Thanks for all the great post. I have ordered a new IP. will install this weekend. I have had this truck about 8 months. First diesel. Changed all oils and filters right off. Had been Running great, than last Monday. Stalled, Check eng light and check pedal soon. would start right back up. No codes. As it got to running temp would hardly run Got home and started reading Web. lift pump seems ok . Check all connections I could find. pulled connector on Crack shaft senser would sart no power but ran. I think it is th PMD. With 120,000 miles I decided to change the Injector pump as well. I should change the injectors but that will have to come later $$$$$ ;( . I could use any help on changing the Injector pump, I do have the GM manuals. I will post all results. Thanks JoeEdited by: joefenderman

What year is your truck Joe?

94 with the green tag pump Everything stock. I think the pump has been changed before the lock on the connector is broke.Edited by: joefenderman

Have you:

looked at the air/fuel filters, fuel quality or lift pump operation?


Edited by: quantum mechanic

I have just change the fuel filter less than 1000 miles Air filter looks good. don't know about the fuel . I did add fuel injection cleaner last fillup it said for diesol only . I have read a post that said never use anything that say's cleaner. Lift pump look ok when bleeding air after filter change.


JoeEdited by: joefenderman

you read my post and you still did it anyway...http://dieselplace.com/forum/smileys/Shocked.gif Edited by: Texas Diesel Guy

no read it after

HEY TDG


How much would it cost to get a Right built IP for my 95 6.5. My is still working great but you seem to have a ton of knowledge on these pumps and it sounds like there is alot that can be done internally.

Re and Re on a DS pump in a truck is not bad, we've got it down to about 2-3hrs depending on year model, 94-95 being the easy ones. Of course air ratchets and experience help a lot. For a first timer, with out air tools, expect to spend double that. As far as tips, being your first time I would carefully note the alignment of the timing marks on the pump/block before you remove it, and try to get close to that so you will atleast be in the ballpark, also, if you have a good size vice to hold the pump when you get it out (being very careful not to damage it), I would remove the pump with the high pressure lines, unscrewing them at the injectors. Save you a lot of time if you can do it that way, hard to reach the lower half of the lines on the pump without the right wrench, and harder to fish the pump out with the lines in the way. When you get it out, just swap the lines over to the new pump and put her in, making sure you put the pin in the slotted hole on the drive gear. Edited by: Texas Diesel Guy

Thanks TDG . Were are the timing marks? I do have air tools. After intalling the IP do you need to bleed the air out of the lines at the injector? Will I need to have someone with a scan tool set the timing?


I wish I would have saw your post on the cleaner before. I just though I was doing PM. With my car adding injector cleaner really helps. Now I know the systems are totally different. does the cleaner remove the oil in the IP? Will it hurt my new IP?


Thanks for the help.Edited by: joefenderman

at the front of the pump right above the upper mounting bolt there will be a line scribed in the pump housing, and one also on the timing cover on the truck. Just get them close to where they were so you will be in the ballpark, if anything, just slightly advanced from where they were (pump tilted slightly towards driver's side) as there will be some slack in the timing chain.


Loosening a couple lines, usually the front two on the driver's side because they're easiest to get at, will help bleed air out of the system and get the truck started faster.


All diesel fuel systems, unlike gasolines, rely on fuel for lubricity to keep moving parts from binding, scarring eachother. If you want a cleaner fuel system, then check/replace your fuel filter regularly, if you want to preserve it, put in a lubricity additive. Most fuel system 'cleaners' I've seen also say they remove water from the system, and usually contain either alcohol or methyl hydrate, so now whatever water you have in your system will now be able to mix with the fuel and go right past your water in fuel sensor and into your IP/injectors. So now you've got water in your pump, which will be seperated like a centrifuge since water is still heavier, this water will cloud your fuel, rust moving parts causing them to drag/scar/leak and it will pit the nozzles in your injectors and can even knock the tips off of them.


In a gasoline, multi-port fuel system, with a rail pressure maxing at about 30psi and injectors that might as well be squirt guns, works fine. But in a diesel, injector opening pressure is now 1700psi(6.5) and up, and they don't 'squirt' fuel into the engine, they actually atomize the fuel breaking the molecules themselves apart.

