Join Date: Jul 2006
Now get yourself some good ziplock bags, and use them to hold the bolts you remove. Keep them in groups, like for the intake and the alternator bracket. This helps tremendously when putting it all back together. Some of my bags only had 3 bolts in them.
Originally Posted by CaptCrunch
Can someone help me out with instructions on replacement of a '95 injection pump? Scans? Haynes?
Unplug wire harnesses as you need to, but label BOTH ends. GM makes it hard to plug up the sensors wrong, but why take a chance. A small tape flag with "A" "B" "C" and so on, on both sides of the plugs make it easy later.
Remove the upper and lower intakes seperatly. Getting the intakes off is not as daunting a task as you would think. Make a sketch of what holes hold bolts and what holes hold studs. Dont forget to unbolt the fuel filter, You dont have to remove it, but it has to come off the intake. A 15mm deep 6 point socket and a speed handle makes the job pretty easy. Dont unbolt the coolant crossover. It can stay in place. Stuff a shop towel into each intake port to keep anything from falling down into the engine.
Once the intakes are off, you will see the pump, and you will dispair at getting the injector lines off. Follow the line back from the #1 cyl, and mark it at the pump. It should be on the drivers side of the pump, just above halfway down. I use a small zip tie on the nipple to mark it, just so you dont loose track of the #1 spot on the pump.
Remove the #1 and #3 line nuts at the injectors and remove the #1 line nut at the pump with a 3/4" wrench. Carefully slide (DONT BEND) the #1 line back in its bracket just enough to allow the wrench to fit on to the #3 line nut. Remove the #3 line nut and remove that pair of lines from the truck. LABEL EACH LINE NEAR THE PUMP END!
Now you can remove the line nuts for the lines on the top of the pump (8-7-2 and 6). If you undo the lines at the injectors, you will find you can move them a little for wrench clearance. I wound up leaving the 6-8 pair attached to the injectors, because getting to them was a pain in the @ss.
Before getting the bottom 2, I removed the cap over the fuel solenoid, and undid the wires. Getting the lines off is not fun, but its not impossible. You just got to work at it.
as each pair of lines comes loose, remove it from the truck. (you did label them, right?)
Now comes the fun part. It helps to have nerves of steel.
Remove the oil fill tube and grommet off the front of the timing cover. Inside you will see a large nut and hopefully some smaller nuts. You may have to rotate the engine. Use a 15mm on one of the damper bolts and turn in in the 'tighten' direction. Grab some help, and give them a mirror and a light and have them stop you when one of the smaller bolts is inline with the oil fill hole. Remove this bolt. and rotate the engine again. Repeat until all three bolts are out.
MAKE DAMN SURE YOU DONT DROP THESE BOLTS INTO THE ENGINE. In this one area, you want to work slowly and cautiously! As soon as the bolts were finger loose, I stuck my finger in the hole and used my fingertip to make sure the bolt stayed in the socket. Painful, but worth the effort.
After all three bolts are out of the gear, you may remove the 3 nuts holding the pump on. First scribe a line on the pump bracket that lines up with a distinctive part of the pump. It does no good to draw a line on the pump and bracket if you are replacing the pump. there is a part of the pump flange that angles down, I used that as my reference.
Start at the one on the lower passenger side. It is the hardest to get to, and you might as well get it while you are fresh. I used a standard 15mm wrench with no modifications. You may want to bend or grind on the wrench for clearance. It may make it easier, but its not neccisary. Then get the drivers side nut, and finally the top one. With all three nuts off, now the pump will slide out. Remove and discard the gasket.
I'm not sure if you can pull the timing gear out of mesh or not, but I dont think you want to find out. BE VERY CAREFUL AROUND THE TIMING GEAR!
When installing the new pump, rotate the pump so the index pin in the gear hub is aprox. in the same place as the old pump. NOTE! GM, in their infinate stupidity, put the index pin in the same bolt circle as the bolts. This means its entirely possible to stick the index pin through a bolt hole and you wont know it until you try to install the gear bolts and nothing lines up. I had the pump and all lines on when I relized that I did JUST THAT! Talk about excessive profanity!
For that reason, I recommend putting on the top pump nut to hold the pump in place, and then the gear bolts, before doing anything else. I used blue locktite on those bolts. I found using a small mirror to help get the bolts lined up with the holes helps alot.
Install the other two pump nuts. How, you ask? Simple (sort of...) I use a coat hanger to fashion a long wire with a small hook. I hung the nut off the hook and used a long screwdriver to start the nut on the threads. Its not easy, and can frustrate the hell out of you, but if you stay with it, the nut will eventually start. Have a magnetic pickup handy for when (not if) you drop and nut and have to fish it out from underneath the pump in the engine valley.
Once the pump is line up and the 3 nuts secure, go about re-attaching the bottom injector lines on the pump (now aint you glad you labeled everthing?)
the firing order is 1-8-7-2-6-5-4-3. Repeat this mantra every time you install a line, checking and rechecking over and over.
Once you got the bottom lines hooked up, install the Fuel solenoid wires and cap, and reattach the remaining injector lines.
Once I had all the injectors lines on and wires hooked up, I removed the shop towels and tried starting the truck. A 6.5 is more than happy to start and run will the intake off. I DO NOT recommed this unless you have balls of solid rock. You could very easily suck something into an intake port and do something dreadful to the motor. I did this just so I could check for leaks and whatnot before putting on the intake.
It took some cranking but it finally started. It took about 30 seconds to purge all lines and settle down into the familiar 6.5 idle. Everthing looked good, so I shut it off and installed the intake, alternator brackets, oil fill tube, and anything else that I had removed.
A quick road test confirmed that everthing was okey-dokey. It is conventional wisdom that you should re-time the pump anytime you mess with it.
I got this from another post. hope this helps
2013 GMC DENALI HD Z71.
1995 Chevy C2500 6.5TD excab longbed bone stock minus the cat, heath diesel pmd relocation kit, DIY turbo master, OPS Relay, K&N Cone Filter. Still a driver at 270,000 miles on the odometer.
Stirring the pot club member #1