CIS assistance needed

[jimbeaux911]

OK so I am installing a 3.0L into this car for the first time. I cleaned out the gastank, installed a new fuel pump, blew out the gas lines ( the return was plugged) added a new fuel filter, blew out all the fuel lines and connectors, installed a rebuilt fuel distrinibutor, and then another rebuilt fuel distributor, installed a new pressure regulator into the fuel distributor, installed a new cold start valve. All new injectors, plugs.

I am having issues with too much pressure from the the fuel distributor down to the WUR. its reading 50 psi at idle and I cant keep the car running. I checked the pressure in front of the WUR and after the WUR, and it is the same with it backed all the way out, so the WUR is not clogged. this pressure should be opeining the main fuel presssure regulator and sending fuel back to the tank, thus lowering my pressure. but still I have 50 psi measured coming out the top of hte Fuel Distributor going to the WUR.

ANY help is apprecited as I have done EVERYTHING I can think of. I have taken ALL the lines off today and blew air through the fuel injectors, fittings, hoses, fuel filters, etc. the return line is clear as I can blow air through and here it going into the tank. Also took it off and blew air through it as well.

checed for spark and timing is good. Any suggestionns? anyone experience this before?

Jim

[boyt911sc]

Jim,

Let's start from the beginning so I could get a good feel of what you are doing with your CIS. On a cold engine measure the cold control, warm, and system pressures (use psi. for me). You don't need to unplug the electrical connection to the WUR. Test run the FP with the pressure gauge correctly installed. The instant the FP starts to run, use this initial pressure reading as your CCP. Allow the FP to run no more than 5 mins. and make sure you have a fully charged battery.

Record the control fuel pressures versus time (0, 1, 2, 3, and 4 mins.). The control fuel pressure may or not reached the WCP after 4 mins. Observe the gauge pressure reading is steady and not rising anymore. Close the shut off valve and measure the system pressure (psi.). Stop after 5 minutes.

Might as well include the Bosch number on your WUR and FD. The tests will show if your WUR and FD are in good working condition. BTW, what year is your 3.0 liter engine? Keep us posted.

Tony

[jimbeaux911]

Thanks Tony!

Its a 79 engine, no lzmbda box to worry about. I can run the tests as described tomorrow.and will provide data. Initially my system pressure was way high, until i unclogged the return line. now it seems to be around 60 psi with the valve to the WUR closed, but when open it doesnt seem to drop much if memory serves me. I have the WUR backed all the way out, and still cannot get the pressure to drop. not sure I can keep it running for five minutes . LOL

Looking forward to figuring this out.

Jim

[prschmn]

Do what boyt says--but besides that--pressure downstream of the WUR should
not be anything like that high. Are you sure the return from the WUR is not restricted?
System pressure is more like 70 PSI so it isn't the 50 thats killing you.

[jimbeaux911]

I agree Mark. I was happy to get 50 psi, esp since the first go round I was at 130 psi, turned out hte return line to tank was clogged.

I took the return line from the WUR off today, and blew air thru it, no clogs. what kind of pressure should one see downstream from the WUR? I understood it sends pressure up to the fuel distrib to 'control' the system pressure, so one needs high enough pressure to push the central plunger down and lean out the mix as the car warms up. this is all new to me, but it does seem fairly strainght forward, now that I have had it apart a few times. I feel like I am close, but just too far away at the same time.

Thanks for the comments. please keep em coming. my frustration is already going down.

[wakeupct]

Good luck. I'll be keeping an eye on this thread as I will be at this point soon.

Pete

[prschmn]

Try thinking of it this way. The fuel distributor is full of system pressure. The WUR
is a bleeder to lower that above the metering piston to allow more when cold and less when hot.
50 is in the ballpark for warm control pressure but needs to be less cold for "choke" effect.

[boyt911sc]

Originally Posted by jimbeaux911

Thanks Tony!

Its a 79 engine, no lzmbda box to worry about. I can run the tests as described tomorrow.and will provide data. Initially my system pressure was way high, until i unclogged the return line. now it seems to be around 60 psi with the valve to the WUR closed, but when open it doesnt seem to drop much if memory serves me. I have the WUR backed all the way out, and still cannot get the pressure to drop. not sure I can keep it running for five minutes . LOL

Looking forward to figuring this out.

Jim

Jim,

We are just doing a fuel pressure test. No need to run the engine. Are you familiar how to manually test run the FP? I thought you said you have a newly rebuilt FD? Your system pressure is too low. Set it to 72 psi.

Could you post the Bosch ID number for the WUR and FD? Do you have the correct WUR and FD? Keep us posted.

Tony

[boyt911sc]

Jim,

Your WUR and FD are your problems. Both of them are not giving you right fuel pressures. I will be very surprised if you could make this engine to idle and run. Who rebuilt the FD? You don't need a running engine to test your WUR and FD. All you need is a set of pressure gauge and a running FP. Get all the related fuel pressure data before even attempting to run the engine.

This is what I've been doing the last two days testing and calibrating WUR and FD.



Tony

[jimbeaux911]

getting ready to head to the shop and work on the fuel issue. HOw does one 'set the pressure" as you suggest.

[ossiblue]

I agree with Tony and suggest you follow the procedures, above^^.

