Is the rack in my Injection Pump moving correctly?

[Fonzi]

Parts car 07/1969 build 280se, and I’m just trying to get the motor running before removing it from the car. 

A friend of mine noticed that it looks like maybe the rack is not moving enough.  I am trying to learn these because I have another 250se in the garage that I’m trying to fix up.

I’m willing to pay for a membership here if that helps in getting assistance.  It seems like finding info on these pumps isn’t easy to come by.  My friend Bob Youngman has been very helpful through rebuilding my fuel pumps. 

I decided to take the IP off the car after the back three injectors started firing and the front three would not.  Compressed air into cyl 4 port changed the behavior a bit, inflating my fuel bottle sometimes.  It turned out the plunger moved, but the spring was stuck.  I got it unstuck. 

Now checking if the rack is ok, and then trying to determine if the timing was anywhere near correct because this pump was clearly off sometime in the past, and hasn’t been on the road since 1986 based on the inspection sticker.

https://youtu.be/dW-GJz8ZSiE

Does that look like correct rack movement? 

[Fonzi]

I am going to document my issues in this thread.

And when reinstalling the pump, I will follow the procedure here, but first need to see if my pump is ok to even reinstall.
FIP Timing: https://www.sl113.org/forums/index.php?topic=12659.msg85895#msg85895

(Last I was getting fuel out of injectors 1, 2, and 3, and I guess the 4 plunger was stuck, but was still getting no fuel from 5 or 6 despite them moving ok.

[Fonzi]

I learned that the brittle plastic cap that started cracking and chipping when I tried to remove it is an access to test the rack movement.  I removed the cap, and here are my measurements with my bolt:
- resting: 32 mm from housing
- pull out: 34 mm from housing
- move throttle linkage to max: 34 mm from housing.
- push in: 15 mm from housing.

So it moves 2 mm out from resting, and in 17 mm from resting.

 

[Fonzi]

Jamie Kopchinski has much more outward motion than me.  Maybe mine is adjusted to toss too much fuel at idle?

https://youtu.be/QYF04sW27us

[Peter h]

https://youtu.be/o6yWnorhFcU
Peter

[Fonzi]

https://youtu.be/o6yWnorhFcU
Peter

Thank you Peter H.  In that video, it just looks like they pushed the rack bolt in, and quickly removed it allowing the rack to return to its resting position.  My rack would do the same with about 17 mm of movement on the test bolt.  With this, I will assume that my rack is operating properly. 

[Fonzi]

Trying to document what IP I have: 

Tag on the LEFT:
-----------------------------
90620680
PES6KL 70B120 R20 Y     (P could be a B or possibly an R)
0408 026 017
----------------------------

Tag on the Right:
EP/RLA 1/18 R

[Shvegel]

Rack and pistons are interrelated.  the rack turns the pistons to adjust fuel so a stuck piston means you rack is stuck as well.  That being said they usually don't move so that is odd that you have so much movement. Basically if number 4 piston is stuck you need to free it up.  This has been covered a bunch here so search stuck injector piston and you should find what you need.  If I were unsticking it I would do whatever I could not to remove the outlet fitting.  It is a long story but try laying the pump on it's side with the side cover up, Removing the side cover, remove the inlet fuel fitting (closest to the front of the engine on the same side as the side cover.) and fill the inlet with lacquer thinner.  One you have done that try moving the piston up and down with something that won't scratch it like a popsicle stick etc.  when it is free poking on the rack end should allow the rack to move freely and you should see movement through the side cover.

[Fonzi]

Rack and pistons are interrelated.  the rack turns the pistons to adjust fuel so a stuck piston means you rack is stuck as well.  That being said they usually don't move so that is odd that you have so much movement. Basically if number 4 piston is stuck you need to free it up.  This has been covered a bunch here so search stuck injector piston and you should find what you need.  If I were unsticking it I would do whatever I could not to remove the outlet fitting.  It is a long story but try laying the pump on it's side with the side cover up, Removing the side cover, remove the inlet fuel fitting (closest to the front of the engine on the same side as the side cover.) and fill the inlet with lacquer thinner.  One you have done that try moving the piston up and down with something that won't scratch it like a popsicle stick etc.  when it is free poking on the rack end should allow the rack to move freely and you should see movement through the side cover.

Thank you.  So this might explain why after putting injectors on the lines after all six were pumping fuel, I’m still not getting a spray out of injector 4.  I assumed that if the spring and plunger are moving up and down, then I’m good to go. 

Can you see the videos I took in the first post? 

I’ve now got the IP back in the car and was trying to get it started yesterday.