DS4 to DB2 Swap

[Robyn]

I know this subject has been thrashed some but I will ask.
I am rebuilding My 94 6.5 and the question of putting a DB2 pump back on instead of the electronic one came up.
I know there is a publication on how to do it on a 2WD with auto and a stick shift.
I have a 94 with auto tranny and 4X4 and really want to do this conversion.
I have heard many stories and varying accounts of success.
Any good info on this would be GREAT

Robyn

[More Power]

Depends on your transfer case. Interface issues haven't been completely resolved when converting a vehicle with auto 4WD. If you have a manual transfer case, the info is available. :)

Jim

[Bnave95]

I know this subject has been thrashed some but I will ask.
I am rebuilding My 94 6.5 and the question of putting a DB2 pump back on instead of the electronic one came up.
I know there is a publication on how to do it on a 2WD with auto and a stick shift.
I have a 94 with auto tranny and 4X4 and really want to do this conversion.
I have heard many stories and varying accounts of success.
Any good info on this would be GREAT

Robyn
Many times I read where someone wan't to change out the DS-4 pump to mech. My 2c is why? Having the Diesel Page with me the DS-4 has been a very good pump. I'll also read where other members what to install the DS-4 pump for the elect. can change fuel rate,control boost for different altitude. This change out makes alot of sence;)

[Robyn]

Thanks for the replies folks
I have learned of a local fellow who has done it and went to talk with him and just got back.
I tried out his truck and was not impressed with the way the tranny shifts.
I have ordered all the new wiring for the engine to eliminate any problems with the elctronics between the pump and the computer.
I have had no problem with the pump or any drivability problems other than the PMD and I have a SOL D on it.
Cold start issues in winter below 30 but I can fix that. I believe now that the best way is to leave the thing stock except for a remote mounted PMD.
I am going to have the pump run up and tested while the engine is out and I am working on it.
Again thanks for the input.
Robyn

[BobND]

GOOD plan, (I think).

I have a 1994 that I bought YEARS ago with 54,000 miles on it. The pump HAD been changed before I got it, and I had PMD trouble ONCE. I remote-mounted it and have had NO more fuel injection system problems, and it's now at 194,000 miles.

Some folks sure seem to have problems, though!

[Bobbie Martin]

Many times I read where someone wan't to change out the DS-4 pump to mech. My 2c is why?
They wanted a truck they could rely on!

[Bobbie Martin]

Thanks for the replies folks
I have learned of a local fellow who has done it and went to talk with him and just got back.
I tried out his truck and was not impressed with the way the tranny shifts.


This is the classic example of a poorly done conversion. If you have an automatic and want the transmission to shift properly, you really need a standalone trans computer. On some 4X4's is not a big problem, others it is. 2WDs are easy! If you ever get to Jacksonville, I'll let you drive a DB2 equipped 6.5 that shifts great.

[BobND]

They wanted a truck they could rely on!

I don't consider my 1994 unreliable for one IP problem (PMD), in 136,000 miles, going from 54,000, when I bought it, to 190,000 now!

I wonder why some folks have had so many problems???

[Bobbie Martin]

I would submit that its not "some" folks that have had problems, its most. My experience is very few had the reliability you enjoy. I also wonder how many problems your truck had before you bought it. GM didn't extend the warranty because there wasn't a problem. I'm sure it was to prevent a class action lawsuit and the negative publicity that would have accompanied it. Drop by any Stanadyne dealer and ask them about DS4's.

However, don't take my word, just look at any online dealer that sells 6.5 parts and read what they say about DS4's. Here is a quick sample from some Diesel Page advertisers talking about the DS4 pump: "The failure that most 6.5 owners experience..", "Long a source of problems", "The FSD cannot withstand the excessive heat and fails" and "The PMD is prone to failure". And here is a quote from our own Jim Bigley "The Stanadyne DS4 electronic fuel injection pump began as a marvelous concept in fuel injection, but it has produced enough problems to warrant finding a way to improve reliability." I think you get the idea. These 6.5 experts all have the same view of the DS4 that I do - its unreliable. They just have a different opinion about how to correct it. However, it is interesting that one of the more popular DS4 PMD relocation heat sinks previously advertised that there were no reported failures when using their device. They no longer state that, but sell an "improved" model. I will say their fix is easier but I think mine will give more long term reliability.

[Robyn]

