8v GTi PROBLEM HELP ***LATEST UPDATE 9th MAY***

Have you swapped the coil yet? Symptoms identical to coil breaking down when hot.

dubboy said

Have you swapped the coil yet? Symptoms identical to coil breaking down when hot.

yes mate i have swapped the coil BUT it was a 2nd hand one. do you reckon i should buy a brand new one?

by the way people, i have been out on it for most of today, and did pull off a injector and put it inside a bottle then crank the engine to see if any fuel was being delivered to the block. a tiny little bit came out and that was it.

**Jamez and Al!!!**

when you say strip down the metering head, do you simply mean take it off and give it a clean somehow? i haven't tried another on it and at the moment dont have access to one either.

i've heard that you also have to be careful off pushing the plate down from the top? is this true?

are there any other bits and pieces/details you think i should know before i go out there and take it all apart?

i totally agree with you that the evidence does seem to be pointing towards the metering head so i want to fix it but i want to do it right!

thanks once again so far :wink: really REALLY appreciate it!

Take the whole top of the airbox off. Just a couple of spring clips and a few fuel lines. It doesn't matter which fuel injector is connected to which outlet, so don't worry too much about mixing them up!

The square piece on the top comes off (4 bolts) and that then comes apart revealing the central sliding plunger, which is operated by the "Flap", which will also now be visible and easy to look at, as it is part of the bit you have removed!

The sliding plunger should be scratch free and should not stick at all during its operation. It should all be spankingly clean inside too as it is always full of fuel.
There is a pressure operated (spring controlled) valve on the outlet that sends fuel back to the tank (During idle/low throttle conditions). Depending on the engine the metering head has come off, there will be a spring and a series of spacers, which determine the pressure at which this valve opens. Check this out. If its operation is not smooth, it may be sticking open, meaning you have too much fuel taking the easy route back to tank instead of being delivered through your injectors. Perhaps the spring is broken? I wouldn't mess about with adding or removing washers though as the opening pressure of this valve is pretty critical.

Swapping the whole unit out is a 20 min job if you can borrow one from someone first to do a test?

Hope that is of some help!

AL_Mk1 said

Hope that is of some help!

lovely jubbly thanks Al!!!

just another quick update since i wrote the above post.

i've been out to the car and got it running and up to temperature. it ran fine for the first 5 mins then got lumpy, the idle revs started to die down till it cut out.

tried to start it but it wouldn't fire(as usual) SO, i i did what was suggested and lifted the metering head plate a couple of times, went back and it started first time although i had to give it some revs to keep it alive. as soon as i left the throttle the car cut out again.

why does the metering head plate struggle to open once the car is hot to allow the fuel through?

when you lift the plate this raises the plunger in the metering head to allow fuel to the injectors.when the engine stalls, there is no signal from the coil so the fuel pump will stop. in this case there is residual pressure remaining in the fuel line, the idea is the this pressure will aid in the next start.

with out it the fuel pump must run for a few seconds till there is enough pressure to open the injectors, so only the first lift will add fuel directly into the cylinders. when you start the fuel pressure must again build up.

the next thing to conclude that the metering head is at fault is to get the engine started and with one hand open the trottle valve a bit and at the same time raise the flap manually.

if the engine runs and stays running wilst doing this, this points directly to a faulty metering valve or wur.

if the wur was really dead it is possible that when warm it is allowing alot of pressure to return to the tank, and hence a stall.

secondly remove the 12v connection to the wur at the front of the block and see if the engine will run for a longer period of time from cold.

as for why it dose this only when hot,………………………
requires further thought…..i'm thinking :posh:

jamez said

as for why it dose this only when hot,………………………
requires further thought…..i'm thinking :posh:

you're like some kind of k-jet guru!!! 8)

i tried lifting the plate at the same time as pulling the throttle cable. the car made a big induction noise then cut out. i tried it a couple of times and it kept dying unless i open the throttle valve wide open by pulling the cable right out so that it was revving around 4.5k. BUT, because it is hot as soon as i let go of the throttle the revs die back to 500 straight away then it cuts out again obviously because there is then now fuel in the block.

by the way, what should the voltage output be from the plug that goes to the WUR??? should it constantly be 12v??

