Is there any way to tell from the VIN, or other means to tell which IP is installed in a K2500? The orignial IP was replaced at 110K under warranty. I think I may be looking at another.:(

Use an inspection mirror - read the Stanadyne label on the rear of the IP - DS4-XXXX

Or, check the paper tag, usually at the rear, also - gives date and model.

Anyway to tell from the codes/numbers on the chip in the PCM?

Do a search, here, for 5068, 5068 eprom, and such - several posts listed the numbers.

Bet bet is to look at the tag on the IP.

Anyway to tell from the codes/numbers on the chip in the PCM?
What is your 4 letter chip code? I've got a chart that tells me a general breakdown, but the best way is like gmctd said.

OEM chip has BXRJ code.

As I recall, when I was at Kennedy's and bought/installed his chip, he had to cross-ref the OEM chip 'cause we couldn't get in close enough or make out the tag on the IP.

You can usually see the tag pretty easily w/o a mirror if you just remove the upper intake plenum, that will let you know what you have.

OEM chip has BXRJ code.
BXRJ is for a 94 3500 auto with a 5521 compatible pump, BXRF BPBN BMSD BPBM BLRL BJAX and BKWJ are the ones I have listed for the 5068 series pump.

Thanks Fermanator. Looks like I'll be ordering a pump. Did the 'poor cold water over the pump' thing earlier when the truck didn't want to start. Waited a minute, it fired up.

Hold up there ... are you SURE it's the IP? The cold-water thing really only works on bad PMDs. I know you have yours remote-mounted, but it can still take a dive... I had one do that, and once I replaced it, everything was fine.

If your PMD is still mounted in side the engine compartment, you have more than enough temperature in there to 'heat-soak' the thing when you shut off the motor and it will still die eventually (although it will last a lot longer once you get it out from under the intake). Best idea is to get it right outta the engine compartment, on a big enough heat sink to dissipate the operating heat.

You may well be right, and you need an IP, but it's a lot of money blown if you end up being wrong ... if you aren't throwing any codes, it's more likely the PMD. Just my 2bits.

My PMD is remote and on a heat sink in front of the radiator. Has been for quite a while and was new when it was placed there. I'm all for replacing the PMD if that's it, but I believe I have crossed that bridge. Used a known good PMD (my get home PMD from the glove box) and the problem persists. I can even swap the PMDs during the 'heat soak' condition and it has no effect.

Hold up there ... are you SURE it's the IP? The cold-water thing really only works on bad PMDs.

Not so.

BXRJ is for a 94 3500 auto with a 5521 compatible pump, BXRF BPBN BMSD BPBM BLRL BJAX and BKWJ are the ones I have listed for the 5068 series pump.


Can you tell which pump I most likely have using my prom code? BXRS...

Can you tell which pump I most likely have using my prom code? BXRS...
All 94 1500's used the 5521 style pump, but the BXRS is a 94 1500 PROM 3.42 or 3.73 gears with an auto.

Correct - the 5068 was the HO Inj Pump for the F series engine - Stanadyne tried it for a couple years, only, found they could get better results with programming.

Thanks!

Not so.

So which is it - the cool water test? Indicate bad IP or PMD? IP is ~$1k; PMD is ~$300. $700 buys a few tanks of diesel.

I believe the cold water trick changes the clearances inside the IP....thus if it starts with water poured on it I would assume the IP is worn out.....

5068 was only used on 94 heavy duty models. Think u will also find that if it has an egr it takes a 5521. No egr = 5068

If the truck has had the ecm updated it will take the 5521

I guess I could be wrong (not like it hasn't happened before :-)

I was told that the cold water test worked on the PMD, and it did, when mine died... I would have thought that just splashing cold water on the IP wouldn't be enough to change clearances... metal has a pretty high heat coefficient, and the inside of the pump wouldn't cool off very fast if the surface was splashed, to my thinking.

Now, if you kept doing it over and over, then I could see it working on the IP, too.

But I'll take your word on it, if you think the IP responds to a cold splash. I'd hate to hand out bad gossip.

AND - the reason I have a Heath PMD Isolator is because I've HAD a remote PMD fail. Seven year warranty is a lot more convincing when you've had a remote PMD crap out because somebody said the heat sink under the hood was good enough and their warranty ends at 366 days, so sorry, thanks for coming out.

However, you've tested it with a known good PMD, so I was wrong again. Never hurts to test out the cheaper part first!

According to my papers and my research, the 5068 was only used on trucks badged HD on the door tag(3500HD or 2500 HD). These were the ones with the different grill in them I believe. I may be wrong(has happened MANY times before), but this is what I've found.

Hey Fermanator ... what have you got on your cross-reference for a BKWJ ??
( a little presumptuous of me to ask, but... please?)

Hey Fermanator ... what have you got on your cross-reference for a BKWJ ??
( a little presumptuous of me to ask, but... please?)


BXRJ is for a 94 3500 auto with a 5521 compatible pump, BXRF BPBN BMSD BPBM BLRL BJAX and BKWJ are the ones I have listed for the 5068 series pump.
BKWJ is listed in my guide as a 94 3500HD with the 5068 pump

Sigh... it happened again. I read it, but I didn't get it. Sorry for asking about things that have already been answered.

The 3500HD trucks had a solid I-beam front axle with leaf springs, much stronger frame, and 10-bolt 19" wheels - the frame rear section with rear suspension\axle could be shortened or extended by removing the frame bolts and sliding the section in or out

It was designed to take the small Cat 6cyl Diesel engine - back when GM and Caterpillar were talking to each other about such things - and which required the body be raised about 5".

Thus - the wierd extension under the standard grille\fenders.

The Cat deal never came to fruition - probably because GM did not have a compatible automatic transmission - but the revised heavy duty truck was good for a low-profile - hence the name Lo-Pro - ton-and-a-half truck, which could be licensed as a 3500HD to avoid the commercial penalties.

The 454 and 6.5LTD engines were standard, usually with the NV4500, tho I did see one with a 350 between the rails.

And, that's the rest of the story................

BXRJ is for a 94 3500 auto with a 5521 compatible pump, BXRF BPBN BMSD BPBM BLRL BJAX and BKWJ are the ones I have listed for the 5068 series pump.
Fermanator,

Would BXRJ then be a suitable replacement for my BMSD since I'm swapping in a used 5521 for my original 5068? The engine has no EGR and the 4l80E auto.

I'm rebuilding a 6.5TD to drop into my '93 K2500 Suburban (currently with 454 @376k miles) using a '94 c3500 donor truck for the harnesses, computer, radiator, etc. I'm having the heads done with 6.2 style pre-cups (single dot) for maximum fuel economy. I know I could probably get a performance chip that would be compatible with the 5521 and no EGR, but I'm hoping I can find the right stock chip to start with as I suspect it'll offer better fuel economy, plus, they're generally $70 vs. $300.

When GM replaced the IPs on these HD trucks, didn't they replace the 5068s with the newer 5521 (and/or compatible) pumps and replace the PROMs? I'm hoping there is a table somwhere showing the correct PROM update for each application of the newer pump.

Thanks in advance.

The "cold water trick" was mainly for the DB2 mechanical pumps. Rare to have same issue with a DS4 electronic pump, but possible just the same...