Not totally sure what's at fault here, but I seem to have an intermittent missfire under load. The car bogs down and splutters.
But it is intermittent.
The first time it happened was back in February, I hadn't used the car much due to the snow. It was down to the dregs in the tank, so I the first place I drove it was down to the BP garage down the road and it was spluttering then.
Then I had a poor month in April, decided to leave the car in the garage for a few weeks as it's a bit thirsty. Got it out at the beginning of May, again with dregs in the tank, drove it to the garage and filled up. No drama. Drove it to work the next day and for the first two or three miles it was spluttering. Then it seemed to clear and it was fine (actually, it was bloody brilliant) for a month.
Being a bit of a nob, and very busy at work, I ran it down to fumes last Friday. It was fine, but there's no Shell garage near me so I wanted to fill up after work (there's one near the office). As I drove away from the office it was spluttering a bit, then on the way back to mine it was doing it really badly. Really smooth while cruising, but bogging down with no power when on boost. Which to my mind suggests a fueling issue?
Well to add complication to it, someone who moved my car at Mod Nats the weekend before had said my clutch needed adjusting so I thought I'd have a fiddle on Friday before driving to get fuel.
On Sunday I changed the fuel filter, assuming it was clogged.
Just been out for a spin and again, first few minutes it was spluttering quite badly. Idling beautifully though! So I stopped, wound the clutch back to where it was, roughly, and it seemed to be better afterwards. Actually, it seems fine.
So I'm wondering, is this an issue with fueling? And could it be as simple as having a load of shit at the bottom of my tank?
Or is it something more sinister, like a faulty component. I know it's not the lambda, as it didn't have one between October and mid April and the first couple of spluttering moments it was running without a lambda. Now it's got one, and it's doing the same.
Or could having a clutch not biting properly cause it to splutter a bit under load?
Hmm, another possibility, could it be an ignition problem?
There's a burble from the exhaust when it bogs down. Maybe it's unburnt fuel?
Mine does the exact same dude proper bogs down
sounds like yr problem alex is shit fuel either old or bottom of the tank
top it up, shake it about - hopefully it'll go away
I'll limp it to work tomorrow then, leave early just in case, put a bit more in and see what the score is.
The old girl's been running really well recently (as in, for the entire last year) so I'm gonna be gutted if she starts acting up.
Shit scared of piston meltage, not a club I can afford to join!
I'd vote for ignition issue, despite the running on fumes references. Have a look/replace plugs, rotor arm and dizzy cap?
Solved my 'spluttering' recently...
Clutch bit a red herring I reckon.
How are your earths? make sure the one from the coil to the gbox is strong.
I've had similar symptoms which I fixed by making 3 earth points, the one mentioned above, then I made one from the earth point on the inlet manif to the bulkhead, and one from the cylinder head to the o/s suspension turret.
Worth a go!
All my earth straps are new, and greased to avoid rust setting in.
Rotor arm and dizzy cap are fairly new too - Geniune VAG and only a year or so old.
Where's the cheapest place to get W5DPOs?
GSF probably, though people have generally used ngk and they are half the price! £20 a set delivered on ebay.
It's running NGKs at the moment
Bit of an update today, drove the car to DC10 and back. Or rather, limped.
I wanted to see if it'd get better with use, and tbh while it's been worse it's really not happy.
It's shuddering on part throttle and bogging down intermittently on full throttle (or under heavy load), makes a bub-bub-bub noise from the exhaust when it does so.
Thinking it may not be the fuel (I topped up with half a tank of BP Ultimate on the way back, which made no difference) but not sure what it could be.
I bought Quantum leads at BVF last year so I'll replace those tomorrow, see what it does. I'll check the spark plugs, dizzy cap and rotor arm too.
But if it's not the fuel and not the ignition system, what could this be?
Swap the fuel pump relay and see if it goes better. This relay is the same on all mk3's, easy enough trial :)
Hmm yeah scrap yard trip tomorrow then :)
Quote from: Alex on June 13, 2010, 06:12:37 PM
Bit of an update today, drove the car to DC10 and back. Or rather, limped.
I wanted to see if it'd get better with use, and tbh while it's been worse it's really not happy.
It's shuddering on part throttle and bogging down intermittently on full throttle (or under heavy load), makes a bub-bub-bub noise from the exhaust when it does so.