Your OP was a little confusing to me when you wrote, " I checked the pressure in front of the WUR and after the WUR, and it is the same with it backed all the way out..." It sounds like you have an adjustable WUR, is that correct? If so, what do you mean by having it "backed out all the way?" I suspect you adjusted the cold control arm upward (by backing out the adjustment screw and raising he control arm pin), thus raising cold control pressure to the maximum level--the warm pressure setting. To lower the cold control pressure, the pin (or adjustment screw/bolt) needs to be moved down into the WUR body.

If I have misunderstood your post, I'm sorry, but your problem would be a logical result of what I have described. If you follow Tony's advice, your settings will be in spec and your engine should run.

[Paulporsche]

LJ, or is he backing out the mixture adjusting screw or the idle setting screw, thinking he is working on the FP?

Jimbeaux, you can adjust the fuel pressure via shims that go into the top portion of the fuel distributor.

Check the enclosed chart for control pressures for the WUR, which vary by temperature. Fuel pressure is a constant @ 70-75 PSI as others have stated.

[Paulporsche]

.

[Paulporsche]

Fuel adjusting shims are number 3.

[jimbeaux911]

OK so I am not fooling with the idle control mix.

WUR # is 0 438 140

FD # is 279973 729

THe system holds pressure of 30 psi with FP off

With the ignigition off, and fuel pump on, the pressure rises quickly to 105 PSI.
( I think my lower reading yesterday were due to air inthe lines).

for the full five minutes, the pressure sat at 105 PSI.

seems like there is a blockage somewhere? I did have a blocakge in the return line, blew it out a few times, and you can see the gas running into the tank now with high flow rate, so I beleive the return line to be clear.

Any suggestions?

Jim

[jimbeaux911]

currently no shims in, and pressure is at 105 psi

[ossiblue]

Originally Posted by jimbeaux911

OK so I am not fooling with the idle control mix.

WUR # is 0 438 140

FD # is 279973 729

THe system holds pressure of 30 psi with FP off

With the ignigition off, and fuel pump on, the pressure rises quickly to 105 PSI.
( I think my lower reading yesterday were due to air inthe lines).

for the full five minutes, the pressure sat at 105 PSI.

seems like there is a blockage somewhere? I did have a blocakge in the return line, blew it out a few times, and you can see the gas running into the tank now with high flow rate, so I beleive the return line to be clear.

Any suggestions?

Jim

Okay, please clarify.

Fuel pressure rose to 105 psi and held that for the full five minutes. Did you open the valve on the gauge set during those five minutes--that was not clear. If you did, then the reading made no change for the cold control pressure, correct? You said you believe the return line is open, but you haven't answered my previous question, what did you mean by the WUR was backed off? What exactly did you do to the WUR in your original post? A WUR with the cold control arm set too high will display symptoms just like you describe as the pressure regulating diaphragm is pressed solidly upward allowing no bleed off of pressure. Gas is running back into the tank, as you observed, so that means the fuel is flowing through the WUR, but the pressure is not being reduced which points to a problem inside the WUR--most likely the diaphragm is too high or is, somehow, stuck to the top of the chamber.

[jimbeaux911]

Originally Posted by ossiblue

Okay, please clarify.

Fuel pressure rose to 105 psi and held that for the full five minutes. Did you open the valve on the gauge set during those five minutes--that was not clear. If you did, then the reading made no change for the cold control pressure, correct? You said you believe the return line is open, but you haven't answered my previous question, what did you mean by the WUR was backed off? What exactly did you do to the WUR in your original post? A WUR with the cold control arm set too high will display symptoms just like you describe as the pressure regulating diaphr agm is pressed solidly upward allowing no bleed off of pressure. Gas is running back into the tank, as you observed, so that means the fuel is flowing through the WUR, but the pressure is not being reduced which points to a problem inside the WUR--most likely the diaphragm is too high or is, somehow, stuck to the top of the chamber.

Correct, even with the valve open to the WUR loop, the pressure held at 105 psi.
I have messed with the WUR to the point where I pull it up then tap it down to adjust hte pressure, I had the cylinder completly removed from the unit at one point, and if I press on the bottom diaphram the pressure INCREASES. Running the FP with the WUR cylinder removed from the unit still results in 105 psi. In or out it does not matter.

[ossiblue]

Originally Posted by jimbeaux911

Correct, even with the valve open to the WUR loop, the pressure held at 105 psi.
I have messed with the WUR to the point where I pull it up then tap it down to adjust hte pressure, I had the cylinder completly removed from the unit at one point, and if I press on the bottom diaphram the pressure INCREASES. Running the FP with the WUR cylinder removed from the unit still results in 105 psi. In or out it does not matter.

Now I'm really confused.

Do me a favor and look at the drawing, below, and tell us which parts you pulled up and down, and which was the cylinder that you completely removed.



If the parts you dealt with are not labeled, just describe them according to the diagram. I'm having a hard time visualizing what you've been manipulating.

[jimbeaux911]

here is a pic of what my WUR looks like. THe circle on top is the cylinder that I was tapping upwards as part of the adjustment process, and it easily comes completely out, exposing the diaphram on the bottom of the cylinder.