Hi recently on my MK2 16v I noticed that the plug that was in the WUR was actually for the thermotime switch for the cold start system (2 pin brown plug). I’ve been trying to diagnose why my car has been running rich (failing mot on emssions too) could this possibly be why? Ignition timing done, new spark plugs, new injectors and a good clean of the intake system has already been completed 😎 I did find the wires that I believe are for the WUR so I’ve ordered a new 2 pin plug to give them a go.
No problems, sounds like the pin could be stuck, had this on another MK2 16v recently, it would idle perfect but once warm wouldn't idle, the WUR was providing system pressure (5.5Bar) to the control pressure side, nearly 2bar more than it should be, it was trying to push the fuel plunger down when the air meter was trying to push it up.
Great video, my problem is hard start when hot, can this regulator cause that symptom. Ive replaced injectors, fuel pump and check valve, and fuel compensator.
Hi, that's a very useful video. I have a 928 with a starting issue. Many years ago the car would start from cold and tickover at 1500 revs until warm. Now it struggles to start at all, picking up a couple of cylinders at a time. The resistance of the bi metallic strip is spot on at 26.5ohms but there is no voltage coming to the connector with the ignition on. Is there a relay for the wur?
The WUR filter may be blocked as they are a triple layer and you will never clean them, i pull the filter out and fit a cone filter into the banjo bolt. The warm up element even if no voltage will allow the car to start and run it would just take longer for the warm control pressure to be achieved. I don't believe it is relay controlled just a direct 12v feed
Hello, got an 84 granada 2.8 injection, runs perfect but wont start when its cold if i not turn on the meter head slightly.. could this be the problem?
Firstly i love a Granada, it could be the metering head (C02%) put of adjustment or the cold start injector not working causing cold start issue providing all fuel pressues are spot on
Hi, have a '91 16v golf gti that I have managed to get running starts and idles fine after alot of effort, there is an issue where it doesn't seem to like initial application of throttle it sort of bogs down. It sounds like is drawing in air somewhere but can't see any obvious leaks. Liked this video and think it will have to go on the ever growing list of jobs !!
Might just need a tweek on the fuel metering head, it may just be dipping into lean fueling as soon as the throttle is applied before it then gets back in to normal fueling
The injectors may be clogged, they need 3.5Bar of pressure to open and that increases if they get dirty. This causes a hesitation on blipping the throttle
I have a 86 GTI with the 1.8 CIS KJet.. I had someone rebuild my kjet unit with new gaskets and now it only runs for a few minutes and starts to lose power until it dies. Usually like 3-8 minutes. Do you think this part might have something to do with it?
Nice series of explanations - thanks, they've been a great motivator. Quick question: What does the vacuum hose on the side of the WUR connect to? Does it provide altitude enrichment or adjust the control pressure based upon manifold vacuum?
Hi, my system pressure and return fuel volumes are very good being within the vehicle's specifications and I'm getting correct and equal flow to all the fuel injectors when jumping the fuel pump relay and pushing the air sensor plate to WOT. But my cold control pressure is very low - less than the specified pressure at 0 degrees. What do you think is the issue with the WUR that would cause this? Thanks.
Normally the control fuel pressure is about 0.5 bar at cold start and about 3.7 bar with the engine at normal operating temperature. If your cold control pressure is below the specified fuel pressure then your engine must have been running on a richer mixture when cold and through out the whole range. Mainly the parts that can cause this problem is the warm-up regulator. High control pressure and pressure not being regulated is the common fault of the warm-up regulator, a low pressure can happen if the bimetallic spring has been over adjusted manually trying to reduce or lower the control pressure.
Hi Can the WUR stop the car starting/running. Although not tested the fuel pressure I do appear to have high pressure being delivered to the metering unit and the 5th injector working but no fuel to the other injectors. The car will start but then immediately cuts out. What should I be looking at next TIA
First guess would be the fuel plunger that is in the centre of the metering unit, these are common for sticking and stop fuel to the injectors, the engines probably using the fuel from the 5th injector to initially fire up. Unbolt the metering head from the air box and the plunger can be accessed from there
@@GreyGooseRestorations ok just checked the plunger and seems free have also removed one of the injectors and operated the fuel pump with the plunger pushed in a fuel is getting to the injector but seems not enough pressure to open it.
Great explanation. You were recommended as someone to speak to about my kjet issues. I've got a hot start problem which has developed all of a sudden. I've done some pressure testing this evening and the control pressure seems really high. 5 bar system pressure, 4.6 bar control. Would this be the issue do you think? System held pressure for 30mins after switching off, only dropped from 4.6 to 4bar. Appreciate any advice you may be able to offer. It's an 8v GTI. Thanks!
