IP Install Question

[Dave Barbieri]

On my 94 1Ton, the injection pump drive gear is held on the pump drive flange with three bolts. Along the edge of the flange, there's a slot and on the opposite side there's a hole. Does the pin on the drive flange go in the hole or in the slot?

This afternoon, when I pulled the injection pump off, the pin was in the slot. I didn't even notice the hole until after I had the pump off. I'm wondering if the pump could have been installed 180 out.

 

[97gmc6.5]

On my 94 1Ton, the injection pump drive gear is held on the pump drive flange with three bolts. Along the edge of the flange, there's a slot and on the opposite side there's a hole. Does the pin on the drive flange go in the hole or in the slot?

This afternoon, when I pulled the injection pump off, the pin was in the slot. I didn't even notice the hole until after I had the pump off. I'm wondering if the pump could have been installed 180 out.

Yea the pin goes in the slotted hole. The round holes are for the three bolts

 

[Dave Barbieri]

Yea the pin goes in the slotted hole. The round holes are for the three bolts

You're right. I checked one of our online info sources - Mitchell On-Demand. The pin goes in the slot. What had me stumped last night was the 4th round hole. It's smaller diameter than the three bolt holes and located directly across from the slot (180 degrees out). My 94 GM shop manual set doesn't have the diesel engine supplement, so I had no pictures to go by. The diameter of that hole looked like a perfect fit for the drive pin, and I was worried that it might have been installed wrong by the last guy that worked on it. It was pretty obvious that this has been disassembled before. The IP that was on the engine didn't match the chip in the ECM. No bolt on the lower passenger side stud, and one of the drive gear mounting bolts was hand tight.

Well, the batteries have been slow charging since last night. I'm taking one of our Snap-On MT2500 scanners home with me. I think I'll hook it up and see if I get this puppy to light off.

 

[97gmc6.5]

You're right. I checked one of our online info sources - Mitchell On-Demand. The pin goes in the slot. What had me stumped last night was the 4th round hole. It's smaller diameter than the three bolt holes and located directly across from the slot (180 degrees out). My 94 GM shop manual set doesn't have the diesel engine supplement, so I had no pictures to go by. The diameter of that hole looked like a perfect fit for the drive pin, and I was worried that it might have been installed wrong by the last guy that worked on it. It was pretty obvious that this has been disassembled before. The IP that was on the engine didn't match the chip in the ECM. No bolt on the lower passenger side stud, and one of the drive gear mounting bolts was hand tight.

Well, the batteries have been slow charging since last night. I'm taking one of our Snap-On MT2500 scanners home with me. I think I'll hook it up and see if I get this puppy to light off.

Sounds good! i think the Mt2500 reads the TDC offset at 5.4. Different then the Tech II -1.94

 

[Dave Barbieri]

Well, the MT read 18.2 for indicated and actual timing. I'll need to go back and loosen the injection lines to set the timing where it needs to be. Cranking speed was back down to 75rpm. (dang!) Thought I had that resolved with the new baterries, cables and grounds. I'll probably hafta wait til this weekend to really troubleshoot that. Hopefully, it's a starter going south. Not a bearing. Or a seized ring/scored cylinder wall. Or a warped crank. crap.

 

[97gmc6.5]

the timing will be advanced when the engine is cold.
I let mine warm up to 75c ect on the scanner and then exit engine data and go in to time set then the des will go to 0.00 and set the actual about 3.5 degrees timing
then you can do the koko (throttle to the floor key on for 45 sec then key off let off throttle for 30 sec and that will relearn the TDC offset to -1.50 to -1.94
if you did not know that! i'm having to learn all this the hardway!

 

[Dave Barbieri]

I mooched an amp probe from the shop and checked starter current draw. Engine cold, with all fuses pulled (so the starter's the only thing pulling power), the starter pulls 475 amps. I compared this to my 1985 Ford 6.9L which pulls 265 amps under the same conditions. Two possible options here: 1) The engine is hard to turn over and the starter is struggling. (bearings, scored wall, etc) 2) The starter itself is dragging - bad bushings allowing the armature to drag against the field coils. Next step will be to use a torque wrench to turn the engine over. With the injectors removed, max torque on a non-loaded engine should be around 25# (drag racer's rule of thumb). Without going to the trouble to pull the injectors, I'll hafta fudge a little. I'll also pull the starter and run a bench test. Chevy's specs are 130 amps @2300 rpm.

the timing will be advanced when the engine is cold. I let mine warm up to 75c ect on the scanner and then exit engine data and go in to time set then the des will go to 0.00 and set the actual about 3.5 degrees timing then you can do the koko (throttle to the floor key on for 45 sec then key off let off throttle for 30 sec and that will relearn the TDC offset to -1.50 to -1.94

Yeah, I figured the cold start advance would be kicked in. I'm still studying/learning the timing procedure for OBD-I. Seems to be mostly manual - the pump is adjusted 'close' and then the ecm kicks in and electronically fine tunes the timing. I understand I need to have the pump set pretty close for this to happen. If the pump setting is too far off, it simply won't fire. Also (back to the starter issue), if the engine is turning over too slowly, the pump won't build sufficient pressure to fire the injectors. At 75 - 100 rpm, my IP is turning less than 50rpm. I understand from my pump shop that it needs to be at least 75 rpm (150 rpm engine cranking speed.)

if you did not know that! i'm having to learn all this the hardway!

Don't get me started on the learning curve stuff!