
That's great news.. The faster starting makes sense.. the latch valve is part of the "cranking" circuit.. and if it was stuck open, then you wouldn't get the correct amount of starting fuel.. As far as the surging goes..??? that one still has me stumped.. OH WELL, like I said.. stranger things have happened.. Glad you got her fixed..
Hi thepumpguysc, I have a question on my fuel pump Ford 655C 1994 and was wondering if you could help me?
Sure thing.. fire away.. gonna need the #'s off the name plate on the side of the pump to be sure we're talking apples to apples tho..
Just got your email..
Fuel Pump expert!! I wanted to post a HUGE thank you to "THE PUMP GUY" your understanding and recommendations saved me big bucks and even more important a huge headache!!! If you have questions on fuel pumps etc I highly recommend this man!
Please help pumpguysc.. Would you please send me the instructions and part numbers to reseal the injection pump on my 70's Ford 4500. At least the information for the throttle shaft seal. It has the Lucas/CAV pump. It will not let me send you a message directly..
4LIFE>> info sent.. good luck.
8520A480 нужна инструкция по регулировке. CAV DPS Fuel Injection Pump Workshop Manual Lucas CAV Service Training моя почта [email protected] Спасибо!