Hi , Having a bit trouble testing fuel system - distributor to WUR , my instructions say to do it with the electrical connector on but i read online to take it off, Can someone please explain how to do it and do i have to run the car or just ignition/fuel pump on? Thanks.

 

Depends what you're trying to achieve..

If you want to measure cold pressure only then fuel pump running but plug off (if engine is running bare in mind you'll get heat transfer effecting the WUR).

If you want to measure the WUR and heated element are working, then either engine running or bridge the fuel pump relay with a yellow relay (nab one out your fusebox temporarily) and you should see a steady pressure change until upto (heated element) temp

 

Yea cold and system pressure. Still having trouble starting when the engines cold. Done a compression test was all good.
Went out this morning to get readings and the pain in the erse started first time! Even let me use the accelerator without cutting out quicker. The only difference was that i left the valve closed last night. So the readings were Valve open 3.2bars. And closed it didnt change 3.2 bars - not sure if the closed valve from last night affected these so il try again with it open in few hours but possibly low system pressure? Thanks

 

Valve open? Which valve?

3.2 bar is too low for warm control pressure, it should be between 3,4 and 3,8 bar.
Cold control pressure is somewhere between 0,75 and 1,25 bar @ 10°C outside temperature.
At 0°C outside temperature we're talking about 0,25 to 0,75 bar.

 

I assume theres a locking valve on his fuel pressure tester.
Although I agree its out of spec (for standard) 3.2 will run fine warm, albeit a tad rich. WUR's are seldom linear after years of use, but its possible if warm pressure if low, cold pressure is too low for the outside temp so defininetely need to narrow down your starting pressure.

 

Sorry yea theres a locking valve on the fuel tester.
That was the specs stone cold , Same everyday - going to try again in half hour. The cars great when its warm.
So could it be that anything in the fuel system before the fuel pressure tester is blocked ( does this include the wur? )or one of the parts failing to produce the power to push the fuel through? What else should i be checking? would fuel tank pressure affect this? And i also seen air in the fuel return line , is that meant to be there?? Cheers

 

Before anything, can you confirm exactly how you have the pressure tester set up?

 

Its on the middle top of the fuel distributor and the wur where the 4/5 gauzes are.
My test this morning was still 3.2 cold - valve open , but when i closed it this time it went to 4 bar. cheers

 

Connected to the little or large port on the WUR?

 

Sure it was a larger one , its the top one if that helps? Can upload a pic too.

 

Top ones correct, just wanted to make sure we were taking the right readings first and foremost.

High cold pressure suggests blockage somewhere. Check the gauze on both inlet and outlet of WUR are spotless - an airline to blow through at the end doesnt do any harm. I tend to strip down WUR's completely and ensure there is no build up on the pressure disk too (i also modify to make them adjustable if I've gone to the hassle of taking it off at this point but lets not go there at this stage)

The below is a very crude test (shamelessly nicked cause I couldn't be bothered to rewrite at 6am), and I take zero responsibility for the risks involved. Have a fire extinguisher, plenty of rags to hand:
- crack open the INLET to the WUR - if fuel sprays, and pressure drops, problem is further along. If pressure DOESNT drop, problem is in the line back to distributor.
- crack open OUTLET of WUR - if pressure drops, problem is further along; if little fuel emerges, and pressure doesnt drop, problem is in WUR.
- crack open return line outlet at distributor - same comments as above.
- crack open return line entry to tank gauge head, apply same comments as above.

 

What about a not working warm-up regulator?

 

Hahaha you forgot the NOT TO SMOKE ... Thanks for your time haz , really appreciate it especially at they times. Mate i never asked if you had a classic? Your knowledge is right up there and putting the bolt on the wur to adjust it is defo something else was just reading it the other day saved the page just in case. I actually enjoy learning all this cheers.
I cleaned the wur gauzes the other day they were absolutely covered in dirt ( thought it would have been rust ). Is there any other hidden gauzes i should be checking?
Last year i also replaced the hefty rusty fuel tank and new pump.
Il get those checks done then is it worth disconnecting all the fuel lines and giving them a blow through?

 

Theres only two elements that can really not work - the heating element - which it isn't that as we'd be stuck at low pressures opposed to high, or the o-ring/disc assembly, which I have never seen go wrong beyond crud build up on them.
I'm not saying there isn't the possibility of some other anomaly, but they are unbelievably simple (as with all k-jet gear, people are just scared on them - I know you are familiar with all this stuff so not tarring you with that brush) and a couple of basic tests and a strip down/clean up will usually sort most of them.

 

Built more 3i engines or n/a ZVH's than I can remember, and almost all of them happened to be on K-Jet so its just a system I'm comfortable with. Seems to be a complete lack of info and education in the Ford world as people just write it off as shit - yet if you look at the VW (early Golf usually) or Porsche guys, theres a plethora of information. Hell I used to even trawl Ferrari forums years back as they'd talk more about it than Ford guys

There is definitely no harm in blowing through the lines, especially if the tank was rotted out, feed/return inclusive. The metering unit could be gunked up/blocked up but that definitely becomes a more complex task to tackle if it needs stripping. I guess theres no reason the Accumulator couldn't gunk too (cylinder sitting on the inner wing), tho you could measure fuel pressure before/after to get a decent idea on that one.

There is also a pressure relief valve in the metering unit (hidden behind a 16mm hex iirc) that can jam up and influence pressure. Equally you can pack these out to increase pressure - someone may have done this to hide a low pressure in a previous life, so worth removing and at least ensuring its clean and moving freely and hasn't been tampered with...

 

Yea the infos all over the place.
Defo dont have extra shims its good condition inside. My mates not up for helping with cranking the bolts lol so i will do that last resort.
Whats this called ( Attached to fuel line - im assuming a valve ) and how do i get it off , just going to replace them.