erratic idle / cutting out

[adamm306]

Hi guys instead of spamming my project thread its probably easier to have its own dedicated thread

having a bit of trouble with the xud.

everything was running fine and tip untill today.

Basically it struggles to idle and i can feel slight missfires and hesitation below 2k RPM

when the cars first started it will sit nicely at 1000 rpm for 10-20 seconds or so then drop down to 500 to the point where its going to cut out does this for around 10 seconds or so then raises back upto 1000 so on and so forth.

once you get going onto boost or over 2k rpm the car is fine (poodling along at 25-30 in 4th/5th car misfires and has general hesitation if you let off throttle)

car completely cuts out if your driving along and slowing down to change gear dump clutch itll cut out and as u bring it back up for the gear change itll bump back into life.

oh and after i switched the car off fuel started leaking from the vent point of the entry so it had me thinking an air leak or some sort?



how can i test for leaks anyone got some anti-retard guide to check for leaks?

so far ive looked at leak off pipes and boost compensator both seem fine.

any help appreciated i am a bit of a noob when it comes to things like this.

thanks

[Tom]

Thats bloody weird, issues wih fuel get worse as you put your foot down and demand more from it. All i can suggest is have a good look over all your fuel pipes, should be an obvious problem really.

[adamm306]

yeah it is strange mate is it possible it could be the injectors? would explain the missfiring

[Tom]

Yeah it could be, a video of it idling would be of help to some of the people that have seen loads of these with running issues, you could always crack off injector lines one at a time whilst its running and see if it gets worse or stays the same.

[powerandtorque]

I've seen similar symptoms from an air leak on the fuel feed side - fine under load with the revs up, intermittently hestitating on light throttle cruise, not at all happy after coming off the throttle nor at idle, often cutting out and needing re-priming to allow it to start again.

It wasn't my car and I didn't do the repair so I can't confirm exactly what the issue was, but certainly you could see air bubbles in the fuel line at idle and I know that a badly perished rubber fuel hose was at least part of the problem. Best guess from what I know is that the engine movement as you came on and off the power was in turn moving the fuel pipe and allowing air to enter the fuel lines.

It was Paul_13 on here's 205 NAD so he might be able to offer more insight on what the eventual problem(s) were - I was just the poor sod doing him a favour driving it 50 miles back to his house...

[Mattcheese31]

Sounds like an air ingress issue, check round the bottom of the fuel filter housing :-)

[adamm306]

thanks for the replies guys

to test air leaks do i get some soapy water around the filter housing?

[Mattcheese31]

thanks for the replies guys

to test air leaks do i get some soapy water around the filter housing?

squeeze the primer bulb until hard and then hold it tight while you look for leaks . .

[adamm306]

no worries man ill take a look tomorrow on my lunch break

with the engine off i presume? haha

[Tom]

Yeah, you need to listen for air hissing or fluid bubbling etc, you need it to be quiet really :/

[adamm306]

lol thanks, go easy on me im a noob with engines ill report back tomorrow with the outcome and video..

[adamm306]

Didn't get a chance to get a video on the way to work this morning but it seems to sorted itself out a bit with the idle?

doesnt seem to be as bad now but ive noticed missfiring higher up in the range from 3.5k-4k

ive changed the filter and stuff beginning to believe it could be an injector

[Tom]

You want to by pass the stock fuel filter housing imo, i just happen to be selling some filters

[adamm306]

got any pics of the filters? i was thinking about bypassing it just for piece of mind anyway.

its strange it doesnt seem to have any issues when it first starts up in the morning its once the car gets warm these problems start appearing

[adamm306]

Typical. I go out to get a vid and test it and now the car is running fine? Took it for a good thrash and now it's not doing it anymore just the very occasional misfire strange

[adamm306]

[adamm306]

Right... replaced the broken leak off pipe today

Didn't bleed the injectors after I did though does that matter??

seems the problem is still there kinda pissing me off now

took a video if it idling today cant really hear it or see it struggling to much from the vid so ive noted the key points

http://www.youtube.com/watch?v=o6UnJRG2C...4-overview

00:32-0:44 - starts to struggle
0:45 - missfire
1:05 - idle starts to raise on its own
1:24 - drops off and starts to struggle
1:42 - starts to raise up again


Whats your verdict? I know its a shit vid but any help is appreciated... i still believe it could be a dodgy injector

always seems to struggle after you give it a rev aswell as seen in vid

[Teddy]

Injector sticking ?

[adamm306]

that's what im thinkin mate just wanted a second opinion before i rip em out

[Tom]

What the f*ck is that loud metallic tapping?

[adamm306]

that seems to be under investigation at the moment. seems to come and go but lots of stuff is leaning on bits of the engine and moving/pushing stuff makes certain noises go away

any idea on the idle? doesnt do it when you first start the car in the morning only when it warms up runs like a sack of shit for a bit after you give it a hard rev in neutral?

[Tom]

So does it do this with the engine warm or is it just when you first start it?

[adamm306]

been out in again on my lunch

first thing in the morning when the car is fresh and cold it doesnt seem to do it once the car warms up a little bit after 5 minutes it starts struggling to idle after you give it throttle

i've found if you pump the grenade whilst its running and give it some throttle it dosent seem to bog down after seems to be idling nicely.

there is no visable air bubbles in the fuel line although when you switch the motor off you see a few big ones (i dunno if this is normal)

is the grenade supposed to stay rock solid whilst the motor is running?

the occasional missfire on idle is followed by a puff of blue smoke so could be a duff injector

ive replaced the leak off pipes is it essential to bleed the injectors after? i didn't do this

thanks for trying to help me its really frustrating me at the moment

[adamm306]

bump...

[Tom]

Grenade is normally squeezable when runnining because the pump is sucking fuel through it. How good are your glow plugs? Im half tempted to say its something electrical, loads up the alternator then the revs drop off. Dont need to bleed injectors after replacing the leak offs.

[adamm306]

an electric problem on a xud..?

i've only had the thing a bloody week and im sick to death of it

[Tom]

Thats what xuds do, when they work well, they're fantastic, then they dont work right up until your fed up, then once you've had enough it'll work again for a while.

What fuel are you running? Just diesel? Something has to be happening to effect the revs, pumps dont just do it for no reason.

[adamm306]

just straight diesel mate

it was literally working fine then i woke up one morning and it started doing this

if you just leave it to idle its fine its after you apply any throttle to it. it refuses to sit back at idle properly and will just cut out

was driving along earlier at like 40mph and it just hesitates and doesnt go anywhere when you put the throttle down then itll kick back in violently and missfire

it doesnt even hardly smoke anymore either its weird

[adamm306]

completely shat itself earlier felt like it was running on 3 cylinders with white smoke bellowing out the back.. unburnt fuel..? injector?

[Tom]

Not a hole in the block is there? lol