Thank you for great demonstration. I have one question regarding the vacuum part of the WUR. I was setting up my WUR after rebuild these days, I was quite puzzled at the beginning but finally I got the point how to adjust the pressures correctly but I was not able to get vacuum working while engine was running, later on after massive investigation I discovered that smaller connection hose coming out of the hose that connects ISV and fifth injector was blind from the production so it was no vacuum comming to this small hose. Anyway I did not understand whats the purpose of this vacuum as I suppose that the vacuum is being produced during whole engine runtime and I cannot imagine in which situation can be this vacuum system used for enrichment of the fuel mixture and how it should work
Thanks, the vacuum is applied to the diaphragm in the WUR when the throttle is closed and partially open, when the throttle is opened there is a lean fueling situation before the extra fuel is delivered to the injectors, to counteract this once vacuum is lost (when the throttle is opened) is reduces control pressure momentarily thus allowing a touch more fuel to overcome the lean patch
That is amazing, but I did not notice any pressure drop during my tests, I suspect that the vacuum lost is not happening in my case, can you tell me which element should cause this behaviour (vacuum lost=pressure drop)? Thanks
@@GreyGooseRestorations I am not sure if I understand. When vacuum line is disconnected from WUR, pressure drops by around 10psi. I have set the control pressure to around 50-51psi with vacuum line connected, is that correct? Thank you
Yes definitely set all control pressure with pipe in tact, if the pressure is changing when running and the pipe is taken off/clamped then that indicates the vacuum portion is functional
I have watched your video on TH-cam and wondered if I could have a few pointers before purchasing the incorrect parts. I am trying to help out a friend who purchased a non running V6 Volvo from the 80's which has K Jetronic fuel injection. It initially did not start but he found that the in tank fuel pump pipe had rotted away so no fuel was getting to the distributor. In trying to locate the fault he took apart the fuel distributor and could not see any blockages. I then went round and carried out some fuel pressure tests as it starts but once it has warmed up a bit runs very, very rich with thick black smoke from the exhaust. The readings are System Pressure 5.4 Bar (spec 5.5) Control Pressure 2.3 Bar (spec 3-3.4) so the control pressure is low. Would the WUR cause this as I thought that when they fail they usually fail lean ?
WURs normally fail casuing high control pressure. Low control pressure would cause rich running, was the metering head put back together and set right as it could be at fault sending more fuel to one or more of the injectors
@@GreyGooseRestorations I will have to check, but it seems to run without being too rich when cold, it is only once it begins to warm up that it becomes increasingly rich. Thanks by they way for your response
Great video! I have a WUR without vacuum. It also doesn't have an adjusting screw. How would you suggest I adjust the control pressure? Also, can the screen filter that is in the inlet banjo bolt hole be removed for proper cleaning purposes?
Hi, to adjust that type either modify if like shown with the extra threaded parts to adjust cold and warm pressures. Its near impossible to remove that flat filter without causing damage unfortunately
The vacuum chamber needs manifold vacuum (after the throttle body) the allen key behind the brass cover will have an effect on all workings eg cold, warm both with and without vaccuum applied depending how well the wur is or how it's been set previously
@@GreyGooseRestorations Thank you for responding , I appreciate it . K jet is a brilliant system but it’s a bit a bit confusing I’ll admit . I’ve one more question if you’re up for it . You might laugh at this but I’m running a Mercedes 450 SLC with a rear mounted turbo . I’ve got great warm performance but if I shut it off for even five minutes it starts up chugging and blowing black smoke / stalling . I have an afr ratio sensor / guage installed which has been helpful . I’ve set up the warm mixture with the ( tap the steel cylinder into the wur housing ) method because I didn’t know any better . I’m wondering if my screw at the bottom is adjusted too far out possibly . Thank you for your time . I’ll have to send a few pics / vids of this beast I’ve created , you’ll no doubt get a kick out of it ..
I just recently discovered that there is no power coming to the ISV cable (when ignition on), what would you suggest looking at first? Is there a relay designated for the ISV? Or what else could it be that disrupts ISV power? It seems to have no cut cable or any visual issue in engine bay.
Love the cut aways man, definitely cool to see! I am currently working on an 87 420sel and after rebuilding the fuel distributor I’m not getting any fuel to the injectors but have good pressure at the supply line and a new screen filter at that line too. I’m about to start taking it apart again, what would you think might cause this issue? I’m thinking I placed the diaphragm gasket wrong or something
@@GreyGooseRestorations I tried to start the car with and without touching the pedal to open and close the air flap and in both circumstances I had only 1 injector line that had a little fuel come out but nothing close to the pressure required to start and it was only 1
@@GreyGooseRestorations I’ll try and turn the c02 adjustment when I get home, the car ran great when parked and that adjustment hasn’t been touched though so I’m leaning towards the metering head. Even if the c02 adjustment was off though wouldn’t at least some gas come out of the injector lines? Is there a way to bypass the metering head or a way bench test it to prove its faulty before replacing?
I have no fuel pressure in each ports of the wur. Warm or cold engine. The car run fine but near to 3000-4000tr/min it runs way too rich. Got fuel at the ports but not building pressure at all.
