DS4 Injection System Retrofit

[AltitudeDiesel]

Ok everyone, now I have read a lot about people swapping to the ealier DB pumps to gain reliablility and more power as opposed to the DS electronic pumps with PDM failures, optical sensors to go bad, etc. My question here is totally in the reverse way of thinking though. I have an 86 6.2 pickup and a 79 5.7 pickup that are my tinker toys. Both are using DB2 pumps and they provide plenty of fuel, etc for their application. My thinking though is can the DS4 system (pump, engine sensors, wiring, PCM) be retrofitted to a vehicle of this era to gain accuracy and the on the fly adjustment electronics provide.

I live in Colorado and I go from the Arkansas River valley @ 3200 ft to home at 4600, Denver and Colorado Springs @ 5-7000, College @ 3900 and sometimes venture into the mountains where I'll see as high as 12,000 ft. It's a real pain in the ass to set my fuel rate for home or college so I can impress everyone and then take off for a weekend to higher elevation and end up blowing black smoke and watching my EGT's climb. Electronics would solve this problem for me and would allow better accuracy with fuel rates(not "Give her a 1/6th of a turn and that should be about right") as well as more economy and a quieter engine.

I've got access to a few late 90's 6.5 pickups and I know quite a few guys with junkyards in the area who I doubt have much call for PCM's and wiring harnesses, I would imagine they'd part with them for not too much money. As far as I know the sensors required to make it work are a crank position sensor (could be a little tricky to retro), coolant temp, MAP, ??? what else. Theoretically then a Bi-Directional ODB2 device with some software such as Westers uses would allow me to do basically as I please.

Let me know how crazy you think I am, obviously I'm some sort of crazy playing with 5.7 so you're not going to insult me.

Thanks for the input,
Tony

[john8662]

You and I share the same interest in this project.

I would LOVE to have a DS4 pump in my truck.

Our needs are different, I'm looking for the better behaved engine with a smoother idle when hot, which the DB2 DOES NOT provide (I don't care what the stone throwers say).

The only Obvious problem that will have to be over come will be to get the transmission working. My problem is that mine are all automatic, so I have to have some kind of linkage for the transmission.

Some parts you'll need:

Wiring harness for an electronic 6.5 with a Manual tranny.
APP (foot petal and bracket)
PCM
Misc sensors and wires of course.

Engine related you'll need the 6.5 front timing cover and reluctor wheel for the crankshaft, and then the crank position sensor to make that complete.

I'd like to try this soon with an engine setup on a test stand I'm building just to get the engine to run (out of the vehicle) then tackle the tranny issues. The tranny problem can be solved by making or altering the APP petal to incorporate the throttle cable then attach to the Detent (700R4) or VRV for TH400, a lockup for the TH700 will have to be figured out too (manual switch worse case scenario).

The truck I want to modify is also an '86 6.2L, but not soon.

[AltitudeDiesel]

John,

Thanks for all the info. At least I don't feel quite so crazy anymore now that I know I'm not the only one who wants to attempt this. I totally agree with you as to the smooth idle. My friend has a 96 6.5 and even with my 6.2 timed on the money with perfect injectors I can't idle nearly as smooth or quite as his truck does.

Everyone has always told me that the more an engine has that "good diesel clatter" the worse it actually is for it. I know guys who would take a engine that was timed correctly and advance it just to get that clatter because they didn't think their truck sounded enough like a diesel. I'm thinking the same holds true with the DS vs DB debate. The DS4 provides a quieter running engine that is smoother and has less of that clatter. That means to me that it is more accurate, better timed, etc.

I guess my next plan of attack is to figure out how to get crank position sensing to work. I'd appreciate any information from anyone who knows more about the crank position sensing on the 6.5. Does it use any techniques that can be adapted from other engines and or retrofit kits because I'd like to duplicate this on my 5.7 as well where I can't just bolt on the 6.5 timing cover and parts. Additionally, does the DS4 and the early DB2 (2825) for the 5.7 use a different pump drive or is it just a bolt in place and rock and roll type of install.

I hope to pull this off over the summer since I'm pulling my 5.7 anyway to install a 700R4 behind it. The TH400 torque converter decided to give up the ghost and instead of installing the Gear Vendors I have for it I'm going to toss in a 700R4 to gain the lower 1st and 2nd. Any and all input for this project is appreciated.

[BobND]

I'm a believer in the DS-4, and have collected parts for this conversion, myself.