Hi I have a 1991 golf gti 16v KR and it fails to start when warm. It cold and hot starts fine but if you leave it over 10 mins it struggles a bit and take a few seconds of cranking then seems to start but not on all cylinders. If I leave it over an hour it takes at least a good minute of cranking to start. Could this be the WUR? Many thanks
Hi, it sounds like it could be the WUR but my first port of call would be to check the fuel pressures as if its not holding residual pressure that will cause this.
Great vid thanks! This has given me the confidence to take mine apart which I am doing currently. Resistance seems fine so all good there. I did find that the very thin circle piece of metal was firmly stuck could this be an indicator of the WUR not working? There was also some grease build up too.
Thanks, yeah it should all be clean just a tiny bit of grease in the cone part where the pin locates. If the disc was hard to remove then that would indicate to me it wasn't functioning
Hi, I hope that you check your messages once in a while. I have an issue with a 1986 VW Cabriolet that maybe you'd be willing to help with. Upon start up, when the car is cold, we have to start the car up 5-6-7-8 times in a row before it will stay running. Usually it will start run for a second or two then the rpms drop to zero and she stalls, even if we try to press the gas to prevent rpms from crashing to zero - actually ESPECIALLY if we press the gas - when we press gas it is like choking the car off from either its gas or air supply (All Out of Love)😆. Once we have gone through the multiple startup sequences and she holds her rpms and runs on fast idle, again if we press the gas, she chokes. Once shes warmed up, everything is absolutely normal, holds rpms at around 800 and gas is perfectly fine. Press the gas peddle and she's perfectly crisp. We changed plugs, wires, rotor and I just rebuilt the WUR - no improvement. Not sure what to do or check next. If you can, please help me. Thanks.
Hi, are you able to test your fuel pressures? This will give a good indication to your problem. Also have you checked your C02% and ignition timing advance?
@@GreyGooseRestorations Hi, thanks for the reply. I have a lot going on right now but I will find time and guage to check fuel pressure. I'm assuming that we want to check both when engine is hot and cold. I checked the ignition timing last summer when we changed rotors/plugs and wires, it was setup right, however the car had the cold start condition issue before and after our ignition check, so I don't think that is it. We put in *new plugs, wires, rotor, distr. cap and checked timing* Also, worth noting, the previous owners got 'handy' and 'crafty' with the wiring and some electrical stuff in the car doesn't work. Both the heat and fuel guage, the heater fan blower switch starts the radiator fan...So, let's assume that my Jetronic ECU isn't getting power and this car is strictly analogue right now...Should my WUR be supplying extra fuel anyways? Would the 5th injector be still functionnal? I popped out the Jetronic ECU and looked inside, it looks beautiful. There are no signs of heat or oxidation. As far as the CO2, I wanted to measure the fuel/air ratio using the electrical connector near the 5th injector but it gave no reading. Hopefully, this gives us something to go on. Thank you very much for your help.
Older K-jetronic doesn't have the ability to measure AFR. C02 is very important as even a 1/8th turn the wrong way will cause starting issues. With fuel pressure you want the car cold and monitor pressures as the engine warms up
Great explanation and very helpful. Thanks for sharing your expertise.
Thanks, happy to help others
Hi recently on my MK2 16v I noticed that the plug that was in the WUR was actually for the thermotime switch for the cold start system (2 pin brown plug). I’ve been trying to diagnose why my car has been running rich (failing mot on emssions too) could this possibly be why? Ignition timing done, new spark plugs, new injectors and a good clean of the intake system has already been completed 😎 I did find the wires that I believe are for the WUR so I’ve ordered a new 2 pin plug to give them a go.
It could well be yes if it's running too rich
@@GreyGooseRestorationsthank you!!
Thank you for posting this , I am about to do this job on a Capri 2.8. It starts but does not want to rev until it has warmed up .
No problems, sounds like the pin could be stuck, had this on another MK2 16v recently, it would idle perfect but once warm wouldn't idle, the WUR was providing system pressure (5.5Bar) to the control pressure side, nearly 2bar more than it should be, it was trying to push the fuel plunger down when the air meter was trying to push it up.
Would you by chance happen to have a rebuild kit for the warm-up regulator to my 1976 Mercedes Benz 450 SL?
Yes i can supply these, if you message me over on my Facebook page Grey Goose Restorations with the part number off the WUR i can get you a price 👍
Great video, my problem is hard start when hot, can this regulator cause that symptom. Ive replaced injectors, fuel pump and check valve, and fuel compensator.
Yes that is a common WUR issue
Hi, that's a very useful video. I have a 928 with a starting issue. Many years ago the car would start from cold and tickover at 1500 revs until warm. Now it struggles to start at all, picking up a couple of cylinders at a time. The resistance of the bi metallic strip is spot on at 26.5ohms but there is no voltage coming to the connector with the ignition on. Is there a relay for the wur?
The WUR filter may be blocked as they are a triple layer and you will never clean them, i pull the filter out and fit a cone filter into the banjo bolt.
The warm up element even if no voltage will allow the car to start and run it would just take longer for the warm control pressure to be achieved.
I don't believe it is relay controlled just a direct 12v feed
@@GreyGooseRestorations Many thanks.
Hello, got an 84 granada 2.8 injection, runs perfect but wont start when its cold if i not turn on the meter head slightly.. could this be the problem?
Firstly i love a Granada, it could be the metering head (C02%) put of adjustment or the cold start injector not working causing cold start issue providing all fuel pressues are spot on
Hi, have a '91 16v golf gti that I have managed to get running starts and idles fine after alot of effort, there is an issue where it doesn't seem to like initial application of throttle it sort of bogs down. It sounds like is drawing in air somewhere but can't see any obvious leaks.
Liked this video and think it will have to go on the ever growing list of jobs !!
Might just need a tweek on the fuel metering head, it may just be dipping into lean fueling as soon as the throttle is applied before it then gets back in to normal fueling
The injectors may be clogged, they need 3.5Bar of pressure to open and that increases if they get dirty. This causes a hesitation on blipping the throttle
I have a 86 GTI with the 1.8 CIS KJet.. I had someone rebuild my kjet unit with new gaskets and now it only runs for a few minutes and starts to lose power until it dies. Usually like 3-8 minutes. Do you think this part might have something to do with it?
Most likely, if it was running before and now its not then somethings not right, it could be simple to fix or it may need a rebuild again
Great Job Grey, would you help me with the WUR wiring connection digram with CE2
Happy to help
Thank you Gery for your reply ..here's my email if u liked to send digram sheet hossamahmedezat@yahoo.com
Sounds like a choke to me, is it necessary in mild climate, can't I just by pass it?
Nope, it can't be bypassed
Nice series of explanations - thanks, they've been a great motivator. Quick question: What does the vacuum hose on the side of the WUR connect to? Does it provide altitude enrichment or adjust the control pressure based upon manifold vacuum?
Thanks, it connects too the lower part of the inlet manifold and adjusts fueling relative to open or closed throttle
Hi, my system pressure and return fuel volumes are very good being within the vehicle's specifications and I'm getting correct and equal flow to all the fuel injectors when jumping the fuel pump relay and pushing the air sensor plate to WOT. But my cold control pressure is very low - less than the specified pressure at 0 degrees. What do you think is the issue with the WUR that would cause this? Thanks.
Hi, if your cold control pressure is very low then its most likey the WUR at fault
Normally the control fuel pressure is about 0.5 bar at cold start and about 3.7 bar with the engine at normal operating temperature. If your cold control pressure is below the specified fuel pressure then your engine must have been running on a richer mixture when cold and through out the whole range. Mainly the parts that can cause this problem is the warm-up regulator. High control pressure and pressure not being regulated is the common fault of the warm-up regulator, a low pressure can happen if the bimetallic spring has been over adjusted manually trying to reduce or lower the control pressure.
Is this necessary in mild climate, sounds like a choke to me?
For the engine to work correctly and perform its got to be working
Hi Can the WUR stop the car starting/running. Although not tested the fuel pressure I do appear to have high pressure being delivered to the metering unit and the 5th injector working but no fuel to the other injectors. The car will start but then immediately cuts out. What should I be looking at next TIA
First guess would be the fuel plunger that is in the centre of the metering unit, these are common for sticking and stop fuel to the injectors, the engines probably using the fuel from the 5th injector to initially fire up.
Unbolt the metering head from the air box and the plunger can be accessed from there
@@GreyGooseRestorations ok just checked the plunger and seems free have also removed one of the injectors and operated the fuel pump with the plunger pushed in a fuel is getting to the injector but seems not enough pressure to open it.
@@ronnie8752 ok ideally you need to check the system pressure that should be approx. 5bar the injectors won't open untill approx. 3bar.