Thinking it may not be the fuel (I topped up with half a tank of BP Ultimate on the way back, which made no difference) but not sure what it could be.
I bought Quantum leads at BVF last year so I'll replace those tomorrow, see what it does. I'll check the spark plugs, dizzy cap and rotor arm too.
But if it's not the fuel and not the ignition system, what could this be?
Try unplugging the lambda while its idleing? mine was a bit like that when it happened on mine. 30 second job would find a solution or rule it out!
Tried that earlier :(
What's the ignition system health like- mainly hall sender and coil.
Coil pack was replaced just before the conversion, and I think the leads are the same ones I bought when I swapped the engine. Done roughly 32k miles. Plugs about 25.
Hall sender's an unknown, how much are they to replace?
First port of call is the leads, I think. Be rude not to, seeing as I have three sets in the garage. :)
i'd change plug leads rotor arm and dizzy cap if you have them around plugs also as they are supposed to last about 20,000 miles.
Hall senders tend to be a bit all or nothing in my opinion.
I've had intermittent hall senders, depends on how they're failing. Deffo do the leads if they've been on there since we dropped that G40 lump in.
Well it's not missfiring any more, fucking thing now doesn't start. ::)
Changed plugs, leads, dizzy cap and rotor arm.
It turns over but doesn't fire, and stinks of petrol. So I'm guessing I've got something wrong.
http://www.youtube.com/watch?v=vAtIYu0nbEA
I should never be let loose under the bonnet. :(
You got the firing order right?
That's what I'm thinking now. Tried swapping the king lead, dizzy cap and rotor arm back to the old ones and no difference.
Anyone got a diagram showing the firing order?
Firing order checked from here:
http://www.polog40.co.uk/forum/index.php/topic,2212.0.html
And it's right.
hmm, looks like next step is checking leads
Unplugged each lead in turn, rested it on the rad cover with an old spark plug. No spark from any of them.
Do I need the little screw-on bits that come with the plugs? The old Beru leads didn't. :-\
Random. Just been out to try a plug with an old lead, turned it over and it fired up with only three of the new plugs in.
Turned it off, plugged the lead back in and it started up first time.
Strange.
But, hey, just when I thought I was out of the frying pan.
Took it out for a spin and it's ticking. Seems to drive ok, though I didn't take it far. It's making a loud ticking noise that varies with the revs. And though it drives smoothly there's an intermittent drop in revs when it's idling. Wasn't doing that on Sunday, it's a new one for tonight. Here's a video.
http://www.youtube.com/watch?v=CIMM_JAvJVM
Any ideas?
Getting a bit fucked off with this now. The car was FINE two weeks ago for fuck's sake. ::)
A bit of extra info - sounds like it's coming from the top of the engine. I guess it could be a really noisy injector, but I doubt it.
Quick flick around the net and I'm thinking it's a sticky valve or possibly a sticky tappet.
Tappets were changed at PSD about 20,000 miles ago.
Whatever it is though, it's just started. Reckon it's to do with repeated cranking this evening?
In the past I've found ticking noises to be a spark from an ignition lead or connection that's grounding before it reaches the spark plug. New leads or at least a good wiggle of the old ones helped for me. Not sure if you've already done this or not though with all the troubleshooting you've done so far.
Is the plastic cover inside the dizzy that protects the hall sender wiring still there and intact? I've had these go brittle and fall apart - meaning intermittent missfires, occasional refusal to start etc. Worth checking.
Is it a ticking noise and not a spark arcing kind of noise? Wait 'til it's dark and try it again - you'll soon notice if it's arcing out somewhere!
Have you got a spare dizzy you could try?
Sounds like a ticking at the top of the engine - even under the rocker cover. Not really sure. If I put my head under the bonnet I can hear the engine, the charger, ticking injectors and whatever this noise is, so it's quite difficult to pinpoint.
Don't have a spare dizzy to try either. :(
The plastic cover in mine seems fine - is there a specific way that it mounts? Should it clio into anything or does the dizzy cap hold it in place. Mine's loose.
Where are you located Alex? I've a known working dizzy, leads, rocker arm and cap on my daily (GT, same dizzy). If you're close I don't mind troubleshooting with you.
Must've been having a wood for the trees moment last night, plug 4 wasn't on properly. Never work on a car when tired.
