Missfire on startup, taking the piss out of me.

[tim15888]

I'm actually getting a bit ££££ed off at this fault now. I've never failed at fixing anything in my 23 years but this is turning out to be a bit of a head banger.

Basically, what my me7 1999 t5 is doing, missfiring on start-up for the first 20-30 seconds or so. Badly enough to put the engine management light on via the lamba sensing the missfire and coming up with a random missfire code. (not a dodgey coil code or that would come up with the cylinder number, like when my no2 coil went yesterday!). Once the missfire is gone, the engine is perfect. No power loss or anything in the 186k she's done.

Things I have tried are: (lukily I have a friend who breaks Volvoids so anything he's got, he lets me borrow to rule it out)

New plugs
Replaced the coils
Air temp sensor
Maf sensor
Lamba sensor (Front)
Engine temp sensor
Map sensor

Sure there's a couple of other bits and bobs, most of which I have changed whilst clutching straws. Scince the fault started, I've also had a re-map by Hamish at HLM, and at the same time he also did a Volvo update where the throttle body I fitted in the summer was married up to the ECU propperly. Totally unrelated but I've also given the shagger an oil change + flush with some of Castrols finest Magnatec about 500 miles ago, and the oil is still clean enough to cook your chips in.

Whilst she was missfireing this morning, I tried unplugging injectors one by one to try and suss out which cylinder the missfire is occuring on the old fashoned way, as the code reader doesn't tell me this as it isn't a coil fault, so can only sense the missfire at the lamba sensor. This told me that the missfire seems to be on cylinder 2.

Other things I am going to try are, re-fit the throttle body with some gasket sealer to make sure there is no slight air leak, pretty sure there isn't because it would idle high, and also would have a boost leak if this was the case. When I get some, I am also going to try changing injector 2 to make sure it isn't dribbleling when it's cold. Also unlikely, once again grasping at them pesky straws. If anyone has a spare injector, or a spare set I would be greatful if you could sort me out with some. Mine are the light blue ones.

I'm sure that I have missed some things off this post, but Top Gear has just started and I like Top Queer, so I want to watch it.

Any help on this would be great, and much appreciated, so I look forward to the replys.

Thanks in advace, Tim.

[bigrotch]

I had a misfire issue a while ago and went through the lot as u have and it ended up being flywheel/crAnksensor soon as I replaced that it was spot on.. It come so close to gettn scraped cos of it new cost about £20 job done

[tim15888]

Did it do it all the time or just when you start it from cold? If mine was doing it all the time, the crank/cam sensors are something I would have looked into but it's only on a cold start this one unfortunately... Yours looks a nice one actually in that signature, not selling it are you? A bit fallen out with mine now, might go BMW 740/540 or a Clio 172... Must sort this problem on mine first though.

[bigrotch]

Unfortunately it was all the time sometimes straightaway sometime only when hot it was a rite painin the arse.,, what injectors you I got a spare set of oranges u can try mate ... Don't sell stay with it

[bigrotch]

Think u got whites mate

[tim15888]

One down from the biggest. Light blues mine mate. Nearly bought a set of whites the other day, but would have needed to get the map altered to suit... Should have got a set before I had it done.

[bigrotch]

Oooooherrrr sir blues mmmmm that's what I'll prob have to get when I set up my kkk k24 turbo lol oh and remap... What about exshaust manifold s
Gasket or manifold gasket. Could spray
Carb cleaner on it when running if it runs up u know u got a leak some wear as u said mate

[tim15888]

Yea, good trick that. Use it on bike inlet trumpets all the time but keep forgetting to pick a tin of brake cleaner up lol. I'm pretty sure that isn't the problem though too be honest, just another way to waste a bit of time haha.

[deathrider311271]

One down from the biggest. Light blues mine mate. Nearly bought a set of whites the other day, but would have needed to get the map altered to suit... Should have got a set before I had it done.

why would you want to install whites when you already have a higher flowing injector already (blues)???

[deathrider311271]

As for your problem of misfire when cold, have u had a compression test done?
What code reader are u using? mine gives me a code and cylinder as soon as it starts misfiring

[tim15888]

Thought whites were biggest? Anyway, not compression issue. Rolling roaded at 236bhp out of 240 before the map when running standard... My scanner is a MAC tools one, does tell me which cylinder it is if it's a down coil. If it's just not firing for some reason non-electrical, like duff valve seat or leaky injector etc, readers get info from the ECU and any reader will come up with a random missfire when it picks it up at the lamba instead cos' that's all the ECU knows...

[deathrider311271]

Thought whites were biggest? Anyway, not compression issue. Rolling roaded at 236bhp out of 240 before the map when running standard... My scanner is a MAC tools one, does tell me which cylinder it is if it's a down coil. If it's just not firing for some reason non-electrical, like duff valve seat or leaky injector etc, readers get info from the ECU and any reader will come up with a random missfire when it picks it up at the lamba instead cos' that's all the ECU knows...

injectors white used in V70 t5s early models
Blues used in later T5s and earlier V70R
Greens are the biggest used on later Rs and some T5s i believe dont come up that often

[deathrider311271]

i know u have changed coil packs, have u tried moving number 2 coil pack for another one too see if the problem moves?

As u said it could be the injector itself, i would try swapping it to another position again to see if the problem moves

[tim15888]

Yep, was planning on doing that today if my mate didn't have a set of injectors I can borrow. On another note, I put some Brisk plugs in not too long ago, gap is huge on them and is working the coils hard. They are coming out today as scince putting them in the other day, 2 coils have blown.

[tim15888]

Think I've found the problem. The missfire is on no2 cylinder,... think the injector is slowly leaking from the rail over night and putting excess fuel in the cylinder. It's one theory ayway. Now to find a blue injector to throw in. No-one got a spare have they?

[bigrotch]

Be easier to get them tested and cleaned a company on eBay quoted todo all 5 of my whites £65 delivered back tome etc

[T5frankie]

Be easier to get them tested and cleaned a company on eBay quoted todo all 5 of my whites £65 delivered back tome etc

there is a bloke on here that does it mate jimathan

http://www.vpcuk.org/forums/showthread.php?t=15818

[bigrotch]

there is a bloke on here that does it mate jimathan

http://www.vpcuk.org/forums/showthread.php?t=15818

He's not doing it any more frankie I went to him first ofall mate

[tim15888]

injectors white used in V70 t5s early models
Blues used in later T5s and earlier V70R
Greens are the biggest used on later Rs and some T5s i believe dont come up that often

Just clarifying which are the biggest, I was positive it was whites. Green = LPT, Orange = non-turbo, Blue = me7 t5?

[T5frankie]

Just clarifying which are the biggest, I was positive it was whites. Green = LPT, Orange = non-turbo, Blue = me7 t5?

totally wrong

850 t5 orange smallest
850r v70r whites
me7 t5 blues
s60r greens largest