Ok folks,


The time has come to do something about my current pickle. This is the deal. I have a 94 ECM programmed for a 5068 series DS-4 pump. Only problem there is that I recently lost the optical sensor and then the fuel solenoid most likely. The 5068 might be 10,000 miles or 80,000 miles old on a rebuild (green tag). I don't know which because although I paid $2500 for an R&R on the pump, I question whether or not I got screwed by my mechanic on that one.


So, currently I'm running a 5288 generously donated along with a pyro guage by gmctd, and thanks again for that. It was hard to start and I had to advance the timing very advanced just to start it. Throws a code 036 every startup, TDG says cam ring is different in these two pumps and 36 might go with a new ECM.


My choices so far:


1. Buy an ECM from a 95, Is that a OBDI 95, or OBDII? i would think OBDI


2. Explore the possabilities of upgrading to an OBDII ECM how much rewiring and easiest way to get the memory flashed.


3. Put a new fuel solenoid and optical/thermister on 5068 pump and reinstall with current ECM.


What would you do? money matters it spend fast.Edited by: quantum mechanic

Finally got my dialup to hook! I would check the encoder wheel which I guess is what the gear heads (Meant nicely) call a cam ring and see if the spacing(Actual size of slot)and count of the slots is the same.(512 and 8) I can't imagine that they would change this but if so you could maybe use your old encoder wheel (Proper electronic terminology) You had the ECM programmed for a 5086 series pump? I'm curious as to what the differences are. It would be weird for GM to change the encoder but maybe they did for higher resolution? If so then the early ones would have had 256,128 or any derivitive of 8. If I'm correct they should have 512. Maybe TDG or gmctd could verify if there is different encoders and to what the differences are. I know I would like to know as it would affect my other current project a external mount (Thru oil fill maybe?) high-resolution magnetic (Or optical) encoder.

Now that my brain just kicked in I realize that a Cam Ring maybe a different internal part in the IP. I remember someone refering to the optic sensor wheel as a "cam ring" and thought that was what you were refering to. (Which you maybe, I have not tore a IP apart yet! And do not know the diesel lingo!) If so maybe this could be changed? It would be a lot easier than changing your ECM. My 95 is OBDII.


I found this link. http://www.realdiesel.com/ds4pump.html What part are you refering to as the cam ring?


P.S. Got your PM. I'll check that post here soon.

Is the ECM actually different or is it just the chip? If it is the ECM, is the chip different too?


I heard somewhere that the ECM is the same on a gasser and the only difference is the chip. If this is true, you could get one from almost any salvage yard.

Get the '95 OBD-I PCM, or at least the prom from one - it would have all the production fixes in it as '96 went to OBD-II across the land.


Think it will cure your problems.


OBD-II has same signals, but all PCM connectors are totally scrambled from OBD-I.


I've had a notion to re-wire and try it, but the hot re-flashes are around 600 bucks.


The '99 is the hottest oem flash, but don't even compare to the 80mm3 in my hot prom upgrade and the hot flashes.

I found a prom for a '95 6.5 but the place said they couldn't verify if it was auto tranny OBDI or if it even worked! $115 with a core, noway I'm handing over the only chip I know about to run the 5068 pump. The way I see it the're no good without each other.Edited by: quantum mechanic

Just the chip shouldn't be that much from a dealer.


I think I heard somewhere that it was around $40


You can get a performance chip from Heath Diesel for $299 or from Kennedy for $350 (you might as well since you probably get one eventually anywayhttp://www.dieselplace.com/forum/smileys/HiHi.gif)


You should be able to call either of them to find out what will work.

"93 has no prom at all, that won't work. I'll call the dealer but at $40 that doesn't sound like the dealer prices I'm used to. Worst case I'll put it on a card and if it doesn't work I'll complain to the credit company and demand a charge back. I can't spend $300 on a chip right this second, but If someone happens to have one....

OK got a price from the dealer $70. not bad, but they can't tell me what chip is the right one without a number for the prom or a 95 OBDI vin #.


Can anyone help me with this?

OK got a price from the dealer $70. not bad, but they can't tell me what chip is the right one without a number for the prom or a 95 OBDI vin #.


Can anyone help me with this?





http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2487049057&catego ry=13487


1GCGC24FXSZ210250 (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewJumpPageForVehicleHistory&vin=1G CGC24FXSZ210250)


chevy


http://motors.search-desc.ebay.com/diesel_Passenger-Vehicles_W0QQfromZR7QQsacategoryZ6001QQsamotorscat egorymapZ6001QQsamotorsendyearZ1995QQsamotorsmakeZ chevroletQQsamotorsstartyearZ1995QQsas_partneridZ2 QQsotextsearchedZ2


GMC


http://motors.search-desc.ebay.com/diesel_Passenger-Vehicles_W0QQfromZR7QQsacategoryZ6001QQsamotorscat egorymapZ6001QQsamotorsendyearZ1995QQsamotorsmakeZ gmcQQsamotorsstartyearZ1995QQsas_partneridZ2QQsote xtsearchedZ2


http://www.dieselplace.com/forum/smileys/Cool.gif

Thanks for the links.


I have found that GM has little knowledge of how to upgrade from my BJAX coded BPBN 1621 7103 serial #chip(pn#1624-4854) by referencing the TSB on prom upgrades. possibly too much water under the bridge. I must have been passed from parts to service and back again 5 times.

http://xtronics.com/memory/how_EPROM-works.htm


This is general information about eproms and thier programming.


gmctd, I can verify AOD but not OBDI or OBDII. If I get the wrong ECM I think I will try to rewire it, or at least the connector. I'm going to ask them to identyfy the prom. I looked at mine and it's a blueplastic shell and chip. TThe flash is different with a sticker on it(uv window) and bigger.Edited by: quantum mechanic

If you see the blue plastic prom carrier it is OBD-I.


Clear window is to erase the e-prom with u-v, so it can be reprogrammed.


Plain black chip is prom - one-time programmable, throw it away if ECO dictates firmware changes.

Problem solved. put a 95 "F" engine AOD ECM with blue prom.


This wasn't that easy, yeah The first one I tried worked but trying to index the prom upgrade was like pulling teeth. Not GM or anyone who rebuilds stanadyne pumps, not TDG or even Bill Heath could say for sure which prom I had to have to run a 5288 pump.


Is there really no idex available for this? I think in ten years guys will have a harder time trying to do something like this as all the early trucks dissapear. The c2500 L65 this ECM came off of was already scrapped.


I started with a 16183977 series ECM {BJAX} with prom ID {BPBN 1621 7103} GM part#1624-4854. This ran my 5068 DS-4 pump in my k3500.


The upgrade is a 16212488 series ECM with prom ID {BPAA 1621 6871}. This runs the 5288-54?? series DS-4 pumps.


I didn't have to buy an ECM but I got to thinking how the pump and the ECM were a pair and togather you could run a 6.5 in anything. One of the trucks I have that doesn't drive is a '72 k/5 blazer.Hmmm, what would it be like with a 6.5L under the hood? I would need an engine and 4L80E but I've got a pump and ECM for it.


I plugged it in and drove home, it works like it should. $155 USD


Thanks for the help. I feel like I have to know this truck to own it and the lessons never cease.


This place will rewire and reprogram your ECM


www.fulllogic.com/Pages/electronic-control-module.html (http://www.fulllogic.com/Pages/electronic-control-module.html)





Edited by: quantum mechanic