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

[bytes311]

My return hose between the FD and the hard line to the tank was kinked pretty bad. I retested and Control Pressure stayed around 47 PSI, even with the additional shims in place.

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My question now is, how do I separate this fitting from the hard line? It won't budge.

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If I can't remove it, could I pick up a fuel rated hose and some clamps and call it good? I have DPI's return line I would otherwise like to use, but if I can't get that fitting off...

[Ron]

Ah! That looks like the culprit.
I'm not familiar with the DPI line. Can you post a pic?

[bytes311]

Ah! That looks like the culprit.
I'm not familiar with the DPI line. Can you post a pic?

That had to be the issue all along. Especially now that I can shim the FD and it not affect the Control Pressure. I certainly appreciate all of your help, Ron. I really do.

This is DPI's return hose. It looks like it threads into the hard line, but I can't get the original fitting off. This is the low pressure side, right? So theoretically I could put a fuel rated rubber hose between the FD and the hard line using the original fittings?

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[Ron]

Not sure, but it looks like the DPI would work as is, just doesn't have a bent pipe on the end?? I.E. remove everything from the FD on, including the bent pipe portion??

It is the "low pressure" side, BUT you need to use high pressure rated hose because regular fuel rated hose 's pressure rate is too low for the system. ...If you ever get a restriction down stream on the way to the tank, regular fuel rated hose will burst!

Sorry I didn't answer right back...A man wanted to buy my Silverado...

[Delorean Industries]

Sometimes it can be a fight to remove the factory fitting from the compression sleeve as pictured. This will release if you carefully hold the back side of sleeve (where it is exposed) and rotate the fitting.

If you have any questions on the orientation of the lines at the distributor (double banjo fitting) reference pictures are available on the product page. If you have any other questions just let us know.

https://deloreanindustries.com/1-bra...mall-line-set/

[bytes311]

Sometimes it can be a fight to remove the factory fitting from the compression sleeve as pictured. This will release if you carefully hold the back side of sleeve (where it is exposed) and rotate the fitting.

If you have any questions on the orientation of the lines at the distributor (double banjo fitting) reference pictures are available on the product page. If you have any other questions just let us know.

https://deloreanindustries.com/1-bra...mall-line-set/

The fitting came off after doing exactly what you suggested. Thanks! The new braided hose is now installed.

Control Pressure was still acting weird last night. As soon as I blipped the throttle, it shot up from 47 PSI to 70 PSI and remained there. I confirmed the return line is completely free from blockage between the FD to the tank. I also remembered I added an extra shim to the PPR, so I removed it. Now Control Pressure is a constant 47 PSI.

I wouldn't think so. If residual pressure from the WUR's return line can't get past the PPR's piston, it can't go anywhere, i.e., cause a rich condition.

I think the extra shim put too much tension on the spring, enough so that the piston couldn't move to release residual pressure.

[Ron]

Control Pressure was still acting weird last night. As soon as I blipped the throttle, it shot up from 47 PSI to 70 PSI and remained there. I confirmed the return line is completely free from blockage between the FD to the tank. I also remembered I added an extra shim to the PPR, so I removed it. Now Control Pressure is a constant 47 PSI.

What did the Primary Pressure wind up being in the end?
If the Primary Pressure was ~70 PSI when the Control Pressure shot up to 70 PSI, you had a restriction/blockage. The 'rule' about them matching always applies -- Even if you added 2 or 3 extra shims, the Primary Pressure would skyrocket, but the control pressure should basically remain normal (49-55 PSI, warm).
I'd guess you disturbed some trash somehow while removing the extra shim...

I wouldn't think so. If residual pressure from the WUR's return line can't get past the PPR's piston, it can't go anywhere, i.e., cause a rich condition.

I think the extra shim put too much tension on the spring, enough so that the piston couldn't move to release residual pressure.

Ignore that reply -- It was about a different o-ring than the one next to the shims and COLD starts.

...The number of shims determine how much System (Pump) Pressure is released to obtain Primary Pressure (and the WUR releases Primary Pressure to obtain Control Pressure).

[bytes311]

What did the Primary Pressure wind up being in the end?
If the Primary Pressure was ~70 PSI when the Control Pressure shot up to 70 PSI, you had a restriction/blockage. The 'rule' about them matching always applies -- Even if you added 2 or 3 extra shims, the Primary Pressure would skyrocket, but the control pressure should basically remain normal (49-55 PSI, warm).
I'd guess you disturbed some trash somehow while removing the extra shim...

PP and CP became the same after I blipped the throttle. I'm just not sure what it could be at this point other than there being a restriction inside the FD itself, or something related to the PPR. My WUR/CPR unit tested OK. The flow of fuel returning to the tank looks good. The jerrycan between the FD and hard line collected approx. a gallon worth of fuel in a minute and a half. Control Pressure is not affected at all if I leave the PPR alone with its original shim in place.

[Ron]

What is the CP and PP now?

[bytes311]

What is the CP and PP now?

CP is 47 PSI and PP is 67 PSI.