SMTCapeCod

For the fuel dumping, ensure that the throttle plate is fully returning properly, and that the plunger in the FD is following suit. I would suspect that the injectors could be stuck open, but it seems like you're seeing dumping in multiple cylinders which makes that less likely. For the WUR...they are getting scarce. You probably already know of 928 Intl for used bits, and some of the other vendors have used or rebuilt items kicking around from time to time, or know someone that does so call around. I found that this Delorean place has some compatible rebuilt parts, if you search by the Bosch part number:
http://www.specialtauto.com/
I also used to prowl Ebay.uk and other overseas markets for used CIS parts.
I had an 83 Euro that was set up similar to yours with the hot start valve, etc, but the KE controller was already removed. Some of the same experts providing you input here, were indispensable in helping me to get mine sorted out...it took a long time and as you alluded to, a lot of new parts when multiple faults made it difficult to isolate them one at a time.

82EUROATM

I don’t think it’s the injectors they are all brand new.
the throttle plate is good and everything in the back to the front has been gone thru. I believe the frequency valve needs to be put back and go from there. Before I took it out I had control pressure and system pressure but it was dumping too much fuel and fouling the plugs out and gas going into the cylinders and in the oil. I’m on my 3rd oil change because I keep getting gas in the oil. I have no control pressure and system pressure is almost 70 psi. The return line is not returning enough fuel back to the tank. From what I read in the Ben Watson book if a car is fitted with the KE jetronics the lower part of the FD is modified to work with the frequency valve and a fuel pressure modulator on the side of the throttle body which is connected to the temp sensor. Between the frequency valve and the modulator I believe that’s what gives me control pressure according to the book. I’ve had 3 other 928 cars but they were all electronic setups. My first cis car

allan29

It's not a KE Jetronic but an "exotic" KA Jetronic calling too K Lambda like many Porsche 930 or some 924 .
Your WUR 068 is near the cold curve than the 086 / 036 and same at hot .

If you dont have the good main pressure ( 5,2 to 5,8 bar ) , all the other parts like WUR can't play the game !
This is the first thing you need to solve !

dr bob

Connect the leads of the o'scope in parallel with the two wires running to the frequency valve. The trigger voltage is going to be in the 9-12 volt range so set the gain accordingly. I don't know the normal frequency that your tan box works at, so set that scale once you start the testing. You'll need to be able to read CO upstream of the catalysts, so you can get the control pressure correct. Watching the duty cycle is a good idea to see how the controller is responding, but eventually you'll look to have the CO correct, control pressure correct, with valve duty cycle around 50%.

82EUROATM

I have 65 to 68 psi system pressure when cold but zero control pressure . I checked the fpr and opened
The FD just to make sure everything was good. I did check the the return line for flow rate and only 5 to 7 oz of fuel per 30 seconds. The issue has to be in the return line back to the tank.

82EUROATM

just so I’m sure the return line to the tank is the metal line that sit to the far left of FD and run back to the 2 main lines on the passenger side.

82EUROATM

Ok guys I e been at it for weeks now trying to get my pressures in line and can’t get any control pressure.
system pressure is good and rest pressure is good.
fuel pump flow is good and return flow is close to where it should be.
i have 55 psi system pressure cold
FD is rebuilt and wur was boiled and cleaned.
it looks like the wur is not adjusting the return flow because when I pinch the return line after the wur it goes to 55 psi which is the same as system pressure. I have gotten a lot of good advice and tried everything.
i have replaced almost everything on the car that would give me issues but I can’t get passed the wur in the system. I have 82 euro gray market car that a ke Jetronic system on the car that I took out because I couldn’t get passed that injector thing. The wur in the car is a 068 but what belongs in the car is a 086 and hard to get.

dr bob

Attached new post to existing thread. Let's try to continue the theme in this thread. Worst case would have a link to older related thread in your new thread.

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Put the Lambda valve back in, and connect everything as you originally found it. The base problem of low system pressure is somewhat solved IF the system pressure you see matches the chart for the car. Don't Run The Engine. Battery charger connected in rear, key in RUN position, fuel pump relay jumpered. Use your hand vacuum pump to get test vacuum on the WUR, but that may do nothing with the WUR not holding any control pressure. The tan Lambda controller should modulate the valve to manage cold-start control pressure. Adjust the controller with your PWM meter attached to the valve wiring. At 50% duty cycle, the control pressure should be in spec. If not close, you need to get a WUR that works. If close, you can adjust the controller to get the valve percent open time and the measured control pressure correct. Mark the position of the adjustments before you start moving anything. If you adjust something and it doesn't seem to do anything, move it back to the as-found position. Once you have the control pressure correct for cold start, only then can you crank and start, and only after you VERIFY THAT THERE IS NO FUEL IN THE CYLINDERS. Plugs come out for that check, and they need to be dry and not fuel-stinky at all.