Joe, the 6.5 electronic pump has no timing marks nor does the block. It's a whole lot easier changing the pump by leaving the lines on the engine. You will need an offset 3/4" open end wrench to get to the bottom lines. Do it this way and you won't have to fight the turbo. Just make room in the frig for a twelve pack so you and your buddies can tackle it. Need a scan tool to time it right but many pumps have been installed without it.


Just my $0.02 worth Edited by: Diesel Pro

most have timing marks, if they're there just use them as a ballpark reference, if not, guess and let the scanner walk you in.Edited by: Texas Diesel Guy

Joe,
If you're willing to change the pump, you should try taking the cover off the IP and see what the fuel looks like in there.
Then you could try cleaning the low res optic and the black one above it with a mild solvent like alcohol.
you can see the relative timing the truck was running by the approximate location of the sensor. to the passengerside is retarded and to the drivers side is advanced.

TDG,
The '94 was running hot today first time in a long time.
Is this what a rusty ventwire does?
Where did you say I should go to buy one?
I do remember that I want the lowest number wire.
What's the green tag on the pump mean? also a blue mark on the optical connector.

DP,
My '94 has timing marks on the block and it's green tag pump.Edited by: quantum mechanic

QM, possible the truck is running hotter if you advanced the optic sensor even further than it was, Vent Wire not likely to be the cause as it only helps cool the pump, not the engine. Local Diesel Fuel Shop will be the only place to get one (Stanadyne P/N 21662). Back in the old days DS pumps went through a series of updates and label color and tags were used to mark the changes...Black Label pumps were the originals, but odds are you will never see one, they've all been either warehoused or destroyed. Blue label came next with some early improvements, green tag was next with ceramic rollers and updated optic sensor, which is now obselete. Green tag now, means the pump is old 5288 gen, but if it still works, well, your doing something right.

Perhaps some blocks do have timing marks as they made a lot of 6.5's with mechanical pumps. The electronic pumps have no timing marks as there is no way to put one there nor is there a spec for it. If you put to low a vent wire in the pump you could create a hard start problem hot. The vent if mainly use to get rid of the air bubbles in the fuel, especially when changing filters or running out of fuel. To much return will reduce the cranking fuel pump pressure by bleeding this pressure off. Something you have decide for yourself.


The different color tags blue and green indicate the pump has had an on going update done to it. Blue was one of the first and green the later version. Tags mean little now as most have all been superseded.


The encoder has gone thru many changes and it seems every other month there is a different code marking on it. Could be just date codes. Factory only knows.

Transfer pressure spec at cranking is only 16 psi, I've never seen a DS pump that wouldnt put up 30 with a #2 vent wire. On a side note Diesel Dan, have you seen the new Stanadyne Red Nameplates??? I'm gonna pull the pump on mine just to put one on it! Thats gotta be good for another 5Hp http://www.dieselplace.com/forum/smileys/Big Smile.gifEdited by: Texas Diesel Guy

Hi Guys thanks for all the info. The more the better. I been reading my Gm manual I think I 'll be ready. Timing is one thing I am not sure what to do yet, Maybe if it runs well I won't worry. I might just invest in a scan tool I would like one that works for my 88 Transam as well. Any good books on the 6.5 operation?


Thanks again Joe


BTW DP Beer is on iceEdited by: joefenderman

Field Expedient Timing for GM 6.5 Electronic:


Tools needed: flashlight, 15mm Wrench and whatever else you need to loosen mounting bolts and tilt the pump.


Procedure: With engine warmed and truck idling, look just over the radiator, under the coolant crossover at the foot of the Stepper motor. When the foot is fully extended it will appear to bounce slightly side to side as it is again the limit of travel, this means the stepper is at full retard which means the pump is too far advanced. Retard timing until stepper is just above full extension at idle, or advance it until you reach the same point.Edited by: Texas Diesel Guy

TDG,
Could you show the stepper you're looking at in a picture?

