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General => The garage => Topic started by: davidhawkins_78 on 24 September 2004, 09:31

Title: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 24 September 2004, 09:31
Read this through first ...

http://www.golfgtiforum.co.uk/index.php?topic=13065.0

After some cleaning and trial and error the ISV and coolant temp sensor can be ruled out i think, and the problem is still happening with them both unplugged!

So just to recap - no bouncing revs, but erratic loss of power and mis-fire (spluttering) at what seems to be various throttle positions and revs. Beating the throttle doesn't seem to solve it, but eventually it 'clears' ??

Seeing as the revs aren't bouncing about (I can't say I've checked this, but I'd thin I'd notice the rev countered on a mission!), I'm not sure it's dizzy / hall sender related - I'm thinking MAF (Mass Airflow Sensor) ... seem sensible ???

I've read people taking these apart and cleaning them - is it easy??

Also with having electrical testing equipment is there a way to test it to show it's faulty. I'm just loathed to go round the houses replacing way to many parts and spending a fortune !!

Cheers for any help

 ;D ;D ;D
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: topher on 24 September 2004, 09:44
Completely different car i know, but what you describe is exactly the same as what mine was doing, and was indeed a faulty MAF sensor.
Cleaning them is easy (although i finally had to replace mine) , just use carb cleaner, probably dont even have to take the sensor out of the housing to do it, i didnt !

Chris.
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 24 September 2004, 09:51
I like the sounds of that !!!  ;D

I must say if it is that, i'll probably have to replace it as you did - but after just getting my design 90's this month I hadn't planned on forking out for more parts !!

Carb cleaner and toothbrush it is - Topher, how long did u manage before you had to shell out ??
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: topher on 24 September 2004, 10:03
worked for about 2 weeks, then got stung with the ?250 bill for a replacement  :'(
not sure if it applies to mk2 parts but vw offer maf exchanges on mk4's for about ?75 now, they introduced this scheme 2 months after mine went. How convenient  ;D  >:(
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 24 September 2004, 10:06
'Awesome' do new units for ?99 - alot less than the ?290 rrp.

I still have this nagging feeling that i'll shell out for it and it'll not fix it - I had nigglin problems like this !!

Cheers for the help topher :)
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Blue MK2 on 24 September 2004, 10:33
Is the mass air sensor on the airbox?

If you need that or the dizzy then ive got them for you Dave ;)
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 24 September 2004, 10:35
Cheers Blue - you got a spares shop going you're keeping quiet  ;D
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Blue MK2 on 24 September 2004, 10:39
Cheers Blue - you got a spares shop going you're keeping quiet? ;D

 ;)

I took the cover off the airsensor box and gave it a clean with WD40. Just dont take the spring off or your car will run even worse. It did run better after cleaning but i dont think this will solve your problem.

Probably Dizzy/sparks/leads related.

I had this problem a few months back and the garage didnt even know what was wrong with it. One day it just started and they handed it back to me and now ive got lots of spares? :P

I even changed the ECU and ignition moduel which sits ontop of the ECU. Might be worth checking
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 24 September 2004, 11:26
So in the end it was a drop it off at the garage job and you get a large bill eh blue ... ???

Didn't you ask what the source of the problem was in the end ??
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Veedubgt18v on 24 September 2004, 18:35
mine does this particularly in fourth and fifth gear, i reset the timing, make sure its all good and done with the blue sensor disconnected and at 2000rpm. i then took the cover off the maf and cleaned the tracks inside, it made no difference. so i moved the spring mechanism round 1 notch (you will see what i mean when you open the maf up) and it still does it just a lot less now. i think my maf is on the blink. so i will follow this post.
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 25 September 2004, 15:01
Right - after cleaning a few thinks just to rule them out - replacement coolant temp sensor / cleaning the tracks on the MAF and carb cleaner on the air temp sensor the problem is better - but still present.

Seem to be a definate part of the rev range (around 4 grand) that the misfire occurs, so look like the MAF is on it's way out.

When it stop raining I'll be having a look at the MAF with the engine running ... shame I can't easily find a spare to help with testing.

