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View Full Version : DS4 to DB2 Mech. Injection/Part 2



DickWells
07-25-2004, 17:43
Well, did I make my original question too long, or somehow upset someone? It's now on page 2, with no responses.
Trying again, here's where I am right now. Waiting for the new timing sensor for No. 1 injector line to come in.
Thinking now that the way the thing is acting, (running real rough and blowing lots of white smoke regardless of the pump timing position), that I may have the throttle pivot cam-driven advance stuck in the full advance position inside the pump. The local Chevy dealer has a 93 one-ton in the shop that has that problem right now. Anyone out there had experience with that kind of thing?
I may have to take the pump (4911 with marine internals) back out and go back to the Stanadyne place and have them test it. If you read my other note, you'll see that I've had it for a year, now and just getting around to put it in.
Any advise from the experts out there will be greatly appreciated.
Thanks.
Dick

markrinker
07-26-2004, 06:55
Why did you decide to 'revert' to mechanical injection over electronic? Will the mechanical pump flow more fuel when turned up?

HANK1948
07-26-2004, 17:07
the DB2 pump can be turned up easaly and make more power than the DS4 pumps, and more reliable , alot less to go wrong with no sensors to worry about, and alot cheaper to repair. any 6.5 that makes alot of power probaly has a DB2 pump, the project 300hp 6.5 truck has a mech. pump. I f it wasnt so involved I would turn my truck into mech. injection in a heartbeat.

DickWells
07-26-2004, 17:34
Thanks, Guys, for your notes. But, I still have a 6.5 that runs real bad, and I'd like to hear from someone who has experience with that internal (infernal?) advance mechanizm in the DB2 pump.
John K. told me last week that it's best to stick with the electronics, if you can get the FSD to keep working right. I have a remote, cooled FSD and haven't had any problems for quite a while. They say not to fix something that ain't busted, and here I am, fixing a 6.5 that was running quite well! But, the DS4 has over 70 grand on it now, and I never trust anything electronic, anyways.
Please keep those cards and letters coming, and say a little prayer to the diesel deity for me. Come to think of it, that might be Dr. Lee. Well, if it is, the prayers still couldn't hurt.
Thanks.
Dick

grape
07-26-2004, 19:36
how are you shifting this truck?

Bobbie Martin
07-27-2004, 03:41
Originally posted by Dick Wells:
John K. told me last week that it's best to stick with the electronics, if you can get the FSD to keep working right.Well, as there is no way to keep the FSD working right, I guess he advocates switching to a DB2! Did you have the DB2 rebuilt before you installed it? It sounds like something is amiss inside. My suggestion is to remove it and have it bench tested.
The real fun once you get it running right and is finding out how the 4L80E shifts. I've been through this and if you want to email me, I may be able to help you.
For the rest of you, I hope to have an announcement real soon about DB2 conversions!

DickWells
07-28-2004, 17:38
Hi: I haven't read my e-mail today, so I don't know if you've sent me anything yet, Bobbie.
Just gotta mention that I did take the pump out today, and took it down to Burlington Diesel, and they tore it down and inspected it, and then tested it on the computer, again. Couldn't find anything wrong with it.
I'm wondering if I had bled the system well enough last week. I'll get the pump back in and try it tomorrow. The new timing pulse sensor for No.1 pipe is in, so I should have no more leaks there.
I learned that I could have an injecter or two that are clogged. I can check that by putting fuel in the top of an open injecter and turning the engine over. If I get fuel blowing out, I have a clogged injecter.
I also learned that I got a new pump body along with my oversized rotor and head, so I essentially have a brand new 4911 pump.
It put out fuel that bassically matched a DS4 at all RPMs. The internal advance worked just as it's supposed to. So back to trying it again, and take it from there.
Wish me luck.
Dick