Well I bought my first 6.5 in 93 and it was great. It was a club cab pickup.
This little creature ran like a scalded dog. (DB2 in 93) but I needed more room for people.
I traded this truck for a 94 dually crew cab with the "New electronic injection"
Gawd what a mistake, my 93 would tow circles around it. same gears, tranny ect.
Nothing but grief after about 20K miles. Stalls, hard starting, and all the other usual DS4 failures.
I traded this truck in for a Dodge with a V10 WOW what an animal would do everything I asked of it, mileage was as would be expected. Could not keep a tranny in it. Traded this POS for a 97 1 ton power stroke (another bad plan, enough said)
Finally out of desperation and the need for a truck that would be reliable I sold the stroke and bought an 86 GMC dually 4X4 with a 454 in it and a zilllllllllllllllllllllllllllllllllllllion miles on it. Geez the old Jimmy has only let me down once in almost 6 years and that was for a plugged fuel filter under the truck that one of the previous owners had stuck in a secluded spot and That I did not know about. Fixed that issue and other than normal stuff like tune ups and lube and the little stuff like a leaky water pump that had gawd knows how many miles on it this truck has been a blessing.
I have redone the interior to a much custom look and spruced the old girl up a tad now.
Built a long stroke 503 for it 2 years ago to give it some real zip. Overall this old Jimmy is alway ready to go to work and do its job.
No other truck since my 93 club cab ever completed a vacation horse trip pulling the 6 place gooseneck. All the others untill the 86 Jimmy folded up along the trail some place and had to be either towed in or fixed to get them home.
I know this sounds like a real sob story but its all about Detroit garbage from
companies that have secumbed to government pressure to produce cleaner exhaust and have done so the CHEEEEEEEEEEEEEEEEEap way at the buyers expense.
Of all the rigs I have owned over the years this approx 4 year span of trucks I owned was the absolute worst nightmare.
Now back to the present.
With the onset of high fuel prices the need for 2 large vehicles that would be economical to drive became a real issue.
We also had a 95 Suburban 6.5 that had enough pump issues to drive you to drink. Traded it for another 95 with a 454 in it and put 250K on it until one day my other half was driving it to our office and a tie rod broke causing her to lose control. The poor little truck swapped ends twice and landed on its side in the ditch. (ALL BENT UP)
No one was injured thankfully.
Now back to the need for fuel economy.
Sold the 95 Sub on ebay for a few bucks and a happy new owner flew in from the Midwest and fixed it up enough to drive it home and that was that.
Enter 2 94 Subs with 6.5's
Bought one locally and the other off ebay from central California.
After becoming quite well aquainted with this fine Place (The diesel page) I decided that the issues with the 6.5 could be dealt with.
We were off and running. Both our new found little Subs were working fine untill about 3 months after we got them, THEN IT HAPPENED my other halfs Sub died abruptly one morning about 2 am AAAAAAAAAAAACK oh well a trip to the diesel page and an aftermarket driver box and it was pretty well ok except during real cold weather. 15-20 F (Western Oregon)
The other Sub is still running like a champ.
Last week my spouses Sub took the big poop and either lost a head gasket or
something as it started blowing white smoke that smells like antifreeze, HMMMMMMMMMMMMMMM well it had a gallon of green in the crankcase when I drained it.
I will know more in a few day after I get it apart.
over 200k on it now ( we put 40k on it since we bought it off ebay)

If this sounds like a bad luck truck story well I dont know, you decide.
My main interest in the DB2 swap is this. The engine is going to be out and easy to work on and going back in clean and fresh, why not consider fixing a problem that will never fully go away. All the issues with the DS4 simply go into remission for a time and then come back to haunt sooner or later.
I have the time now to explore many options and pick and choose.
The truck is paid for and cost me 8k to buy it and its in nice shape, why not make it a great truck and fix some of the issues.
I have even thought about trying to find a 91 Sub with a 6.2 and a 400 Turbo but I am soooooooooo tired of truck projects.
The sad thing is that this scenario will play out again and again with other hapless souls that dont have tha ability I do to get out the tools and wrench on the beasties.
I have two neighbors that have Duramax trucks that are giving them fits.
The BS never gets any better, Detroit dumps one bad design and moves on to another fiasco. Never do we truely see a real good product offered for sale any more.
For all the money spent and heartache I could have gone to freightliner and had a custom hauler with a Cat engine and a Fuller tranny and been done with it and still be enjoying a good truck.

Hangs head in sorrow
Robyn

[BobND]

I have to agree with you on the problems with newer trucks, in general.

I know a couple of guys with Duramax's who are always taking them into the shop for one little problem after another, and another guy who always seems to be trading some problem away. I know 2 guys with 6.0 Fords, one of whom claims he's never have any problems, and the other guy who is looking to replace his "shop queen".

What does this mean for some of us who can't afford a new truck? Do we even DARE to buy a used newer unit? What are major out-of-warrantee problems going to cost with any of the "big three" diesels?

Going back to the DB-2 vs. DS-4 question, I have vehicles with both.

The DS-4, as long as it's working, is under computer feedback control of injection timing, and that seems to work accurately for a long service life, helping mileage.

IMHO, the DB-2, while not nearly as likely to "go down", leaving you stranded does seem to have a habit of wearing over time, and no longer giving the desired advance curve, leading to poorer economy.

I don't know what a fair mileage number would be to put on a DB-2 before it starts needing a tune-up, but I have seen many that have been run far beyond the point they SHOULD have been rebuilt, with scored advance pistons and worn housing bores that were abviously way off from the desired advance curve..

So, my point is, I agree the DB-2 is less likely to leave you stranded, but a DB-2 needs $$$$ now and then, too, to keep it operating to "spec"for top efficiency.

[Robyn]

I finally got the engine out of the Sub late this afternoon.
GAWD what nightmare to get to all the bolts on the bell housing. The clown who thought that running the fuel lines up the back of the engine between the engine and the firewall should have been drawn and quartered, then fed to the guppies.
Took me most of the morning only after lowering the back of the transfer case down to the cross member to free up some room to get the 6 bolts out of the tranny.
ell you what there is going to be some things moved when it goes back together. One is the fuel filter and the other is the fuel lines.
Going to mount the filter over by the washer bottle and the lines are coming up that side of the firewall too. I think the return line can remain but I am going to trash all the tweeky little bell housing bolts with the towers on them except two. The two lower ones need to stay as does the second on up on the passenger side to fasten goodies too.
I am going to rework that bogus heater hose with the kewl little quicky plug that leaks too. A piece of copper tube with a bend and some ferrels soldered on to keep the hose can work to skirt around the turbo doen pipe and some stock heater hose and a barb fitting to hook into the crossover pipe.
The issue is "The more they overthink the plumbing the easier it is to stop up the drain"
It used to take me no more than 2-3 hours to get a 6.2 out of an early Blazer, pickup or Sub.
This witch was about 8 hours of pure missery without breaking stuff.
What ever happened to well designed rigs?????
My kingdom for a 91 Diesel Sub.Well all for now and we shall see what is inside the beastie soon enough

Robyn