Another great vid. Thanks
Thank you for great demonstration. I have one question regarding the vacuum part of the WUR. I was setting up my WUR after rebuild these days, I was quite puzzled at the beginning but finally I got the point how to adjust the pressures correctly but I was not able to get vacuum working while engine was running, later on after massive investigation I discovered that smaller connection hose coming out of the hose that connects ISV and fifth injector was blind from the production so it was no vacuum comming to this small hose. Anyway I did not understand whats the purpose of this vacuum as I suppose that the vacuum is being produced during whole engine runtime and I cannot imagine in which situation can be this vacuum system used for enrichment of the fuel mixture and how it should work
Thanks, the vacuum is applied to the diaphragm in the WUR when the throttle is closed and partially open, when the throttle is opened there is a lean fueling situation before the extra fuel is delivered to the injectors, to counteract this once vacuum is lost (when the throttle is opened) is reduces control pressure momentarily thus allowing a touch more fuel to overcome the lean patch
That is amazing, but I did not notice any pressure drop during my tests, I suspect that the vacuum lost is not happening in my case, can you tell me which element should cause this behaviour (vacuum lost=pressure drop)? Thanks
@lokvenc672 on the WUR if you blow down the pipe leading into the WUR you shouldn't be able blow through it, if you can the diaphragm will be split
@@GreyGooseRestorations I am not sure if I understand. When vacuum line is disconnected from WUR, pressure drops by around 10psi. I have set the control pressure to around 50-51psi with vacuum line connected, is that correct? Thank you
Yes definitely set all control pressure with pipe in tact, if the pressure is changing when running and the pipe is taken off/clamped then that indicates the vacuum portion is functional
I have watched your video on TH-cam and wondered if I could have a few pointers before purchasing the incorrect parts. I am trying to help out a friend who purchased a non running V6 Volvo from the 80's which has K Jetronic fuel injection. It initially did not start but he found that the in tank fuel pump pipe had rotted away so no fuel was getting to the distributor. In trying to locate the fault he took apart the fuel distributor and could not see any blockages. I then went round and carried out some fuel pressure tests as it starts but once it has warmed up a bit runs very, very rich with thick black smoke from the exhaust. The readings are System Pressure 5.4 Bar (spec 5.5) Control Pressure 2.3 Bar (spec 3-3.4) so the control pressure is low. Would the WUR cause this as I thought that when they fail they usually fail lean ?
WURs normally fail casuing high control pressure.
Low control pressure would cause rich running, was the metering head put back together and set right as it could be at fault sending more fuel to one or more of the injectors
@@GreyGooseRestorations I will have to check, but it seems to run without being too rich when cold, it is only once it begins to warm up that it becomes increasingly rich. Thanks by they way for your response
Great video! I have a WUR without vacuum. It also doesn't have an adjusting screw. How would you suggest I adjust the control pressure? Also, can the screen filter that is in the inlet banjo bolt hole be removed for proper cleaning purposes?
Hi, to adjust that type either modify if like shown with the extra threaded parts to adjust cold and warm pressures.
Its near impossible to remove that flat filter without causing damage unfortunately
The vacuum chamber below wants manifold vacuum or ported vacuum ? The screw in the bottom will affect cold start control pressure and wot enrichment ?
The vacuum chamber needs manifold vacuum (after the throttle body) the allen key behind the brass cover will have an effect on all workings eg cold, warm both with and without vaccuum applied depending how well the wur is or how it's been set previously
@@GreyGooseRestorations Thank you for responding , I appreciate it . K jet is a brilliant system but it’s a bit a bit confusing I’ll admit . I’ve one more question if you’re up for it .
You might laugh at this but I’m running a Mercedes 450 SLC with a rear mounted turbo . I’ve got great warm performance but if I shut it off for even five minutes it starts up chugging and blowing black smoke / stalling . I have an afr ratio sensor / guage installed which has been helpful . I’ve set up the warm mixture with the ( tap the steel cylinder into the wur housing ) method because I didn’t know any better . I’m wondering if my screw at the bottom is adjusted too far out possibly . Thank you for your time . I’ll have to send a few pics / vids of this beast I’ve created , you’ll no doubt get a kick out of it ..
@helmutswetglanz2590 oo that sounds cool, contact me via my Facebook page and i can help
@@GreyGooseRestorations what is your fb profile name ?
I just recently discovered that there is no power coming to the ISV cable (when ignition on), what would you suggest looking at first?
Is there a relay designated for the ISV? Or what else could it be that disrupts ISV power?
It seems to have no cut cable or any visual issue in engine bay.
Behind the centre consol is the ISV control unit. This could be faulty or it could be a power issue
Love the cut aways man, definitely cool to see! I am currently working on an 87 420sel and after rebuilding the fuel distributor I’m not getting any fuel to the injectors but have good pressure at the supply line and a new screen filter at that line too. I’m about to start taking it apart again, what would you think might cause this issue? I’m thinking I placed the diaphragm gasket wrong or something
Thanks, does nothing come out at all when the air flap is raised
@@GreyGooseRestorations I tried to start the car with and without touching the pedal to open and close the air flap and in both circumstances I had only 1 injector line that had a little fuel come out but nothing close to the pressure required to start and it was only 1
Ok unless your CO2 screw is way out your metering head is at fault
Try and turn the 3mm allen key for co2 clockwise wise half a turn, if no better then it'll likely be the metering head
@@GreyGooseRestorations I’ll try and turn the c02 adjustment when I get home, the car ran great when parked and that adjustment hasn’t been touched though so I’m leaning towards the metering head. Even if the c02 adjustment was off though wouldn’t at least some gas come out of the injector lines? Is there a way to bypass the metering head or a way bench test it to prove its faulty before replacing?
That’s funny I’m rebuilding mine to be my daily driver. 😂
I have no fuel pressure in each ports of the wur. Warm or cold engine.
The car run fine but near to 3000-4000tr/min it runs way too rich.
Got fuel at the ports but not building pressure at all.
Sounds like you have some form of blockage