Good luck, and keep us posted on your progress!

Whether MY project ever gets done, is another matter!

To add the crank sensor, you need... a front cover, with a hole for the sensor... a sensor... a reluctor to slip on the crank snout, next to the timing gear... and a crankshaft damper intended for use with this setup... it's hub is shorter by the thickness of the reluctor, locating the front face of the damper in the same plaace as without the sensor, so the belt(s) remain in alignment.

[dieseldummy]

One idea I have for the crank sensor for the 5.7 where you can't change the cover is as follows: Basicly all you need is a way to provide the computer with a certain number of pulses per minute so the magnet and ect used for aftermarket tachs should be able to be adapted to be used as a crank sensor with the right wiring wizardry.

[john8662]

Wow, three of us are crazy!

Cool!

I'm gonna start asking my salvage yard guy here locally to find the harness. I've got an PCM from a 95 (but it was auto, all I need is another eprom), but I still need a harness.

Just an FYI, I think the 94-95 OBD-1 computer and harness will make the easiest swap.

J

[Bnave95]

I know quite a few guys with junkyards in the area who I doubt have much call for PCM's and wiring harnesses, I would imagine they'd part with them for not too much money.

If they would have a whole truck with blowen Eng. would they sell it cheep and rebuy it back after you got all the parts needed? Look for a wire harness that did not have the EGR. Use all of the front componets off the Eng.and the upper intake. Cooling Mods and DSG gear would be a good ideal. With the cooling mods you'll have the port for the temp sencer. You'll also need the glow controller. The under hood fuse box. The rest has be coverd.
I would also stay with a OBD I found in a 95 just for easy code check,chip upgrade. If non-turbo this would be in the van type system that would be needed. Sounds like a cool project that all of us would like to see :)

[AltitudeDiesel]

Great info guys, thanks for all the replies. I figured I'd be left out in the rain on this one with everyone thinking I was nuts. As far as driving the PCM with a crank position sensor, as I understand from dummydiesel the whole goal is to provide the engine with some sort of signal as to pulses per min or second or whatever. I'm driving a factory tach dash for the 73-80 pickups in my 5.7 truck and what I did was pull out the vacuum pump (only used for the TH400 and since I had a shift kit I just jammed the modulator at a position between WOT and idle where it had firm shifts at ~2000 RPM if in drive but was crisp if I shifted it manually) and since I'm now going 700R4 it isn't an issue anyway, who would have thought a snappy 5.7 would eat up torque converter.

Anyway, back to the point, I pulled out the vacuum pump and since it's basically all Oldsmobile BB parts I was able to drop a HEI distributor in place and plug right into the tach pickup wire on it to drive the gas tach. Works well, is accurate and I can run any tach in the world, no alternator only or diesel only tach garbage. What would be the chances the signal used to drive the tach would be nearly the same signal the PCM is looking for since I think that era of gas trucks were using just a distributor tach signal and I doubt GM wasted the money to redesign the PCM just for a CPS on a diesel. I might be totally wrong in that area and if I am I would still guess that signal could be modified with the correct electronics to provide a CPS style signal for the PCM.

Then the 6.2 is just a matter of installing 6.5 parts and I've got both projects solved. On another note, I'm planning on putting twin turbos on the 5.7 someday (College or turbos, hmmm... hard decision) so if I install a 6.5 DS4 system I should be able to just bolt on and go? I would guess that with no turbos it would just fuel like it was making no boost and still run fine, once I got the turbos on it would sense boost and fuel for boost? That's another story though, it'll be amazing if I'm able to pull this off over the summer since when you live on a ranch you're expected to do something more than play in the shop all day.

Thanks again guys
Tony

[BobND]

Be aware the ECM is looking for 4 pulses per crankshaft revolution, at precise points in the crank's rotation.

That is where the TDC offest number comes in... the difference in crankshaft degrees between where the optical sensor in the pump "sees" #1 TDC, and where the crankshaft position sensor "sees" #1 TDC.

[BobND]

P.S. ...

You do realize the 5.7 and 6.2/6.5 pump driveshafts and mounting flanges are completely different, right?

[Bnave95]

Be aware the ECM is looking for 4 pulses per crankshaft revolution, at precise points in the crank's rotation.

