DS4 IP rebuild time(mechanical aspect only)

[Acesneights1]

I wish I had a junk DS4 to dissect.

 

[bison]

I wish I had a junk DS4 to dissect.

Want one? I got a whole pile to choose from:smile5:

 

[schiker]

The IP came from a guy over on the Page. It was having some timing issues and fishbiting. He tried several things to fix the biting from fuel supply to grounds and ended up changing the IP which finally cured it. I had posted back and forth with him on the thread and he offered the pump for postage so I jumped on it to look at one on the insides. I was looking for anything that would indicate problems metering fuel and the metering solenoid plunger also had some discolorizations similar in appearance. I did not really get into the AP until 6.2Turbo and you peaked my interest in finding out how it works exactly.

I agree could have been water, bio, or other fuel quality issue that discolored it and wore it. I don't think it had that many miles and the truck was reported to run fine with a new IP.

 

[schiker]

Just thinking about it again it seems most of the wear discolorization on my particular AP is on the side with the 3 drilled cross holes that I noted would be sealed off by the bore wall. They would also help lube the AP too.

Bison I agree with some points you made. Water would tend to settle downward and the AP bore does not get a very good flushing of fuel to clean it out. The AP probably does but not its bore path At least not as good as the plungers, rollers, and cam areas that get a good bath while running. Plus as Diesel fuel warms it looses lubricity. Would the bottom of the IP get that much hotter being close to the valley of the engine? And or frequent warm shut downs restart cycles plus with out a good flushing flow aggrivate issues.....maybe ??? If IP was starved for fuel I am guessing the AP bore might suffer the most as constant RPM changes would push pull the AP and without excess fuel it might want to almost hydrolock and suck/blow some fuel back and forth through these passages from the AP bore reusing the some of the same Diesel fuel over and over (more than intended by design?). In which case any reusing of fuel instead of flushing would aggrivate lubricity issues????

IIRC the fuel metering solenoid plunger also doesn't have a real good flushing either and this IP had some similar discolorizations.

Poor lift pumps seems to kill the Cummins IP's outright. Might be our pumps it is just a much slower death from poor fuel supply but comparable.

Bison of the pumps you have been into do you see any trends for wear?

I keep thinking about that plastic ring in the transfer pump that holds the vanes or "walls" out so they won't fall out of their slots depending on rotation stop. And wonder just how good of positive displacement pump this rotary vane pump design is???? Would appreciable excess LP pressure distort this plastic ring detrimentally ? And how much it might "slip" if starved for fuel?

 

[bk95td]

Here's the stepper motor test from the 95 gm manual. Your ohm reading were within spec and from the right pins. Sorry about the crappy scan.

 

[davo727]

Nice!

Have any of you guys tracked down a source of new parts at decent prices for these? Im wondering what it would cost for a new rotor head and whatever would be needed to do a really premium quality pump rebuild.

 

[bison]

Just thinking about it again it seems most of the wear discolorization on my particular AP is on the side with the 3 drilled cross holes that I noted would be sealed off by the bore wall. They would also help lube the AP too.

Bison I agree with some points you made. Water would tend to settle downward and the AP bore does not get a very good flushing of fuel to clean it out. The AP probably does but not its bore path At least not as good as the plungers, rollers, and cam areas that get a good bath while running. Plus as Diesel fuel warms it looses lubricity. Would the bottom of the IP get that much hotter being close to the valley of the engine? And or frequent warm shut downs restart cycles plus with out a good flushing flow aggrivate issues.....maybe ??? If IP was starved for fuel I am guessing the AP bore might suffer the most as constant RPM changes would push pull the AP and without excess fuel it might want to almost hydrolock and suck/blow some fuel back and forth through these passages from the AP bore reusing the some of the same Diesel fuel over and over (more than intended by design?). In which case any reusing of fuel instead of flushing would aggrivate lubricity issues????

IIRC the fuel metering solenoid plunger also doesn't have a real good flushing either and this IP had some similar discolorizations.

Poor lift pumps seems to kill the Cummins IP's outright. Might be our pumps it is just a much slower death from poor fuel supply but comparable.

Bison of the pumps you have been into do you see any trends for wear?

I keep thinking about that plastic ring in the transfer pump that holds the vanes or "walls" out so they won't fall out of their slots depending on rotation stop. And wonder just how good of positive displacement pump this rotary vane pump design is???? Would appreciable excess LP pressure distort this plastic ring detrimentally ? And how much it might "slip" if starved for fuel?

I have only taken one pump apart and from another only the advance piston yet. The AP from the first was spotless,the sec was scuffed at the bottom,not just discolored.I have to look into more pumps to get a more clear insight in what goes on.

I believe also ,overheating and lack of lubricity trough lack of fuel is the main cause of mech failure.

In both pumps there was some black deposits in the AP bore,so flushing of fuel there seems minimal at best if any.

The metering/spillvalve however gets plenty high presure flushing IMO.

I believe factory stock use only steel components,but reman might use some plastic parts today. The crushring in my kit was plastic,the old one was steel.

 

[bison]

Here's the stepper motor test from the 95 gm manual. Your ohm reading were within spec and from the right pins. Sorry about the crappy scan.

Thanks for the specs BK.
But it still dont tell me how to test for working.

2 diff rebuilders i contacted told me they did.nt know either how to test them off the pump.

 

[bison]

Nice!