Ticking noise is now gone and the car seems ok at the moment, but it's still spluttering a bit at full load and low revs. Definitely not as bad as it was on Sunday.
Gonna go down to a meet in Peterborough to see how it is. Still hoping this is a shit fuel issue. :-[
I'm in Stamford by the way...
im not far away if you need to borrow anything ;)
Thanks guys :)
Took it down to Peterborough and back (30 miles, ish) and it's pretty much ok. Getting a bar of boost, and it's taking off down the road well. Still kicking a bit under constant throttle though, and sometimes it's burbling and bogging down under full throttle. It's idling fine.
Bit of a dilemma really, I wanted to take it back to Cardiff on Friday as I'm off to see my folks. Three and a half hours of missfiring G40 will steadily erode my sanity, but I'm trying to decide whether to just take it and run the tank down again so it's completely full of fresh fuel.
Trouble is, I'm taking Caroline. She won't be amused if we break down.
The noise it's making sounds like a burble, like a Subaru exhaust note but sped up and higher pitched, if that makes any sense. Unburnt fuel coming out of the exhaust perhaps?
So is it running rich maybe? Would that make it bog down? Could it just need a tune up?
Or am I being optimistic...
I'm down to dizzy and coil pack if I'm replacing ignition parts.
If it's fueling, would a dying CO pot cause it to burble and bog down?
do you run an Air fuel ratio meter? if so - whats that saying?
could be the coil you know - i've known newish ones go a bit shit!
Plugged it in and it says it's running fully rich, but then you never can fully trust a Duostyling AFRM. ::)
That said, it was working before the last lambda broke last year. So who knows. :-\
I'd prefer it to be a coil issue than a dizzy issue. It's a cheaper fix.
if its running well rich - could be overfuelling and you could have a shit lambda probe. where was the probe from?
Lambda is ignored at WOT...
Christ I'd never have one of those duostyling guages near my car again. Shame really as they were a brilliant solution.
Lambda is second hand from here, did try unplugging it on Sunday and still had the same problem, don't reckon that's at fault but it was fitted a week or so before it started acting up.
And yeah this is my third Duostyling gauge. But again, doesn't seem to matter if it's plugged in or not. I've started running it since the problems started, and tried unplugging it on Sunday.
Need a neat place to fit a wideband, or a neat wideband display (a square one)
Quote from: Yoof on June 16, 2010, 10:34:05 PM
Lambda is ignored at WOT...
true - but it dont appear to be working - unless the gauge is shit (which they are)
i'd try another coil
Think I might try just buying a coil and dizzy. Stick it on the credit card and worry about it later.
TBH it's the time of year where I want to be using the Polo every day. I drove the Passat back to Cardiff on the weekend and missed the G40 all the way. At the moment it's just sat in my garage doing nothing :(
Likelihood of it being ignition related...? Personally I reckon it's dumping unburnt fuel out of the exhaust, hence the burble. If it was running really lean would that make a different noise?
there was a bloke selling pattern dizzys on ebay for about £50 delivered - no idea of the quality mind..
I have a spare g40 dizzy if you wanted to buy...
How much, and does it definitely work?
EDIT - sorry that makes it sound like I'm expecting you to rip me off, I know you're not... :D
Just called GSF - they do three different coil packs for the G40. A basic unbranded one for £25, something in the middle (Beru probably) for £36 and Bosch at the top for £45.
But they don't sell distributors. That means getting my ass raped at the stealers if I want new.
Hit me Pete, what are you after for the dizzy and what sort of condition is it in?
it is on a running car now... if you wanted me to run it on my car and time it up and use it for a week - i can do!
make me an offer mate!
search coils on ebay and ask them the brand - quite a few on and berus will be fine
Think it's on a Beru one at the moment, think I'm gonna change the dizzy first though because it's more of an unknown. For all I know it may still be the factory one, don't know if it's ever been changed. Coil I know is five years old.
Got no idea what a G40 dizzy is worth without calling a parts department - let me know what you want for it. I'll pay decent prices for it, I'm not out to drive a hard bargain. Just want the bloody car working again.
And there's more.
Bought a dizzy from Pete Mirfin (tried and tested, and fine) which arrived on Friday. Just finished fitting it.
The car wouldn't start at all this morning, again. Turned over but wouldn't fire up. Changed the dizzy and it spring back into life straight away.