That is where the TDC offest number comes in... the difference in crankshaft degrees between where the optical sensor in the pump "sees" #1 TDC, and where the crankshaft position sensor "sees" #1 TDC.
I'll stand by this also. I would not try to come up with any thing different on the timing. Replace the front cover,make the set up as OEM if your wanting to do it right. Keep asking and we will set you stright.:D

[AltitudeDiesel]

Thanks for the replies everyone. You're helping me take this from an "I'm crazy" dream to "This just might be possible". I've began calling around to some friends at junkyards and I have a friend who is in charge of totaling vehicles who said he'd keep his eyes open for a wrecked 6.5 truck.

As far as the signal the ECM is looking for, I have been doing some reading on the reluctor pickup and I'm gathering it's an inductive crank angle sensor. Between my father and I we have a fairly diverse and good understand of electronics, circuit design, waveforms, and how to manipulate them to do what is needed. I'm gathering the 4 pulses per crankshaft revolution are evenly spaced based an initial position of ? degrees? If that is the case any number of things could be designed to provide a signal, piezo triggers on the injection lines similar to the Stanadyne Time Trac method, the CPS from the 6.5, modified distributor output, etc. I would appreciate someone taking a look at this info, I know it's for different applications but I'm guessing the same holds true across the 6.5 platform just with different points, etc. Maybe Dr. Lee would have some input on this as well since he has played with manipulating signals for different purposes (ESS for Tach).

http://www.picotech.com/auto/tutorials/trigger-signals.html

http://www.megasquirt.info/ms2/GM_DIS.htm

http://www.megasquirt.info/ms2/GM_7pinHEI.htm

As much as I'd love to go with the 6.5 components (I.E. Front cover, CPS, reluctor) I doubt they can be adapted to the 5.7 application. My current thinking is to design some type of trigger system to provide a compatible signal for the ECM without the CPS design of the 6.5. I know this is taking the long road to making this work and I should start with my 6.2 application before attacking the harder install but I need to have at least one running vehicle and since the 5.7 the non-running one it is where I have to start.

As to what BobND pointed out with the mounting flanges and driveshaft, I am fairly sure but I could be wrong, the 5.7 driveshaft can be swapped into a 6.2 pump. If that is the case it should be the same for the 6.5??? Otherwise, an adaptor could be machined (We have a mill and other equipment in our shop).

[JohnC]

If you're looking for a long, drawn out, controversial project, i think you've hit the nail on the head! If, on the other hand, you're looking for a solution to the problem, you may want to consider coming up with a boost controller that maintains a constant absolute pressure rather than a constant gauge pressure. Add an intercooler, and get better performance to boot, likely for less money...

[john8662]

Get your hands on a used DS4 pump and compare it to a DB2 pump and you'll see that NOTHING will interchange from pump to pump. I say this because of the consideration for the application on a 5.7 diesel. You won't be able to swap housings or guts from a DS4 electronic pump to mount to a 5.7, the method will be to make something.

A couple of problems with putting another pump on the 5.7 would include mounting problems, firing order concern, and the fact that 6.2's and 6.5's have an advance piston to adjust advance throuugh the rpm band, the DB2 on the 5.7's doesn't have that. What is the firing order for a 5.7? The 6.2 and 6.5 share 18726543.

Stick with converting a 6.2 engine to DS4, the parts are already available, it will be a matter of wiring for the most part.

Keep us posted on whether you find some 6.5 trucks wrecked sitting, I haven't turned up anything yet...

[moondoggie]

Good Day!

"...the on the fly adjustment electronics provide." What are these adjustments? I've got two of these trucks, & haven't seen ANYTHING that's adjustable.

"It's a real pain ... and end up blowing black smoke and watching my EGT's climb." Wouldn't it be easier to tune for low elevations, & pull your foot off the footfeed when she starts making black smoke at higher elevations?

"...as well as more economy and a quieter engine." I guess my 95's are quieter than my 82 was, but my 95's can't remotely get the fuel economy I got with that 82. I guess I'd just turn up the radio... ;)

I sure don't think you're crazy at all, in fact I envy the fact that you've got the time & smarts to even consider such a project. Because for me, that's all it'd ever be - I'm not smart enough & certainly don't have enough time to turn such a thing into a daily driver. To reiterate: I sure don't think you're crazy, in fact I'm jealous. :D

Blessings!