If you don't want to or can't go through getting the Lambda valve working, your only option is finding the correct WUR for your car, and remove the lambda valve and it's plumbing completely. Then... system and control pressures need to be correct with test vacuum applied, all before you try and start the engine. Waste No Time trying to start the engine before the pressures are correct.

82EUROATM

I will give it another try with the original set up. I went over the entire system to see if I missed something but again I hit a wall with the wur. The wur is not adjusting anything so I believe this wur is setup for the frequency valve. The 086 wur I would have to buy new or used with no core because I don’t have a 086 to give back. The cheapest one I saw was 800.00 and that was used.
i will post results tomorrow and thanks for your patience I must sound like a broken record

82EUROATM

Ok I have mt3000 Snap-On machine that measures duty cycle and dwell.
I was able to get it within range with duty cycle in between 50 and a dwell stroke about 45 degrees which I believe what it calls for. I will put everything back and give it a shot. Is there anything I’m missing?


This is the machine I purchased

82EUROATM

Ok I put everything back in and set the duty cycle to about 50% it was jumping back and forth but it was close with a dwel at 45 degrees and that’s what the Ben Watson book says it should be. I have 60 psi system pressure and with 50psi control pressure and that’s with the key on and FP jumped . The injector was pulsing right about 50 psi which I believe is a little high if I’m correct.
should I try and start the car or try to get it closer to 35 psi control before I go forward

dr bob

Since you previously adjusted the settings on the Lambda box, go ahead and adjust again to get the correct control pressure. I don'y have the charts for your euro car, so you'll need to adjust to whatever those say. Changing the duty cycle will change the control pressure, but since I have no idea what controller is being used, and none of the adjustments are labelled... we are a little bit blind. Tune for the correct control pressure though.

Once system and control pressures are correct, you'll need to sniff CO in the exhaust upstream of any catalysts, and tune the adjustment on the paddle (allen screw in the top of the FD unit) to get the duty cycle back to 50%.

I like the pocket version of the tester you bought --

82EUROATM

I was able to get control pressure at 40 psi cold and system pressure at 65psi which is right on the money but it didn’t start so I turned the Allen screw 1/8 turn at a time until it finally ran and stayed running but when it warmed up I gave it some gas and it sounded good but shut off and it wouldn’t start. I had good system pressure and good control pressure when warm. The brown box has 3 adjustments
closed loop
open. Loop
enrichment adj
the closed loop is what adjusts the pressure
the open loop adjusts the cold start
enrichment screw adjusts the speed frequency in which the injector pulses.
i adjusted the closed loop setting and that’s what dials in the duty cycle. The machine that I have gives you both duty cycle and dwell degrees and same time that’s how I new I was real close.
the book says 45 degrees dwell at 50% duty cycle.
i pulled a spark plug to see if it was running rich but it was clean which means it’s running on the lean side

82EUROATM

Ok I have good news I got my psi in line from the help DR BOB and many others and it is finally running with the KE JETRONIC setup. I got my cold pressures in line and set Allan set screw to lean and kept turning it a1/8 of a turn until it stayed running. My warm pressures are good e except my control pressure is low. The book calls for 41 to 46 psi and I’m running 10 to 25 psi But it’s running good. I can’t do a sniff test from the tailpipe because the car has no exhaust past the cat. I’m guessing i have to play with the closed loop on the box to see if it goes up.
i want to thank everyone for helping me get this far and if it wasn’t for dr bob to keep pushing me I would have been at this for way longer.
You guys rock and I will forever spread what I know forward.

dr bob

Getting the control pressures lined up both hot and cold is essential, and I'm not sure how to do that with your setup. It a function of the WUR, which heats up with coolant, plus has the electric heating element to speed the transition from cold-cold start. With your WUR doing nothing, the control pressure functions fall solely on the Lambda box and its connected sensors. A new oxy sensor would be a good idea since you've drowned yours. , so you can tune the closed-loop to follow the actual exhaust mixture. Your low control pressures now mean it's running excessively rich. When you can get a good sample for CO ahead of the cats, you'll get to tune the low-speed airflow with that Allen screw so it will start and idle without burning down the catalysts. Too rich causes the catalysts to run excessively hot, too often resulting in 928 carbeques. Don't drive very far with those pressures so low.

There are a few wideband oxy sensor systems that let you watch the mixture vi the CO at the sensor. Since you are fitting more exhaust, have your exhaust shop weld another sensor bung into the piping ahead of the catalysts, where you can fit the new sensor. Don't try and use the narrow-band output from a wide-band analyzer; there's enough latency in the translation to make the controller hunt, and making tuning all but impossible. Others here will recommend a sensor. I think the Innovate units are popular. My later car has nothing easily adjustable short of adding new PROMS and SharkTuning, so no need for more analytics right now for me.

Keep us "in the loop" as you progress with the injection on the car. If your experience is anything close to our typical member, this little injection thing is just the dipping-your-toes-in to the pool of 928 experiences.