When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
On your picture , I can see one side of connecting of the frequency valve ( return to tank of the FD ) but where is connecting the other side ?
The pressure you give ( 40 to 45 Psi ) is taken where ? Direct on the WUR ? Because it's the good pressure for the WUR when hot and without vacuum ...
Where you connect your manometer ?
Me , one on teh cold start valve for the pressure system and another on the entry of the WUR , see picture :
Here , it's rest pressure after 10 minutes .
I would defeat (as in remove) the aftermarket frequency valve and any of the lines/hoses to and from that injector. Go back to factory configuration.
Once that variable is removed, you should be able to quickly determine why it won't start and run.
Once the car is running and tuned, if you want to put those aftermarket pieces back on....that's up to you.
The car is a 82 row gray market car m28-12 with a 4.7 atm
the car looks like it came with added features like leather stitched dash and leather wheel and LSD rear.
I took a good look at the wur and it’s definitely a 068 part number. The car felt like it was having return line issues so I took off the return line to check for any blockage and took out the FPR and cleaned and reinstalled. I also took off the large metal line that has the bango with the screen in it and found a nice amount of dirt in the line. I took the piece out that has the screen in it and clean that and flushed the line and the inlet to the FD. I put it all together and the car fired up and ran but i think it’s dumping too much fuel in the cylinder I think because it would run and rev but after a min or two it stalls and when I go to start it the engine won’t turn over and feel like its vapor locked. After a few minutes it would start and do the same thing. I’m pretty sure the line with crap in it was the issue. Tomorrow I’m going to hook up the gauge and see what I get at cold start and go off the sheet that you posted.
im pretty sure it’s dumping to much fuel because the exhaust smelled like in unburned fuel. What controls the amount of fuel going in the wur ?
the line all the way on the left was the line with the dirt in it
Last edited by 82EUROATM; 05-14-2020 at 11:36 PM.
Reason: Adding info
In my limited experience, the unburned fuel smell in the exhaust is much more often related to "too lean" than to "too rich". The engine is amazingly tolerant of over-rich conditions, but misfires and shuts down quickly as you take it lean.
The flow through the WUR is related to system pressure on one side, and the control pressure the WUR is trying to maintain by bleeding fuel out the to the tank return. WUR pressure is temperature-sensitive to coolant temp, plus has a heater to speed the control pressure increase on cold-cold starts. The control pressure setpoint is biased by intake vacuum to assist cold starting and higher-load transitions.
I have gotten a little further today.its definitely running rich to the point where the plugs where totally covered in black sut. I cleaned the plugs in my spark plug cleaner and put them back in and the car ran for a few minutes enough to get to operating temp. It was idling up and down looking for a happy place but the plugs fouled out again.im going to take out that injector because I think it’s causeing problems..
You'll want to find the correct original WUR i you decide to disable the modulating valve. To make that system work, WUR needs to let control pressure go lower than the original unit, so the injector can modulate from the lower/richer control pressure through normal range.
When the engine is running, you should be able to easily hear and feel that modulating valve buzzing. You can use an oscilloscope to watch the duty cycle of the valve. In a properly set up system, that duty cycle should be cycling around 50% at Lambda = 1.
Yes you are correct when the car is running I hear the injector buzzing but don’t have the machine to get any readings. Would the system work Without the injector if I ran a direct line without the injector. I believe I have a better chance to get it running if I bypass it and maybe go back later and put it back when I get the tool. Is there anyway to set the FD to a setting where it’s close to where it should be. What I did was with the key on and the pump on I backed the screw all the way out and turned it clockwise till I herd the injectors come on and left it there. I’m not sure why but when I got the car running yesterday I had the gauge on and I was getting no system pressure readings while the car was running.
If you decide to bypass it, find and install the correct WUR at the same time.
If you have legacy/vintage/antique tools in your collection, you might have a "dwell meter" that dates to the times when ignition was by points-and-condenser triggers. That "dwell" reading can be translated into "duty cycle". Some modern DMM's also include a duty-cycle reading for use with PWM-controlled devices in a modern car.
If you tweaked or otherwise changed the adjustments on the tan box, you'll find yourself balancing the control pressure with those adjustments again so that 50% duty cycle does in fact give you the correct CO percentage.
Thirty-plus years ago I designed and built one of those controllers so I could tune the fuel on my CIS Saab Turbo. Mine had way more than three adjustments, and it took a bit of work to get it to work well all the time. All analog stuff. I wanted 250+ horsepower from the 135 HP low-pressure turbocharged 2-liter engine. Made more than that eventually, with knock sensors, intercoolers and a bigger turbo. Fun stuff, and would have been a lot easier in digital.
I found some good literature on the ke system and according to what I read it adjusts the bottom half of the FD which sounds crazy but I see how the injector if calibrated correctly might give better fuel economy I guess.without the machine to calibrate the controller I’m pissing in the wind. I think I’m going to bypass it and see what happens with the gauge in it.
There's no "machine to calibrate the controller". You'll need to be able to get a CO reading at the header pipe (which is needed no matter if K- or KE-jet), and be able to read the duty cycle of the modulating valve.
The "bottom of the FD" gets the control pressure from the warm-up regulator to bias the mixture some. The whole metering unit consists of the airflow plate and arm, which actuate the main piston in response to airflow changes. Control pressure biases that movement, generally increasing fuel flow when the engine is cold, increasing when the manifold pressure is high (less vacuum), all done via the warm-up regulator. Since you "rebuilt" the warm-up regulator, I have to hope that you didn't try to bend the bimetal 'spring' plate inside. The position and pressure applied to the bypass valve are critical to proper function. Generally, the WUR is carefully calibrated to a very specific temperature/flow curve for each car. You can recalibrate yours back to original with a bit of plumbing and a spare pressurized fluid source. Or get the correct piece, already resealed and calibrated, from 928 International. The piece you have was quite probably set up for a lower control pressure curve, allowing the modulating valve to close some of the time to increase control pressure and lean the mixture back towards ideal. If you decide to ditch the electronics and the modulating valve, you'll need to get the correct original WUR in there if you want the engine to run anywhere close to correct. Get the replacement WUR return pipe when you get the WUR from Tom and Mark.
You MUST have the system completely clean, with all filter screens in place in the FD and WUR plumbing. The tiniest bit of crud in either will mess with pressure and flow regulation, as you have discovered. Take the time for this step, all the way through pipe-cleaners, solvent flush, compressed air, etc. Crud and rust in the plumbing is the common nightmare of reviving CIS cars.
Hey dr bob I took out the injector today and it fired up and ran for a bit and I realized that it’s not vapor lock that’s locking up the motor it’s fuel being dumped into the cylinders causing the motor to lock up. I pulled the spark plugs out and they were dripping in fuel. I put the gauge on and I got 68 psi control pressure I believe that’s with line closed when I open the line I got nothing zero psi and the motor was locked up. Why do I have no system pressure. Wur ? I know I’m probably asking a lot of dumb questions
05-14-2020, 07:11 PM