[AltitudeDiesel]

Thanks for all the info guys, I'm glad I'm not crazy, just over ambitious maybe. The firing order on the 5.7 is considerably different being 18436572, the mounting of the DS4 would be quite difficult and there is a lot of work involved in this type of a swap. I don't know if I'll get it all done but where there is a will there is a way. Any info as to the signals (voltages, waveforms, etc) that the PCM expects would be great. Other than that I'm pretty much on my own now as to making it work I would say.

moondoggie, you make some good points. As for the adjustments I'm speaking as for the PCM compensating for elevation, air and engine temp, etc. The EGT issue is true but at a point there is just too much fuel period, 3000 to 14000 ft is a huge difference but point well taken, that's what I resort to now is backing out of it to keep my EGT reasonable. Economy might not be true as a direct correlation due to the simple fact that 6.5 electronic has boost. I'm sure I'll be corrected for this generalizations from here on but for 14.7 PSI boost you add 1 ATM so at sea level you'd be feeding the engine 2x the air. Only way to make use of that air for power is more fuel. More fuel going the same speed = less economy. Even at 4-5 psi boost you'll see on the road you're using 20-30% more fuel. That's the difference between 20 mpg and 26 mpg. My 5.7 pickup makes ~25-30 and I've seen as high as 35 driving across flat ass Kansas, with the 700R4 swap and better rear gears I should pick up some more MPG but if not I'd say 25+ is all you can ask for in that era of pickup. I guess all of those would be benefits if I could get them but mainly I want the quite idle, accurate timing and computer compensation for the environment.

john8662, as to the advance system for the 5.7 there were two options. The 78-~80 pumps were basically speed advanced. The faster you turn them the more advance they had. Then when the DX debut the advance piston was added to the pump and it is almost identical to the 6.2 pump. As for the firing order issue that should just be a matter of routing the right injectors to the right ports on the IP and I'm not sure on this but I would guess the 5.7 lines are already setup correctly for direct swap since it's just a rotary distribution. I'm basically down to figuring out a drive system for the pump and getting the sensors to report the right data to the PCM.

JohnC, I totally agree with your statement "If you're looking for a long, drawn out, controversial project, i think you've hit the nail on the head!" Easy isn't in my vocabulary. On our ranch, while I was in High School we built a 75 Chevy 1 Ton pickup (yes pickup, not truck, no typo) with a 3208 CAT shoe horned into it, Allison transmission, etc. We also dropped a 4-53 T Detroit Diesel into a 73 Ford 3/4 ton with a 5 speed Clark and Gear Vendors. Fabrication, torch, welder, Bridgeport mill, all flavors of saws, plasma cutter, etc are all common vocabulary.

Great info and contributions guys, I think everyone at least agrees this is going to be an enormous undertaking but I think I'm going to attempt it if for nothing more than the "It can be done" factor. Think about it, I'm playing with a 5.7 with work done to it that most speedshops would shake their heads at... It's a novelty, it's fun, but it's for sure not everyone's cup of tea.

[JohnC]

Fabrication, torch, welder, Bridgeport mill, all flavors of saws, plasma cutter, etc are all common vocabulary.

None of these are going to help with the electronic pump! ;)

I guess I assumed you have a turbo. That's the only thing that will save you at altitude. The DS4 pump can't do anything more than you are doing by backing out of the throttle. What you need is more air, not less fuel!

I'm no 5.7 expert, but if it's got a DB2 pump, then I'd expect the DS4 will bolt right up. Firing order is irrelevant. All injection pumps fire 12345678. the difference is in the lines to the injectors, just as with a distributor. Just put the wires on the right spark plugs...

The DB2 6.2 and 6.5 engines did not have any electronic control of advance. It was purely mechanical. What I think you are referring to is the HPCA solenoid, which advances the timing for cold starting. It is on or off, though, not stepped.

If you're dead set on doing this, I'd find a 94 or 95 standard wreck to start. that way you won't need to mess with any transmission control logic.

And get a turbo!


for 14.7 PSI boost you add 1 ATM so at sea level you'd be feeding the engine 2x the air. Only way to make use of that air for power is more fuel. More fuel going the same speed = less economy. Even at 4-5 psi boost you'll see on the road you're using 20-30% more fuel.

This is not completely true. A Diesel makes more power if you add more fuel, so you will not go the same speed. In fact, under some conditions, the turbocharged engine makes more power on the same fuel due to more efficient burning. It's not like a gas engine, where if you add more air you need more fuel just to keep it running smoothly. The 6.2 NA engine gets better mileage than the 6.5 for other reasons, like smaller pre-combustion chambers.

Carry on!