I'll keep you all posted  ;)
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Veedubgt18v on 26 September 2004, 09:13
thats exactly what mine is like, motorway speeds  >:( i can make it so that it only does it randlonly not everytime i use fifth gear! but i cant get rid of it, i have to be really careful how i accelerate in fifth gear!
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 04 October 2004, 15:04
Right - managed to get may hands on a second hand MAF that I've seen working properly on another GTI.

I'm gonna replace the air box / MAF / and all the pipes around the ISV and see what's what after. Looks like a nice game of elimination really, but seeing as the MAF, air box etc cost me ?20 I'm not too fussed.

Hopefully this will cure it and I can sleep better if I spend ?99 upwards on a new MAF, I'd go spare if I forked out for that and it didn't solve the problem !!

I'll keep you all posted ....
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 11 October 2004, 09:23
Update for you all ....

New MAF / New air filter / New pipework to throttle body & ISV / Cleaned ISV / New Temperature Sensor / Oil & Filter Change / New Dizzy cap & rotor arm / New HT Leads / New Plugs ... and she's still fecking misfiring !!

I suppose next is the coil and dizzy / hall sender. With mine being a digifant I bet I can't change the hall sender on it own ?  ???
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 12 October 2004, 08:44
New coil fitted last night and still no better  ???

Getting frustrated now  :'(
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Veedubgt18v on 12 October 2004, 09:38
injectors, fueling? timing? sticking valves i dunno its a bit wierd  >:(
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 12 October 2004, 10:02
Looks like she needs a run on a fault reader - anyone ever had to pay for this before ???
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Veedubgt18v on 12 October 2004, 10:19
nah i havent, can you do this on the digi?  ???
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 12 October 2004, 10:47
I hope so !!!

If not it's a multimeter job ... boooooo
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: ...joe on 12 October 2004, 11:40
dave, if you want to get in touch with me i know a guy in rustington who was a vw technician for about 15years and he now has his own company, he specialises in corrado's mainly but he might be worth a visit as he's only down the road. he's done some amazing work in the past so he might be able to sus whats going on. he has all sorts of diagnostic equipment and MOT testing stuff. if you get in touch i'm going round there tonight to work on a corrado so could ask him if you want. you'll have to pay him for the privilage but could stop the frustration? he works, monday wednesday and friday evenings as well so you don't have to take time off work!
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Veedubgt18v on 12 October 2004, 12:00
hey david look on this site under how to under the idle bit it tells you what readings you should be getting from your maf on what terminals dunno if it helps

http://www.thepaty.plus.com/8v/
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 12 October 2004, 12:57
Cheers for the replies guys ... might have to add throttle positions sensors and knock sensors to the list now !!

GTIJoe - you've got a PM :)
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Doug Mk2 on 12 October 2004, 13:19
sounds really stupid but my 8v digi did that until I changed the petrol to optimax.

What fuel are you using?

After a massive bill for changing loads of bits under the engine it turns out all I needed to do was run 98ron petro instead of normal unleaded!
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 12 October 2004, 13:20
Cheers for the reply Doug, but I've been going out of my way and paying well over the odds to ensure she runs on nothing else for the last year since I got her  ;D

Thanks for the reply though matey ...
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: Blue MK2 on 12 October 2004, 16:15
I hope so !!!

If not it's a multimeter job ... boooooo

This brings back memories  ::)
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 12 October 2004, 16:22
Lol .. don't say that Blue !!!

At least I love my Golf to bits, I can see how people lose their rag and just label them incorrectly as unreliable.

I'd rather have a few 'issues' than the car end up heading for the scrappy if it was say a Ford.

Blue - any chance you could have a word with whoever fixed your car and ask what parts they ended up changing ??
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: jimbo on 12 October 2004, 21:17
New coil fitted last night and still no better ???

Getting frustrated now :'(

bugger thats what i was going to suggest. ???  i had a problem a bit like yours and it turned out to be the coil. have you check all of your wiring loom to make sure that there are no chafed wires earthing out to the chassis?
Title: Re: Misfiring Mk2 - Help a mod in need !!
Post by: davidhawkins_78 on 13 October 2004, 11:12
There's no obvious broken wires - had a good check too !

Cheers for all the input though guys - keep it coming !!!  ;D