the fact that the engine did run says that the metering head is working, you'll never get it to run properly buy manually lifting the plate but it show that fuel is present.

i just read the first post again, and have another idea.

the wur at the front has a 12v supply. upon start up from cold extra fuel from the metering head is added via the wur to the 5th injector, like a choke.inside the wur is a small bimetal strip with a heater attached. as the heater warms the bimetal strip it bends. this moves a small valve witch lowers the fuel to the 5th injector, and eventually stops altogether.

if the heather element was dead or there was no

 voltage, the 5th injector would run all the time. from cold this is the idea as a cold engine needs it, but when warm could cause the engine to run really rich. hence the engine getting really hot, then like a carb. engine with the choke on all the time, it will eventually stall and flood.

the wur also gets heat from the block it self for the same reason.
possiblly the engine is flooding, when it stalls remove a spark plug and see if it is wet with fuel , if it is then i'd say that its flooded,

when you leave it for an hour, it cools and the extra fuel evaporates.

give it a go.

jamez said

the fact that the engine did run says that the metering head is working, you'll never get it to run properly buy manually lifting the plate but it show that fuel is present.

i just read the first post again, and have another idea.

the wur at the front has a 12v supply. upon start up from cold extra fuel from the metering head is added via the wur to the 5th injector, like a choke.inside the wur is a small bimetal strip with a heater attached. as the heater warms the bimetal strip it bends. this moves a small valve witch lowers the fuel to the 5th injector, and eventually stops altogether.

if the heather element was dead or there was no

 voltage, the 5th injector would run all the time. from cold this is the idea as a cold engine needs it, but when warm could cause the engine to run really rich. hence the engine getting really hot, then like a carb. engine with the choke on all the time, it will eventually stall and flood.

the wur also gets heat from the block it self for the same reason.
possiblly the engine is flooding, when it stalls remove a spark plug and see if it is wet with fuel , if it is then i'd say that its flooded,

when you leave it for an hour, it cools and the extra fuel evaporates.

give it a go.

Not true.

The 5th injector only fires during startup, and only for 0-10 seconds or so. Its controlled by the thermo time switch, which measures the temperature of the coolant and alters the length of time it opens the 5th injector (cold start valve) for. But, because the 5th injector fires into the inlet manifold, and not directly to the cylinder(s), the 'cloud' of fuel vapour lingers around and has an effect on the mixture for around 30-45 seconds after initial startup.

The warm up regulator is important because its impossible to bypass or otherwise avoid it. It has a heating element and is attached to the block, both these things warm it up and this moves a bimetallic element which alters a valve in it, which alters the fuel pressure. This then, combined with a valve in the fuel metering head (which moves up and down by a lever, according to where the air flap is) controls the fuel pressure the injectors see. This then controls how long they are open, hence the amount of fuel delivered.

yes , that dose sound more like it. its been a while since i ran kjet.

but you get where i'm comming from., my point is that i reckon that the engine may be flooding.

thanks very much as usual for your input too Paul, much appreciated :wink:

BUT….. i do have to admit, i am confused.

what do i need to buy or sort out?

are you both agreeing (Jamez and Paul) that the problem is now the WUR and not, the metering head?

if yes, how do i remove the WUR?

oh and by the way! how much voltage should the WUR be recieving from the plug that goes into it????????????????????

cheers lads! 8)

You don't even know if its running rich, lean, or if its ignition, or whether its isolated to cold or warm engine. Don't buy any parts yet!

Whereabout are you located?

paul_c said

You don't even know if its running rich, lean, or if its ignition, or whether its isolated to cold or warm engine. Don't buy any parts yet!

Whereabout are you located?

you have not checked co??????


what do the plugs look like after all these starting shenannegens

by the way, i have just been reminded to say that the car does not start well from cold either. it would never keep running by its own accord. whoever turns the key has to manually keep the idle at about 1400-1500 rpm, any lower and the car kills the revs and tries to cut out. after about a minute it starts to handle itself beforre then cutting out again after running hot!!! :cry:  :cry:  :cry:

EDIT FOR PAUL!!!!

paul_c said

You don't even know if its running rich, lean, or if its ignition, or whether its isolated to cold or warm engine. Don't buy any parts yet!