Have any of you guys tracked down a source of new parts at decent prices for these? Im wondering what it would cost for a new rotor head and whatever would be needed to do a really premium quality pump rebuild.

New parts are expensive,most rebuilders use good used parts taken from other pumps they told me.
For example
A new stepper motor runs around $200 Cdn.
A new rotor head is around $1400 Cdn.
Prob cheaper in the US.

 

[schiker]

The metering/spillvalve however gets plenty high presure flushing IMO.

I believe factory stock use only steel components,but reman might use some plastic parts today. The crushring in my kit was plastic,the old one was steel.

Not the metering spillvalve mechanism in the "rotor?" Yeah, that should get a good flushing. I mean the solenoid "rod"?

Here are some pics of mine again this pump was having fishbiting and timing issues.

Pic 1, 2 the metering solenoid rod. Fretting is not the most appropriate word but you see the discolorization. The heavier finer scratches are from me tossing parts around probably.

Pic 3 the metering solenoid

Pic 4 my tranfer pump the white ring is a plastic of some sorts. I can't remember if this was a rebuilt or remorked pump I don't think so but could be mistaken.

Anyway I think these two mechanism suffer most with fuel quality/supply issues: the advance piston and the fuel metering solenoid rod.

This is the only pump I have been into so I don't have a good idea of normal wear or colors etc. Its hard to capture the surface quality in pics too. I have some metrology knowledge of fine finishes of Ra down to 4, some 4-16 and up to 125 mico inches but this is super finishing/ polishing a little beyond me.

 

[bison]

I dont know if that bit of wear on the FS plunger has a whole lot of impact on the working,it moves only 5 thou,altough it does it a zillion times an hr.

 

[schiker]

Good point but looking at the "bruising" its much longer than 0.005" and I am suspicious that its so fast in the milli seconds range it might just make a difference in precise control and compensation thus contribute to fishbite maybe ???? This IP had some episodes with code 36 ??? related to solenoid closure I believe.

Side story....

Unrelated to the pump in pics but my truck has some issues with idle control and something that feels similar to clutch chatter that I can corelate pretty good to fuel quality. The truck runs ok but when launching in 2nd or reverse I get clutch chatter from diesel harmonics and the electronic controls I think. It won't do it in 1st gear. When I run good fuel (fresh, lubed, and cetane boosted) it launches smoothly. If I run crappy fuel it chatters. The severity has increased with age I think due to wear issues. Several years ago my LP quit and I didn't know it for a while (I hadn't had the truck all that long was only driving easy and before my fuel pressure guage or any mods).

 

[Matt Bachand]

Any possibility having that straw feed hole machined out larger would gain anything?

 

[bison]

]Good point but looking at the "bruising" its much longer than 0.005" [/B]and I am suspicious that its so fast in the milli seconds range it might just make a difference in precise control and compensation thus contribute to fishbite maybe ???? This IP had some episodes with code 36 ??? related to solenoid closure I believe.

Side story....

Unrelated to the pump in pics but my truck has some issues with idle control and something that feels similar to clutch chatter that I can corelate pretty good to fuel quality. The truck runs ok but when launching in 2nd or reverse I get clutch chatter from diesel harmonics and the electronic controls I think. It won't do it in 1st gear. When I run good fuel (fresh, lubed, and cetane boosted) it launches smoothly. If I run crappy fuel it chatters. The severity has increased with age I think due to wear issues. Several years ago my LP quit and I didn't know it for a while (I hadn't had the truck all that long was only driving easy and before my fuel pressure guage or any mods).

The pin is running in a bushing me thinks,so the wear/contact area is much larger than the stroke.But you got a point with that millisecond operation.

Stanadyne could tell ye all about it if they just would have the decency to make info avalable :mad2:

If that pump you got apart is in good shape,plunk it together and try it on your truck,I got all the hard parts you might need.:thumbsup:

 

[bison]

Any possibility having that straw feed hole machined out larger would gain anything?

try it and let us know:smile5:

 

[schiker]

6.2turbo mentioned he JB weld plugs some holes in DB pumps and increases plunger sizes so things can be done.

Flow is tricky sometimes more than it appears. It takes the path of least resistance and if you increase flow one place it might rob from another. I don't know all the ramifications. Maybe chamfering some holes and porting and blending might provide some throttle response benefits after feeding the beast mod???

I am thinking maybe a bigger/better return check valve with better precision pressure control and some type of monitoring of housing pressure might reveal some areas for marginal benefits but without changing the plungers and cam components the injection really won't change you'll just be increasing some effeciencies and reliability (typical 6.5 gains no real magazine power gains). If you can optimize Diesel fuel temperature you might see a few HP but not many.

 

[schiker]

Bison thanks for the offer but this pump has been apart unprotected too long. I was a little rough taking it apart breaking some things and many of the little "shims", spring seats, and pieces have a little rust on them and several little pieces are missing. I wouldn't want to do all the work with such little confidence in the pump especially in my only truck. If I had another truck to experiment some with that would be interesting to see how it goes and watch some things.

 

[bison]

Well,i found out that the stepper motor runs on AC volt.
I used a toy electric train controller that happens to have a12 v AC outlet:smile5:

 

[NVW]

Well,i found out that the stepper motor runs on AC volt.
I used a toy electric train controller that happens to have a12 v AC outlet:smile5:

Just happened to have one kicking around? Took time off from play?

 

[bison]

Leo,I should've charged you an extra $50 for that info:mad2: