MK2 16V btw This is a weired one, when the elctrical connector on my WUR is disconnected, the car feels a lot quicker/revier and a pleasure to drive and i get 30 mpg on average! With it connected, it feels restricted, slow and sludgy and i get 21 mpg on average! I have swapped the wur over and it's the same! Any ideas guyz?
Try yet another WUR? Or the electrical connector to it is bad? With mine disconnected from cold it is rough as anything and will only just hold an idle from the Idle Stabilisation module, blip the throttle and let the revs come down and it will stall. I believe this to be signs of a working WUR if it's electrical connection is disconneted?
Thanks, that what i thought should happen! maybe others can also varify this! Plugin it in does make a difference like i said origianlly, so i thought that it was all working? Is it possible it's the air flap? as i know the wur reduces fuel pressure, allowing a richer mixture on cold start, but if the flap is already in the correct postion for cold start, when the wur is activated it could be leaning out the mixture way to much - thus make the car run very rich - giving me bad fuel economy? - just gusessing here though - anyone else think this could be right? Thanks
Connecting the electrical connection on the WUR would make the engine run leaner as it would increase the hot control pressure at the metering head. Bit of a strange one... it honestly sounds to me like the WUR is faulty. Have you had the CO setup on a gas analyser with the WUR all connected up?
Yes Smithy, i set it up my self with my Gunston to 2% and i also got it checked at a garage (to make sure the gunston was accurate. Maybe the second hand wur is knackered the same as the original? So does this sound like the wur is stuck open or closed? or maybe somewhere in the middle?
Thinking about it, the only thing it can be is a fault with the WUR. Either that or your system pressure is too high - have shims been added to the regulator in the metering head? You could always get hold of a gauge and setup the WUR yourself.
The metering head is the only place i have not investigated as of yet! where are the shimms supposed to be? regulator in the metering head - have you a pic or diagram? Yeah i need a gauge to set it right i guess! So why does the car run perfect with it disconnceted? will it be a different matter in the winter months?
The regulator is on the right hand side front of the metering head - 16mm nut with an allen head in the centre. You only need a 16mm spanner to remove it. Dont have a pic of it, sorry... but its in the haynes manual if you have one. Standard spec for hot WUR control pressure is 48-53PSI at idle. If the system pressure has been increased then the control pressure will have increased too, which would explain why it runs "right" with the electrical connection disconnected. (disconnecting the plug on the WUR will lower the control pressure). Either that or the WUR is just a duffer.
Thanks mate great help! - i have a haynes - i'll have a look! - why would shimms of been added, what would this do? Where can you get a fuel pressure gauge from? and where is it best to connect it up - at the wur end or metering head? Also i will try a few more wurs i think, there pretty cheap on ebay sorry for all the questions!
Adding shims to the regulator will basically increase the system pressure. Cant quite remember but the working pressure is (i think) anywhere between 4.5 and 5.5 bar. Its just a wild guess that someonce has done this, might not be the case at all. You can get a gauge from www.fuelsystem.co.uk but you will have to make up your own lines for it... you will have to connect it on the supply line between the WUR and metering head.
Thanks! I am sure pigbladder did this test! so the shimms could have been added if the wur was knackered, to compenstate! I just check the website out and the fuel gauges only have a range of 0-15 Psi? i thought ideal pressure was about 49 psi or have i missed something? Cheers! great help mate! Edited by: gti_kev
O yeah, my brain just read 7 psi I justread through the the top sticky again (for the 5th time), looks like it could be the control pressure is the cause that and a knackered WUR The gauge will tell all i guess! cheers
Just because the CO reads 2% doesn't mean the engine is running right. Only using a 4 gas analyser can you truely say whether the engine is running right. For example, if you have a weak injector not spraying correctly, when you set the CO to 2% you may have 3 cylinders running rich to compensate for the knackered one. If there's a change when the electrical connection is connected then the WUR is obviously partially working. It could as the guys say be down to high control pressure (WUR knackered) but it could also mean you have another fault that only shows when the control pressure is raised and the mixture weakens. Edited by: Golden
Very true! it's never black or white in this game I don't know anyone with another 16V, if i did we could swap over the wur's so i could at least rule that out! Anyone got a known working wur? I am trying to get hold of a fuel pressure gauge, so i can at least see if the pressure is ok! Injectors are on the list, been a bit hesitant to pull them, as the car is for work, so it can't be off the road!
Kev - get yourself a pressure gauge and test/set up the control pressure and system pressure correctly. I spent months messing around changing bits and bobs, fixing wiring, swapped fuel pump, accumulator and alsorts and still couldn't fix my cold start problem. Pressure gauge diagnosed faulty WUR in about 30 mins, bought a secondhand one from a forum member, fitted it and set up pressures and been great since!
I think you'll need a couple of k-jet hoses and correct size banjo fittings. Depends what comes in the kit, the gauge I used I borrowed and it already had the correct fittings on it.
Not got it anymore I'm afraid, thinking of buying one myself now anyway to set up the 2 litre 16v as the postage to borrow and return the gauge worked out nearly as expensive as buying one last time!