Whereabout are you located?

 sorry matey! didn't noticed yours or wooders replies till after i had added the above post!

i think it is running rich

i am in Boston, Lincolnshire :wink:

bren said

by the way, i have just been reminded to say that the car does not start well from cold either. it would never keep running by its own accord. whoever turns the key has to manually keep the idle at about 1400-1500 rpm, any lower and the car kills the revs and tries to cut out. after about a minute it starts to handle itself beforre then cutting out again after running hot!!! :cry:  :cry:  :cry:

EDIT FOR PAUL!!!!

paul_c said

You don't even know if its running rich, lean, or if its ignition, or whether its isolated to cold or warm engine. Don't buy any parts yet!

Whereabout are you located?

 sorry matey! didn't noticed yours or wooders replies till after i had added the above post!

i think it is running rich

i am in Boston, Lincolnshire :wink:

How do you know if its running rich, and by how much? Do you have a Gastester? You can buy and use a cheap (?100 or so) one, but they're not that great. You need to let them warm up for around an hour before you get meaningful readings. If a garage did the work, their (much more sophisticated) 4 gas analyser would also be able to measure HC, which would give a good indication of how the ignition system's doing.

paul_c said

How do you know if its running rich, and by how much? Do you have a Gastester? You can buy and use a cheap (?100 or so) one, but they're not that great. You need to let them warm up for around an hour before you get meaningful readings. If a garage did the work, their (much more sophisticated) 4 gas analyser would also be able to measure HC, which would give a good indication of how the ignition system's doing.

watcha matey!

no i dont have a gastester. i only said about it running rich due to the black ends on the spark plugs ops:  

i'll be honest with you, i live in a crappy area for garages and i simply dont trust any of them.

i really would prefer doing the work myself as much as possible. could i hire one of the ^^ more sophisticated gastesters?? what do you reckon matey???

thanks once again mate :wink:

bren said

paul_c said

How do you know if its running rich, and by how much? Do you have a Gastester? You can buy and use a cheap (?100 or so) one, but they're not that great. You need to let them warm up for around an hour before you get meaningful readings. If a garage did the work, their (much more sophisticated) 4 gas analyser would also be able to measure HC, which would give a good indication of how the ignition system's doing.

watcha matey!

no i dont have a gastester. i only said about it running rich due to the black ends on the spark plugs ops:  

i'll be honest with you, i live in a crappy area for garages and i simply dont trust any of them.

i really would prefer doing the work myself as much as possible. could i hire one of the ^^ more sophisticated gastesters?? what do you reckon matey???

thanks once again mate :wink:

I reckon someone local to you on this forum (unfortunately I'm not!) will kindly volunteer to look at the car for you. There's conflicting info above, and it really needs a fresh set of eyes and ears on it.

paul_c said

I reckon someone local to you on this forum (unfortunately I'm not!) will kindly volunteer to look at the car for you. There's conflicting info above, and it really needs a fresh set of eyes and ears on it.

i wish i could make it easier for you to know what the car is like.

i've uploaded another video of it after its been running for about 15mins. by now of course it has got up to temperature and the idle goes lumpy, the revs slowly die till eventually the car cuts out.

anyway rather than me bore you and keep going on heres the video :wink:

by the way, i cant remember if i've mentioned or asked about it alread but once the car runs hot the coil gets so hot you can barely touch it. is this supposed to happen????

i know after reading all 6 pages you must be thinking that i must be stupid not to have solved this yet but i am not a mechanically minded person in any way, shape or form and i dont pretend to be so i really am desperate to put this to rest now.

thanks

hi bren have you done the full injector test with all four injectors removed i did this test on sunday the results are quite revealing my number two injector delivered nearly twice as much fuel as the others and the spray patterns on all the injectors was completly wrong and two of them were dripping after turn off
 my car is behaving just like yours all the hot stalling and every thing have you opened the fuel filter on the metering head incoming side on mine was full of rust

adi262478 said

hi bren have you done the full injector test with all four injectors removed i did this test on sunday the results are quite revealing my number two injector delivered nearly twice as much fuel as the others and the spray patterns on all the injectors was completly wrong and two of them were dripping after turn off
 my car is behaving just like yours all the hot stalling and every thing have you opened the fuel filter on the metering head incoming side on mine was full of rust

watcha matey!!!

thanks for your input, i will do it tomorrow and check back with you then