What should warm up regulator control pressures be, cold and warm? For escort mk4 xr3i mfi, the wur without vacuum

 

What temp cold - it makes a difference. You show as in Finland so your cold is very different to UK cold....

Hot running engine you should see somewhere around the 3.6 to 3.8 bar mark

 

I have the car in the garage, around 15celsius inside

 

Can't find my chart at the moment but it will be in the benchmark of 0.5-1.5bar - obviously with heater element disconnected as that will very quickly start changing things

Correction on hot pressure tho having had some sleep, the tolerance range is actually 3.4 - 3.8

 

I got 0,75bar pressure at about 18°C cold engine and 3,4bar warm

 

A tad on the low side so the car will be a little rich throughout but definitely far from out of spec.Will actually work well if the engine is modified (headwork,cams,etc)
Easily rectified if you're that bothered tho or the engine is bog standard

 

Engine is modified, but it wont idle. The engine runs good over 2000rpm but if I let go off the gas pedal then it dies

 

Unlikely to be fuel pressure if you're seeing 3.4 hot. Vac leaks will create hell so worth checking for those.
Checked ignition timing with vac disconnected/plugged? Base fuel mixture? Cam timing?

 

Depending on the history of the car too, if its been sitting around it could be gunked up injectors or just knackered/poor pattern injectors. Always worth swapping them out for new (and even new can be a bit crap) if its sat for any length of time or you have no idea when they were last changed.

 

Almost every part is new or cleaned and tested with new seals. I tried to change ignition timing but no diffrence for idle. Fuel mixture I dont know about, I have tried to have the mixture screw open a lot and almost closed

 

Ignition timing should make a difference at idle - Not huge but you should definitely be able to hear a notable difference between say 6btdc to 16btdc.
Before I comment further, which screw are you turning for fuel mixture? Just to check we're on the right page there...

 

I do hear a diffrence when adjusting ignition timing but still wont idle. The 3mm allen key CO screw on the airbox

 

Ok cool - right place at least.
There is a sweet spot that you can usually find by ear, but I'm not going to try and even put it to words for fear of getting torn apart by others. So I'll go with the probably best to get a CO analyser on it and set the mixture up that way. Going to the extremes of either end definitely shouldn't be required tho - outside of a fairly small range the car would die on lean/richness alone from fiddling with that screw.

Think we're going to need some background of where this issue has started. Was it fine then just stopped idling? Is it just idling badly or does it just die (both hot and cold)? Even when its idling badly, if you apply throttle does it then pick up cleanly (I know you said 2k onwards is fine, but from idle to that?)? Cars modified - with what exactly?

These engines aren't difficult, but people have a habit of not understanding them too well so things get "fiddled" a bit too much which can make it a pain to set right blindly.

Basic things I check on any MFI assuming it hasn't been sat in a barn for months or years without running, not in any particular order:
Vac leaks
Fuel filter changed recently (~6months)
Ignition timing
Cam timing (bear in mind if this is out or you change it, it will alter ignition timing)
Rotor arm and dizzee cap in good condition
Fuel pressure
Fuel Mixture
Plugs
TB adjustment

Again some of the above will impact other things. Alter cam timing and you'll move ignition timing, alter TB setting will impact mixture etc etc so its just a case of going through it logically.
Things like coils or the distributor unit can and do go, but they are unlikely to cause poor idle only IME

 

Engine was built years ago but has never been used after the rebuild. The block is bored to 1,74l from a 1,6l. Head is ported and dropped 2mm lower and it has a 279 cam, it was built to be a high compression engine. The Mfi is from a diffrent engine that hasnt been running in probably 6 or 7 years.
All ignition parts are new and all fuel parts are new except fuel accumulator, aux air valve, distributor, metering unit and cold start injector but they have been tested that they work and been cleaned and new seals installed.
Fuel pressure is good, cold and hot and system pressure.
New vac lines and clamps.
The car starts good when cold and hot and revs good after 2000rpm. The problem is that if I let go off the gas pedal and rpm drops below 2000rpm it dies instantly so it wont idle at all

 

Have you checked the movement of the plunger in the metering unit? If its a bit gummed up it may be slow to respond and only when the revs are up and demand is raised is the flap beginning to lift enough for the engine to rev cleanly.
I know you say you've tested everything but just make sure the cold start injector isn't jammed open.


Regardless of root cause you're still going to need to get the fuel mixture right for this to idle properly. A few too many degrees clockwise or counter and it'll be wanting to die regardless if everything else is perfect.

 

The plunger does work good and the flap. I put a small camera in there too see when starting the car.
I will try to get the right fuel mixture and maybe a afr gauge or bring the car somewhere to be tested for CO and test the cold start injector or disconnect it first to test if it runs better or idle.

 

I checked the cold start injector and it was working as it should. I then tried to adjust mixture screw to only 1 turn open and it would not run or start good. Then I turned the screw 5 turns open and then it started to idle at 2000rpm for 1 minute and then died but started good and revs good but didnt idle anymore after 1 minute but after waiting 5 minutes to cool down, then it started to idle again at 2000rpm for 1minute.
Is it possible to lower wur pressure to make it a little more rich if needed?

 

Your WUR range is already on the rich side. Lower pressure = rich, so 3.4 is at the rich end hot where as 3.8 would be the leaner side (hot).

Sounds like your adjustment simply isn't right. Demands will be different from stone cold to even only a minute running. The AAV will have started closing, the WUR will have started leaning out the mixture (as rate is raising) so sounds like your base mixture (allen adjustment) was slightly too lean. Go slightly counter clockwise from where you are and try again. We're talking a fifth of a turn, not an entire rotation etc. The closer you get to it being right, the smaller the adjustments. Not on even the worst car I've had to set up have I had to go more than 2 turns in either direction - the fact you've been from end to end means you could be anywhere at the mo.

 

I got the car to run on idle at about 1200rpm. It was just that the fuel mixture that was not correct, I had to go a little richer. It's a little under 6 turns open now. I'm going to get a afr gauge next to see the mixture and some fine tuning other stuff like the throttle body idle screw and ignition timing