SeanR

Oh, another tool you need is Rogers CIS Fuel Pressure test kit.

Doug_B_928

That's what I'm using

Doug_B_928

I had ordered a fuel pump check valve on spec. (don't have any other parts, like cold start injector). It comes with three washers. Two are thin and larger in diameter, one is thicker and smaller in diameter. It's hard to tell from the WSM, but based on my old one the thicker one goes on the pump/short side of the valve. The problem is that the washer does not appear to be big enough in diameter to go over the valve. I've attached a pic of the old one with washer and new one with washer. Did they give me the wrong washer or is there some trick to getting it on (I recognize that I am seriously sleep deprived and there's probably an obvious answer to this)?

Jadz928

Thanks for the tip, Sean. Could we talk about this sometime? Would like to have a first-hand understanding about it. Thanks!

Doug,
Unless I missed it... what year 928 CIS are you working with?

Something to note, depend on you MY... the early cars (78-79, IIRC) have a built-in check valve in the FP. Before going thru replacing, check to see if you need it.

After you pressurize the system, do you see a quick pressure drop on the guage? At that point car you'll hear fuel draining back into the tank (thru the fuel pump or top of the fuel tank).

The built-in FP valve has a long hex-shaped barrel on the end, and inside you can see the spring.

Report back.

Doug_B_928

I didn't notice a drop with system pressurized, but the rest pressure wouldn't hold. Since it's a cheap part and I had it I thought I'd give it a try to see if it makes a difference. My car is a 79. Below is a pic of the FP. I think it also has an in-tank pump which I was planning on replacing with a strainer eventually. I"m still not sure how that washer is supposed to fit. Should I re-use the old one?

Jadz928

That is what I meant, the rest pressure drop. Reads like you are on the right track. That FP pic does not have a builtin check valve.

Doug_B_928

Thanks, Jim. Any thoughts on the washer situation?

Jadz928

One for the check valve, then 1 on each side of the banjo.

Doug_B_928

Yeah, only problem is one for the check valve is too small in diameter to fit over the valve. Fuel was dripping so I used the old washer and put the pump back on. No leaky so hopefully it will be good. I'll keep my eye on it.

Just re-did the pressure tests with essentially the same result. Seems like it could be leaky injectors and/or cold start injector (and/or WUR)

LT Texan

your new check valve came with crush washers that didn't fit?

Doug_B_928

The thicker one that goes next to the pump definitely would not fit.

jtrygstad

Just for what its worth, this site has lots of CIS / K-Jetronic components and parts.

http://www.specialtauto.com/delorean...injection.html

Don't let the Delorean thing fool you - a gold mine of CIS parts and service.

Two things from here that really helped me out with my 80 Euro was the O-ring kit for the primary pressure regulator ($3.50) on the fuel distributor and the rebuilt WUR (previous owner had stuck a Mercedes 350SEL on mine! Took me forever to figure that one out.)

Jadz928

Do you hear any of you injectors squirting? Very audible.

Could your AF screw be set to rich, thus dropping in too much fuel?

If you screw the AF to far CCW, you can hear all injectors.

Just spitballin'...

tailpipe

its probably dirty injectors that are leaking but it could also be a leaking cold start injector, just be carefull not to break the plastic housing when removing it. I have also had a car that was leaking fuel through the accumulator and through the carbon canister and into the intake that was fun to hunt down, that is only possible if your accumulator has the vent tube on top. All your injectors can be cleaned just take them to a diesel service shop they can clean and test them for you

Doug_B_928

@ jtrygstad--thanks for the sites!

@ Jim--I didn't notice any sounds from the injectors, but I'll double check.

@ tailpipe--thanks for the tip about taking the injectors to a diesel shop, wouldn't have know that.