Uneven Injector Output ***Split from PPR Shim Source ***

[bytes311]

Thanks for sharing your documentation, Ron!

Here are my part numbers:

Warm-Up Regulator: Bosch 0 438 140 066 20190508_170804.jpg
Fuel Distributor : Bosch 0 438 100 076 20190508_065135.jpg
Metering Unit: Bosch 0 438 120 132 052 mixture.jpg

I removed the extra shims and put the fuel system back together for now. I think when it ran at 70 PSI it knocked loose some varnish trapped in the FD because there was a bit of yellow gunk on the WUR inlet screen. That screen was clean before I started pressure testing the system.

Edit: The tank is clean of debris as well, so it must have come directly from the FD.

[MikeWard]

Couldn't find where that came from...I'll look more later.
Meanwhile check this out:
"In order to fully seal off the control-pressure circuit with absolute certainty when the engine has been switched off, and at the same time to maintain the pressure in the fuel circuit, the return line of the warm-up regulator is fitted with a check valve. This (push-up) valve is attached to the primary-pressure regulator and is held open during operation by the pressure-regulator plunger. When the engine is switched off and the plunger of the primary-pressure regulator returns to its zero position, the check valve is closed by a spring (Figure 17)."

Attachment 59986
(Bosch, "Gasoline Fuel-Injection, System K-Jetronic, Technical Instruction", Pg. 20-21.)

The 3rd o-ring is for the check (push-up) valve and it is all about rest pressure, no?

If we're talking about the same o-ring then I believe it is the o-ring at the end of the pressure regulator assembly (circled below) which is responsible for sealing off the flow when the engine is turned off.
pressure_regulator.jpg
Operation of the regulator is briefly touched on in this video which gives a high level overview of the K-Jetronic system. https://youtu.be/a4fJAfXYxWk?t=345

The operation of the CPR is also covered a little later on in that video: https://youtu.be/a4fJAfXYxWk?t=787

It is well worth watching the entire video for those who have 20 minutes to spare and want to get a basic understanding of the operation of k-jet.

Thanks for sharing your documentation, Ron!

Here are my part numbers:

Warm-Up Regulator: Bosch 0 438 140 066 20190508_170804.jpg
Fuel Distributor : Bosch 0 438 100 076 20190508_065135.jpg
Metering Unit: Bosch 0 438 120 132 052 mixture.jpg

I removed the extra shims and put the fuel system back together for now. I think when it ran at 70 PSI it knocked loose some varnish trapped in the FD because there was a bit of yellow gunk on the WUR inlet screen. That screen was clean before I started pressure testing the system.

Edit: The tank is clean of debris as well, so it must have come directly from the FD.

Thanks for confirming the part numbers.
After you removed the shims that you'd added, what did it reduce the primary pressure to?

DeLorean - 2.8 PRV B28F Bosch part numbers for reference:
-DeLorean Fuel Distributor: 0-287-402-023
-Delorean Control Pressure Regulator: 0-438-140-066
-DeLorean Air Metering Unit: 0-438-120-132
-DeLorean Ignition Distributor: 0-287-402-023
-DeLorean Fuel Injector: 0-437-502-022

Parts wise the odd one out on your car is the FD (assuming the other components the above list are stock DeLorean), the other parts match up to stock DeLorean. That's not to say that the Volvo FD won't function correctly - I myself am running a full set of Volvo fuelling on my car, it can and does work, and works well!

[Patrick C]

Thanks for sharing your documentation, Ron!

Here are my part numbers:

Warm-Up Regulator: Bosch 0 438 140 066 20190508_170804.jpg
Fuel Distributor : Bosch 0 438 100 076 20190508_065135.jpg
Metering Unit: Bosch 0 438 120 132 052 mixture.jpg

I removed the extra shims and put the fuel system back together for now. I think when it ran at 70 PSI it knocked loose some varnish trapped in the FD because there was a bit of yellow gunk on the WUR inlet screen. That screen was clean before I started pressure testing the system.