The stepper motor is on the drivers side of the pump, opposite the PMD, or in your case QM, where the PMD was. You should be able to see it without removing anything, but it will be very easily visible with the intake tube removed. Just take a flashlight and get where you can see the foot protruding from the bottom of it.

Here is my IP from the drivers side.
http://www.dieselplace.com/forum/uploads/628_Ip.jpg
I'm still not clear about where to look.
Is the allen screw the ventwire?

ummm....my keyboard messed, I'm sure I typed passenger side, but some how it came up drivers, sorry.


For the vent wire, its under the top cover, at the back of the pump, you will see a small hole drilled straight down between the optic sensor and the back of the pump.Edited by: Texas Diesel Guy

This is the passengerside.
http://www.dieselplace.com/forum/uploads/A49_ip1.jpg
Can you point it out in this pic?

That's the stepper motor with the black plug on it. Don't see any timing marks on the pump. Good Pictures.

yeah yeah, I never said there was a spec, but a lot of the pumps have been scribed by someone at some time. Mark it when you take it off and do the next guy a favor ;)


QM, yeah its that silver pod on the side with the black plug in the top, on the bottom you will see a boot and a foot sticking out that moves a lever inside the pump to control the advance.

Thanks, I must have a little missouri in me and you have to "show me".
http://www.dieselplace.com/forum/uploads/AEF_ventwire.jpg
I think this is the vent wire.Edited by: quantum mechanic

TDG I installed mine yesterday. I didn’t have time to finish. Took about 3 hours. Most of the time was spent making sure I was doing the job it right. I did have a mark on my block but not the pump. OEM manual did tell me to mark both the block and the flange on the pump. Diesel Pro I did remove fuel lines on the block a little bit of a pain but easer than removing them. Deciding the best way to remove the bolts on the pump gear took studying. I decided to make sure the last bolt I removed was the bolt next the locating pin that way I could bump the starter to get to each bolt. Before I removed the last bolt I did mark the pump gear and the cover plate not sure if I need to but I wanted to make sure the pump gear did not move. If I understand the timing if my steeper motor is not bottoming out and no codes. The computer should be able to adjust the timing correctly. I am wondering if this will be the best timing or just with in spec. I know with gas fuel injection Pre 95 computer. The computer will adjust the Distributor timing only if it sees a problem. But you can do better if you advance the time until the car pings than back it off this will give you the best timing. I know they are different systems but from what I am learning the computers have about the same brainpower. Anyway just a thought. Just some R&R I should be running. Thanks everyone for all the help JoeEdited by: joefenderman

Its not an exact science, you still need a scan tool to fine tune timing, the method I described is just a way to get it close enough to operate. The only similairity you can apply to this engine from a gasoline is that if you have the pump too far advanced where the stepper is bottomed out they you will have noticeable more detonation clatter at idle, and if its more than a couple degrees too fast, you will get stepper motor or cam/rotor codes.

Will the truck is running again same problem. I rellalize the truck does not seem to stall only goes to idle . The service engine light and serive throttle soon light come after less than 30 seconds lights go out truck. I have checked all grounds I can find. I didn't get any codes before. This time when I got everything back together I left the cranks senser unpluged so when I started it service light came on . when I pulled the codes I had 19 and a 26. Reconnected CPS no codes. Is my pedal going bad. With 1 failures should I not get service engine light and a code 26 and if 2 go out service engine light service throttle soon and limp mode and if all 3 go out service engine light service throttle soon and idle Ideas?


Thanks Again.Edited by: joefenderman

I'm confused, did you plug in the CPS? Try a new one?
The throttle is the black module on the side of the pedal.

Yes with reconnect CPS truck had no codes but will Intermittently (a lot) go to ide and the service engine service and service throttle soon lights come on after less than 30 seconds the lights go out and the trunk is normal, From reading my manual the serivice throttle soon light comes on and the truck goes to idle should only happen when all 3 TPS's fail. I had found the TPS wiggle it bet on it checked grounds. Is my TPS bad? thanks for the help. I going to start a new topic. Edited by: joefenderman