@@GreyGooseRestorations ok thanks I don't have a pressure tester. Will see if I can get hold of one from somewhere 👍
Great explanation. You were recommended as someone to speak to about my kjet issues. I've got a hot start problem which has developed all of a sudden. I've done some pressure testing this evening and the control pressure seems really high. 5 bar system pressure, 4.6 bar control. Would this be the issue do you think? System held pressure for 30mins after switching off, only dropped from 4.6 to 4bar. Appreciate any advice you may be able to offer. It's an 8v GTI. Thanks!
Hi I have a 1991 golf gti 16v KR and it fails to start when warm. It cold and hot starts fine but if you leave it over 10 mins it struggles a bit and take a few seconds of cranking then seems to start but not on all cylinders. If I leave it over an hour it takes at least a good minute of cranking to start. Could this be the WUR? Many thanks
Hi, it sounds like it could be the WUR but my first port of call would be to check the fuel pressures as if its not holding residual pressure that will cause this.
@@GreyGooseRestorations many thanks, will try to check this as soon as I’m back with the car
My WUR diaphragm has split. Trying to find a rebuild kit. 🤦♂️
I can refurbish these or supply full kits, message me over on my Facebook page 👍
@@GreyGooseRestorations hi,what is the name of your facebook page please ?
Grey Goose Restorations 👍
Great vid thanks! This has given me the confidence to take mine apart which I am doing currently. Resistance seems fine so all good there. I did find that the very thin circle piece of metal was firmly stuck could this be an indicator of the WUR not working? There was also some grease build up too.
Thanks, yeah it should all be clean just a tiny bit of grease in the cone part where the pin locates. If the disc was hard to remove then that would indicate to me it wasn't functioning
Ok great do you have any videos for adjustment ??
I Don't as yet but i can try and do one soon
Hi, I hope that you check your messages once in a while. I have an issue with a 1986 VW Cabriolet that maybe you'd be willing to help with. Upon start up, when the car is cold, we have to start the car up 5-6-7-8 times in a row before it will stay running. Usually it will start run for a second or two then the rpms drop to zero and she stalls, even if we try to press the gas to prevent rpms from crashing to zero - actually ESPECIALLY if we press the gas - when we press gas it is like choking the car off from either its gas or air supply (All Out of Love)😆. Once we have gone through the multiple startup sequences and she holds her rpms and runs on fast idle, again if we press the gas, she chokes. Once shes warmed up, everything is absolutely normal, holds rpms at around 800 and gas is perfectly fine. Press the gas peddle and she's perfectly crisp. We changed plugs, wires, rotor and I just rebuilt the WUR - no improvement. Not sure what to do or check next. If you can, please help me. Thanks.
Hi, are you able to test your fuel pressures? This will give a good indication to your problem.
Also have you checked your C02% and ignition timing advance?
@@GreyGooseRestorations Hi, thanks for the reply. I have a lot going on right now but I will find time and guage to check fuel pressure. I'm assuming that we want to check both when engine is hot and cold. I checked the ignition timing last summer when we changed rotors/plugs and wires, it was setup right, however the car had the cold start condition issue before and after our ignition check, so I don't think that is it. We put in *new plugs, wires, rotor, distr. cap and checked timing*
Also, worth noting, the previous owners got 'handy' and 'crafty' with the wiring and some electrical stuff in the car doesn't work. Both the heat and fuel guage, the heater fan blower switch starts the radiator fan...So, let's assume that my Jetronic ECU isn't getting power and this car is strictly analogue right now...Should my WUR be supplying extra fuel anyways? Would the 5th injector be still functionnal? I popped out the Jetronic ECU and looked inside, it looks beautiful. There are no signs of heat or oxidation.
As far as the CO2, I wanted to measure the fuel/air ratio using the electrical connector near the 5th injector but it gave no reading.
Hopefully, this gives us something to go on. Thank you very much for your help.
Older K-jetronic doesn't have the ability to measure AFR.
C02 is very important as even a 1/8th turn the wrong way will cause starting issues.
With fuel pressure you want the car cold and monitor pressures as the engine warms up
@@GreyGooseRestorations Exactly what do these older Jetronic ECUs do? And how important is it that I get mine back on line?
They only control the spark advance relevant to engine vacuum. Its very important its all functional
My understanding is that this valve is working electricaly becos i see a plug on my Jetta A2 Kjetronic 16valve system
The plug is just for the heating element which assists in the warming up along with the heat transfer from the cylinder head