It's running smoother and will now cruise at speed, but I can't go more than about half throttle without it bogging down and juddering like it was before.
Which I guess leaves the coil pack?
I'm going to change that tomorrow, tipping the spendometer at just over £150. If that doesn't work I'm not sure what to do.
Starting to wonder if the coil and dizzy were both faulty. It's definitely healthier on the new one.
So yeah, no longer an intermittent missfire under load. It's now a constant missfire under load. Every time.
Which is great timing. Caroline's car failed its MOT last week and we've SORNed it, so she's using the Passat to get to work. Which leaves me with the Polo and whatever cars we've got in at work. Our RS Clio long termer went back to Renault three weeks ago, our Kia Soul has a flat tyre (new wheels and tyres arriving this week) and our Toyota Yaris is a track car (which currently has no expansion tank, so that's not suitable for the commute to work either).
So unbelievably, despite having an abundance of cars none of the fuckers work! ::)
Did you set the ignition timing properly with the new dizzy?
Constant missfire under load does sound a lot like the coil breaking down (or possibly leads/plugs), but as you've changed the dizzy I'd make sure you've setup that properly too.
I didn't do it, Nick did. But by properly, how do you mean?
Coil pack is the only constant in all of this, fingers are all starting to point in that direction.
Am sure Nick'll have done it right! Just read like you'd just bolted the dizzy on without doing the timing.
Yeah we based it on the old one then fine tuned it. Trust Nick to do it right more than most garages but didn't know if there was anything weird we needed to so beforehand.
GSF have three coil packs in stock.
Unbranded at £26
Beru at £36
Genuine at £45
All three are in stock, so I can collect on my lunch break. Win.
Thinking probably going to go for Beru - it's good quality stuff from experience so far.
Or do you reckon it's worth going for genuine stuff?
Opinions?
I went for the unbranded iirc. I compared a BOSCH and the unbranded side by side and they looked identical, even down to the casting and molding marks.
It's been good for over a year so far. Up to you for the sake of £10 it may be worth getting the BERU. At the time I bought mine I think the only choices available were unbranded and BOSCH and the BOSCH was more expensive than the 'genuine' one is now.
genuine may be beru! but in a different box!
although valeo was oem IIRC
Just reading up on your thread and we were currently having the same problem as you are with an cossie which me and my mate just bought, we tracked it down to ignition fault, but after changing the dizzy and coilpack, leads etc (which did improve it a lot) it was still the same spluttering under load, we ended up throwing towel in and took it to a rolling road for tuning. They instantly said the fuel pump was knakd.
This is where we are at the moment so ill post tomorrow when I've fitted the new one to let u know if there's any improvement.
Cheers Tom
So sick of the arseache I ended up buying genuine - came in a V-Dub box and everything.
Fitted it in the car park at work and I'm happy to say that (so far, at least) it's absolutely fine. Took it out for a spin and it's 8)
Which makes me a happy boy!
Will update you once it's had a few days of normal use though, just so this topic can be used as a reference point.
High Five!
Glad you got it sorted (touch wood!)
£180 lighter for the privilege though, which isn't ideal. Thank god for credit cards...
what did you buy, an ignition coil?
And the rest!
Coil, dizzy, W5DP0 x4, dizzy cap and rotor arm. Picked up the Quantum HT leads at BVF last year. Gave Nick 20 to fit the dizzy.
Even with GSF discount that's not cheap! :-(
But so far so good. I changed the coil just before the conversion five years ago and it's always had a slight missfire around 2k rpm. That now sems to have gone.
Gonna see how it behaves for a few days before I celebrate tho!
this is very very similar to mine, ive changed everything you have except the whole dizzy, im starting to think its the hall sender, seriously doing my head in, its my daily so very annoying
always nice when you solve a problem i have loads of spare old coil packs and leads and stuff witch helps to fix faults with out spending money on replacing parts that don't need replacing!
Happy times still, I should add. It's been a fun week of commutes! :D
Doesn't feel as sharp as it should though, so I reckon the timing needs a tweak. It's not pinking so I assume it wants a little more advance and it should be fine. I'll have a tinker after work next week, just haven't had time yet.
But generally it's really really smooth to drive, which is nice. I'd quite like to get it in for a session of rolling road tuning at some point soon, which I might do the week of the Polo Show if I get time.