DickWells
08-01-2004, 18:33
Hi All: Well, it runs! But good! I have a grin from ear, to ear, that's lasted since yesterday morning.
I buttoned up the little things, like the heat shields around the injecters on the passenger side, and the one on the turbo. Put on the fan shroud, kicked my tools across the floor, and drove away. Everything works perfectly, except the shifting, and even that isn't bad. Right now, I just lift my foot a little at the right shift points, and it up-shifts. Actually, I kind of like the way it hangs in there, ready to put more power to the road. More power is there, too. The mechanical pump is much sharper on exceleration than the electronic job. It's always been a quick starter, but this is tremendous. No glowing when the engine is warmed up, but even cold, just glow it till the light goes out and just bump the starter and it's running. Stumbles for a few revolutions, and then smooths right out.
I think what was wrong last week , was that I didn't bleed it enough, or possibly didn't fill the pump full enough. It kept wanting to run while I fully bled the last few injecter lines. Cleaned out and sat there and ran like a top after I tightened number 8 down.
The shifting? Seems like I have a little too much pull on my cable for the amount of rotation of the EPP sensor. I have a pretty good idea of how I'm going to make that interface ajustable to allow me to get the right relationship between the two, right there at the pedal.
Now, can someone tell me how I'm going to hook up my fast idle solenoid and electrical advance there on the right side of the pump? My coolant sender works on 5 volts, so I can't run them from that. Worst case sceneario, right now as I see it, is to get myself a 12V switched line somewhere under there, and put in a toggle switch, and just use it for start-up, or for as long as I see fit. What do you guys think?
Funny thing. I still have boost control, with no wastegate solenoid hooked up and my original Kennedy boost sensor adjustable pott. I expected to have to go to a mechanical control, after I removed all those wires from around the pump.
I wonder if I'll have an issue with the ECM shutting me down, since I accessed the only 12V connecter at the pump for my fuel shut-off? Time will tell. I just clipped the wires off the DS4, and put a flat female terminal on the hot lead, and a round one on the ground lead, and plugged and screwed it to my DB2.
By the way, the tech who built my pump, put a new tag on the side, and stamped it something like DB2-4911XP, or some such thing. Well, when I walked on it at about 25 mph on hard packed gravel, and had it squirt ahead and leave twin streaks behind me, with about 800lbs in the back, I kind of feel like maybe it should be called an XP. I'm not used to the old Sub getting up and going like that.
Thanks for all your support, fellas.
Dick Wells

More Power
08-02-2004, 12:17
GM uses a thermal switch that screws into the rear lower corner of the passenger side cylinder head to control the cold advance and fast-idle solenoids. This thermal switch is powered by an ignition source on one terminal, with a wire connected to the second terminal running up to the injection pump solenoids. It sends power to the solenoids at engine temps below 95 degrees.

I recently received a complete literature/CD package and a working example of a 4L80-E aftermarket powertrain computer/harness set. The company thought we might be interested in their product for use when converting to mechanical fuel injection or for installing an electronic transmission (either 4L60-E or 4L80-E) in a non-electronic truck. Their kit isn't all that expensive, and a summary/overview will appear online here in The Diesel Page before too long.

MP

rjwest
08-02-2004, 12:50
Great Post !!!!

DickWells
08-03-2004, 18:05
Yes, good post, Jim. Thanks. I'll be very interested in that harness for the transmission.
The heat sensor, I could use right now. Think I'll go over to the Chevy dealer and have them look one up for the 93, or earlier. I'd like to get one in there.
I was going to start a new post on the way my rig is working, I'm so happy, I hate to leave it and come in when it gets dark out! I've got the thing shifting (almost) as it did, stock. I made an adjustable, roller activated hook-up at the pedal to interface between the APP module and the cable.
Took it out tonight for a spin, and found that my earlier assumption of the APP having to tip in, in advance of the cable was wrong. Couldn't get out of second gear. So, I came back to the garage and took a 1/2" wrench, and rotated my adjustable plate with the roller to just contact the cable push plate, thus taking out all of the APP advance ahead of the cable. Took the Sub back out on the road and (Lo and Behold), it shifts!
I don't think the shift points are exactly as before, but they seem much more; What's the word?;, (useable?). Boy, does the thing like to go, now. Never have had it so ready to accelerate. Everything seems to feel so much sharper, and quicker.
If the throttle thing keeps on working for me, I'll take it back out and take some pictures, and make some drawings. Then, at some point in time, I'll have someone teach me how to send photos to the DP.
Jim,I still don't see how that mechanic in Texas that you mention in the DS4 to DB2 - Part 2 article in your book, could just weld his throttle cable arm onto the APP module arm and have it work. Was there a difference in the year of manufacture, perhaps? I found that I had to incorporate an adjustable ramp/plate (adjustable for pitch angle), along with another plate with a roller on it that also can be adjusted for contact angle, in order to get the two units to activate in any where near a linear fashion. Best thing is, my unit makes use of the old plastic bearing block, somewhat like is pictured in that same article.
Thanks to all of you for bearing with me through this. I wouldn't even know that it could be done, let alone be able to do it myself, if I hadn't stumled onto the Diesel Page in a four wheeler magazine, back in 99.
Boy, am I going to sleep well tonight! Crack-a-dawn, I'll be out there taking another spin, just to see if it's still real.
Thanks again.
Dick