gbgastowers

I have several working WUR's and I'm using the one that has these numbers:
COLD CONTROL=19 PSI
WARM CONTROL=44 PSI
SYSTEM = 68 PSI

and it holds pressure when shut down for 20 min.

I am working on trying to get the system up to 75 per Dennis.

gbgastowers

This is the fuel distributor I have- I just don't know how to adjust it yet.http://928motorsports.com/parts/cisdistributor.php

checkmate1996

Ok, good. IIRC, the warm control is the most important along with system pressure. Since adjusting the WUR is not an exact science, I ended going the 'adjustable' route. By that, I modified the wur with the bolt on top of and could adjust the the fuel pressure on the fly using the gauges. I believe there is a write up on how to on this forum and pelican...

gbgastowers

Yeah- I finally figured out how to adjust one once I learned enough about how it works. It is so confusing and I about burned out my brain in the process. I hope I haven't forgot all that crap yet.

dogleg

[QUOTE=gbgastowers;8569634]It's not responding to that now.

are you saying that playing with the CO + IDLE CONTROL adjustments as its idling at the moment is making no difference to idle speed whatsoever ?

gbgastowers

[QUOTE=dogleg;8570451]CO(air/fuel mix screw) still functions but is not making much difference with the engine running. Idle screw on the front of the throttle body is not causing any change to happen now. This is all in the past few days since I started trying to dial back individual injector flow from the FD head. They both worked fine before then. Car is not happy with my changes so I am trying to dial it in today. I just have no guidelines to go by so it's a lot of trial and error(mostly error).

gbgastowers

I think it's fixed. I am going to take it for a test drive and I'll report back. The major problem I had been having in the past couple of days with the high idle and the idle and A/F mix not being able to adjust was caused by.... I had jerked the cruise cable back accidentally and it was pulling on the butterfly and opening the throttle. As soon as I figured that out everything returned back to normal. I have opened up the individual injector line adjusters at the FD pretty much all the way and have the in spec WUR on. I am gonna go see how she runs.

Landseer

Fingers crossed for you on this.
You have worked very, very diligently for over a year.
Epic rescue story.
Good luck, be safe.

dogleg

i have everything crossed for you.this car owes you a break,report back, with a video would be great.

gbgastowers

Well- It's better but still not right. It does not miss for the first time since it's been running. Very smooth. The take off is good at initial acceleration but when I mash the gas on in it bogs down and sometimes backfires. I will look at the plugs and see what's happening but really the only way I can go on the adjusting of the injectors is lowering the flow as they are pretty much maxed out now. I messed with the A/F mixture about every mile and it's tuned there as best as can be achieved in it's current state of tune. I PM'd Carl about this because he uses this model of fuel distributor but he hasn't responded. Dennis thinks my system pressure is too low at 68 psi so I am trying to get that up. I think I will order a new pressure valve since I don't have any shims to add to mine to try and increase the pressure.

dogleg

now that it running halfway right i would get a strobe onto it and check your ignition timing it supposed to be set at 3k IIRC but a rough setting of 6 degrees before tdc at 700 rpms would have it tuned close enough to be sure this isnt adding to your problems.

gbgastowers

today I adjusted the flow evenly to all injectors and on a couple the 3 mm allen(indiv. adjustment screw) is screwed all the way clockwise(all the way in). At this point it runs a revs smoothly if I press the air plate down but if I drive it it stumbles as soon as I accelerate.
My pressures are:
COLD CONTROL=19 PSI
WARM CONTROL=44 PSI
SYSTEM = 68 PSI

Maybe the control is too high..

Dennis wrote this "IIRC 4 bar (60 psi) is too high for injector pressure and will flood the engine. Try turning them down to 45 psi. The injector pressure should be equal to the system pressure, minus the control pressure, as adjusted by the position of the air sensor plate. Don't have the charts here at work so going from memory."

Or maybe the system pressure is too low

What do you think? Thanks- Gunar

http://www.youtube.com/watch?v=kq5wj...etailpage#t=4s

Dennis Wilson

From the WSM (pages 25-6g and h) your system pressure should be 5.2 to 5.8 bar ( app 75 to 80 psi) and your control pressure should be 2.8 to 3.2 (warm) with the vacuum port disconnected and 3.4 to 3.8 bar with vacuum connected and pulling 250-450 mmhg. If you tested your control pressure with a non-running engine or the vacuum port disconnected it appears to be OK. Your system pressure is too low. The injector opening pressures are 3.0 to 4.1 bar (45 to 60 psi). Just make sure they are all equal.

Recommend you back off the A/F adjustment until the system pressure is adjusted.

Dennis

atb

Isn't this a classic "too lean" condition? Sounds like you're on the right track if you're looking for more fuel pressure.

Glenn Evans

The injector pressure is NOT the system pressure minus the control pressure; it is about 0.1 bar below system pressure. The only relevance of the injector opening pressure is that it has to be below this pressure. The fuel distributor is designed to keep this pressure drop (the 0.1 bar) constant, regardless of the deflection of the control plunger, which meters the flow rate of fuel to the injectors.

You are messing about unproductively until you correct the system pressure. I call the K-Jetronic a hydraulic fuel injection system, rather than mechanical. It requires a known fuel flow rate (delivered by the fuel pump) at within-tolerance system pressure (as controlled by the system pressure regulator in the fuel distributor) to produce the correct pressures and flow rates within the system.

The cold control pressure will vary with ambient temperature (logically, more enrichment will be required when the ambient temp is lower, so the cold control pressure had to be lower, allowing the control plunger to rise higher and deliver a higher flow rate). At what temperature did you measure your control pressure? Your cold control pressure is at the upper limit (19 psi = 1.3 bar; spec is 1.1+/-0.2 bar or 16.0 +/- 2.9psi) at an ambient temperature of 20 degrees C (68 deg F) and without vacuum. The warm control pressure (44psi = 3.0 bar) is on spec (3.0+/-0.2 bar = 43.5+/-2.9psi without vacuum).

The lower than spec system pressure, with correct control pressures, will produce a lower flow rate to the injectors ie your engine will be tending to run lean (hence the backfire through the intake when you open the throttle).

Surely there must be a fuel injection specialist somewhere who will have a variety of shims for the system pressure regulator. They are just little washers, after all. You should use the proper Bosch ones as a Walmart special may corrode in gasoline. Porsche, Mercedes, BMW, Volvo and Saab used K-Jetronic from about 1974 to 1984, so parts should not be that hard to get.