Edit: The tank is clean of debris as well, so it must have come directly from the FD.

I will be selling a complete, 100% working K-Jet system that I just removed from my car last weekend. If you think you might be interested, PM me.

[bytes311]

After I removed the shims, primary pressure hovered around 65 PSI.

I just spoke with somebody at the company where the PO purchased the refurbed WUR. They said they will straight up exchange my core with a rebuilt unit for $220. Apparently they receive and rebuild DeLorean parts from all over the country (US). By description they think my WUR is plugged or toast.

I should have stated this earlier but I didn't think about it until now: On cold mornings I have to wait a few minutes for the engine to warm up before I can take it for a drive. I chalked this up as being a toasted heater element inside the WUR because the car ran fine otherwise. Perhaps the WUR was/is on it's way out, or already dead?

[Ron]

If we're talking about the same o-ring then I believe it is the o-ring at the end of the pressure regulator assembly (circled below) which is responsible for sealing off the flow when the engine is turned off.
pressure_regulator.jpg

Not that one. Tyhat one is one of the two that comes in the kit you linked to (#1 in the discussion post 52). It seems a third one marked with a "?" in post 52 and inside the section marked with an arrow in your pic below just isn't included in the kit. It's only job is to "fully seal off the control-pressure circuit with absolute certainty when the engine has been switched off " as in post 59, so it should be in the kit, imho.
Image1.jpg

EDIT:
Image3.jpg

[Ron]

After I removed the shims, primary pressure hovered around 65 PSI.

I just spoke with somebody at the company where the PO purchased the refurbed WUR. They said they will straight up exchange my core with a rebuilt unit for $220. Apparently they receive and rebuild DeLorean parts from all over the country (US). By description they think my WUR is plugged or toast.

I should have stated this earlier but I didn't think about it until now: On cold mornings I have to wait a few minutes for the engine to warm up before I can take it for a drive. I chalked this up as being a toasted heater element inside the WUR because the car ran fine otherwise. Perhaps the WUR was/is on it's way out, or already dead?

Did the control pressure go to 65 as well?

If it was blocked off, letting it warm up wouldn't allow it to start running in a reasonable manner at all.

[bytes311]

Did the control pressure go to 65 as well?

If it was blocked off, letting it warm up wouldn't allow it to start running in a reasonable manner at all.

No, the control pressure stayed around 47 PSI. It's only when I add additional shims does the control pressure increase to about the same as primary pressure.

[Ron]

Please let me explain it another way:
If the WUR or its return or the FD port they go to is blocked, the control pressure will match the primary pressure, absotively posilutely!

[bytes311]

Please let me explain it another way:
If the WUR or its return or the FD port they go to is blocked, the control pressure will match the primary pressure, absotively posilutely!

That's what I don't quite understand, and please forgive my ignorance.

It acts like there is a blockage when I add shims, but otherwise without additional shims it maintains 47 PSI control and 65 PSI primary, albeit lower than spec. So the problem could be blockage in the FD or the WUR or both? If I disconnect the return line to the fuel pump I should see a good flow of fuel, correct?

[Ron]

That's what I don't quite understand, and please forgive my ignorance.

It acts like there is a blockage when I add shims, but otherwise without additional shims it maintains 47 PSI control and 65 PSI primary, albeit lower than spec. So the problem could be blockage in the FD or the WUR or both? If I disconnect the return line to the fuel pump I should see a good flow of fuel, correct?

Sorry...I didn't mean to imply anything like that! -- It seemed like you were about to drop some bucks w/o trying the test(s)...

Yes and Yes! As I said before, the WUR dumps primary pressure to create control pressure. If it can't dump the fuel because of a blockage nothing changes and they will always match.

Restricting only when it goes over 65 is odd! So, since you also started seeing trash, I'd go back to cleaning it out from the fuel filter on then trying the test. If it passes, start from scratch with the gauges.

EDIT:
To be clear- I should have said, "Blocking" (total restriction), instead of, "Restricting only...."