Coilpack?

[bigbluec 0]

Hi Guys I've done a lot of searching and delving throught the archives but can't seem to find a definitive problem or set of symptoms the same as i have with my 94 Vr.

 

Full story goes...

Car was left sitting around for a fortnight and when i got back to it, it had developed a misfire at low revs 1100 - 1900 rpm range + occasionaly on tickover.

Initially i put it down to possible damp but after checking it was dry and all was clean it continued so i replaced the plugs which seemed to make it worse as it then developed what i can only describe as a soft limiter off and on between 4500 - 6000rpm (was trying to go but was being held back then would pick up like a rocket etc)

 

So i started changing the plugs back but no joy, low and high misfire have remained!

The ht leads are all in good nick (less than a year old and definitely clipped on properly this time :oops: ) there is no arcing in the dark even with water mist and coilpack seems to be in one piece???

 

Does this sound like coilpack breaking down?

 

Please help before i go bald!

[mattkh 0]

Hi

 

Disconnect the electrical connector to the MAF and spray Maplins switch cleaner to both ends. Allow to dry. Reconnect.

 

Worth a try.

[diggerbucket 0]

Blue temp sender possibly.

[bigbluec 0]

Blue temp sender possibly.

 

How does this come into the equation?

[diggerbucket 0]

Just going by a problem I had with mine. It started getting lumpy at idle and hesitant when on throttle, but only occasionally and at any point in the rev range. For a start it was very occasional but it got worse over time, to the point it was hesitant and jumpy nearly every time I pushed the throttle, and it would cut out at idle sometimes.

 

New blue temp sender fixed it, it's only a tenner or so :)

[craigowl 0]

No arcing with sprayed coilpack should mean its probably OK, IMO.

[bigbluec 0]

No arcing with sprayed coilpack should mean its probably OK, IMO.

 

Well that's what i was hoping but i just can't figure this out all plugs are giving what i'd call healthy looking sparks and evenly but something is causing it to miss and i wondered if any of the above symptoms were indicative of an internal slow failure?

 

Still don't really understand how the blue temp sensor can effect this but i have just tried running it disconnected and it made no difference? :mad:

[diggerbucket 0]

Well that's me out of ideas then :lol:

[Guest]

Still don't really understand how the blue temp sensor can effect this but i have just tried running it disconnected and it made no difference?

 

Blue temp sensor tells the ECU when the car is warmed up, so it can change from the cold settings... Doesn't sound like your problem though. Yours could be a number of things. If it's actually a misfire, then it's more likely to be something electrical, although this would surely mean it would happen across the whole rev range? Could be worth checking for simple things, like air leaks, perished pipes..etc. first, then if it still happens, i'd get it on VAGCOM.

It does seem strange though that changing the plugs made it worse? Could be a lead breaking down, or as you suspect, the dreaded coil pack....

 

Good luck..

[bigbluec 0]

Cheers steve, have run vag com but no fault codes have shown up which i guess is good and bad news!

Don't think it can be the leads breaking down as they're fairly new think i'm going to have to bite the bullett and buy a new coilpack if that isn't the cause I'll take it back or keep it for the future!

As for split hoses any ideas on which ones to check?

 

Edit:

Just a thought but are Injectors a possibility?

[Dogzyboy 0]

Similar problems to me at the moment. I've now replaced the plugs, leads, coilpack & fuel pump relay. Next on the list is the ECU relay (advised it could be this just last night) but I've had to order one, which I'm picking up tomorrow.

 

I get a click from the relays in the fusebox area when I'm getting the hesitancy/misfire problem, are you getting the same? It might be worth trying the ECU relay before the coilpack as it's £11 Vs £130.

[bigbluec 0]

No click that i've noticed from any of the relays but will have a closer listen when i get to see my car again on friday and let you know.

Keep hoping for some magical words from Kevhaywire or Dr Matt who seemed to be fairly clued up on these things.....!

[craigowl 0]

If the coilpack is the original and the car is over about 9 years old the plastic parts will certainly be cracked.

 

Possibly there was no arcing visible/audible due to some quirk at the time you did the test.

When the test works, you can hear/see the sparks (in poor light - not bright daylight) and hear the engine faltering at the same time.

Good luck with your investigation anyway.

[bigbluec 0]

Cheers craig to be honest i'm hoping that it is the coilpack! i just want it back to it's normal purring self!

Did the coilpack in pitch black with plenty of mist but will try a new one anyway i think

[dr_mat 0]

What about the cam position sensor?

[bigbluec 0]

Cps was replaced about 6 months ago and I can't remember it causing an idle tickover when it had gone last time? also no fault code has shown up on Vag-Com???

[Guest]

As for split hoses any ideas on which ones to check?

 

Edit:

Just a thought but are Injectors a possibility?

 

Check all the airway hoses and pipes. Make sure all the jubilee clips are tight, and that there are no perished vacuum hoses..

Could be injectors, but i doubt it. It could be down to fuel starvation though, so might be worth changing the fuel filter, and check that the fuel pump is working ok...

[bigbluec 0]

Will check all the hoses when i get a chance, fuel filter is new but i guess pump is a possibility.

 

Cheers for all the advice guys and keep the ideas rolling in!

[bigbluec 0]

Fixed :D it was indeed the coilpack it had started breaking down internally but believe it or not no cracks on the casing hence it wasn't arcing.

Big thanks to the Phirm for lending me a good coilpack to try.

[dub envy 0]

I'm having the same problem but only below 2000rpm... have changed all the leads and the coilpack. Was ok for a day then the misfire came back.

[mattkh 0]

Hi bigbluec

 

Well done.

What is involved in taking the coilpack off ?

 

can you please put up a picture of the internal breaking down of the coilpack.

 

Cheers.

[bigbluec 0]

Hi Matt, No piccies i'm afraid as the unit is still solidly in one piece.

Removing the coilpack is pretty simple:

1. Undo all 6 ht leads (may be worth taking a quick phone pic so as to see where they go back on!)

2. Using a spline/hex remove the 2 bolts holding the plastic cover on.

3. Unplug the coilpack (single large idiot proof plug)

4. Remove the 4 x 5mm alan bolts holding it on.

 

Refitting is the reverse of removal! ;-)

 

Edit:

Sorry to hear that dubenvy have you checked fuelling side of things?

 

mattkh if your sig is correct (1.8 16v) you have an old coil at the back with a king lead going to a dizzy not a coilpack

[dub envy 0]

cant really go wrong with the ht leads. The runners make it pretty easy putting them all back in the same order.

 

Would a fuel prob come up on vag-com. Had it down at g-werks the other day and no faults came up (well apart from abs..)

[bigbluec 0]

Not sure how clever the Vag-Com system is to be honest but i'm sure there are a few on here that can help with that side of things, think Dr matt and phattvr6 are pretty clued up on that side of things.

[dr_mat 0]

Some fuel problems can come up on VAG-COM, but it's usually only severe ones - you'd know from your MPG well before VAG-COM threw an error, most likely.