HEEEELLLLLPPPPP!!! Got a bad misfire :o(

[st4stokie 10]

Really need some help and advice on this I've tried everything I can think of. Drove the car back from Southend and it was quite lumpy all the way back. Its had new coil pack, new bosch plugs and leads. It's got a brand new bosch battery too I've checked the oil and water and there is no trace of oil in water or vice versa. I've put injector cleaner in with the fuel when I topped up. The problem is mostly on tick over it seems to be missing and when driving if I put my foot down it seems to go asthough its got a cylinder down then picks up and runs smooth. I gave the plugs a good clean yesterday (although they were pretty clean anyway) and its made no difference. I wondering if the coil pack is faulty or if there is a problem with the injectors. I've ordered a ecu to engine and ijector to ecu loom (the one with the big round plug) from a member on here as the previous owner thought that the one on the car was abit dodgey. I'm running out of ideas as to what could be causing it. Has anyone had this problem or a similar one so they could advise me where to look next, or does anyone have a clue what the cause could be? :scratch: All help greatly appreciated Thanks in advance Neil

[dumptyboy 0]

I had a similar issue, although my misfire/hesitation was more noticeable when I was idling and then hit the throttle. I changed the fuel filter, fuel pressure regulator and the blue coolant temp sensor and the car now runs like a dream! Have you changed any of these items?

[st4stokie 10]

Thanks dumptyboy I'll take a look at changing all of them as mine is the same as yours as well. I've also noticed that someone has bridged the brown/red wire on the big round multiplug on the engine and done a really bad job of it (stripped insulation and twisted the bridging wire onto it with no insulation) so I'm wondering if that could be the cause too

[VW_OwneR_85 1]

try cleaning the MAF sensor or using someone else's that you know works 100%

[CazzaVR 0]

Have a good look at the coilpack. You'll have to remove it for inspection as sometimes the cracks are tiny and underneath. Only takes 15 mins to remove. You can cover the cracks in epoxy resin (araldite etc) if you don't want to buy a new one. vwspares.co.uk seem to be best on price.

 

Also worth checking all the above + vac leaks. Recently found a hole underneath my intake pipe, which was causing lumpy running and poor starting. Would never have found it without removing the pipe.

[st4stokie 10]

I'm off work monday and tuesday so i'll have a good look at it. Will the 4bar regulator from a 1.8t fit the VR6?

[st4stokie 10]

Ok so I fitted a 4 bar fuel reg this morning and it ran like a dream took it for a run but after about 10 miles the problem came back :bonk: Could this be because the 4 bar is too much pressure or should I now be looking elsewhere?

[st4stokie 10]

Just got back from having the C plugged in to a code reader came up with 00513 engine speed sensor G28 no signal when not running but also when is was running. Looks like this could be the issue so I'll be fitting one on thursday when I finish my nights and hopefully it will be sorted :dance:

[emmib 10]

hi i had the same problem and like you i had the coil pack changed and she was still unhappy, so i then had the cam sensor replaced and she now runs like a dream, give it a try :smug:

[Hofmiester 10]

I thought the C was 4 bar fuel reg as standard?

[jonnykillpop 10]

I thought the C was 4 bar fuel reg as standard?

 

Yeah it is or my VR6 always had 4 bar since bought it, and yes the 1.8t fits as got one in garage and fitted when had similar prob., mine turned out to be the crank sensor (also take rubber bung of plug and check wiring at end most of them are frayed or nearly worn through) but hesitation was mainly a brand new Lambda sensor from Europarts which turned out to be dodgy, ran better disconnected. They did change it no bother and now runs perfect. Also had new coilpack, 10mm Bremi leads, cam sensor, and TPS,temp sensor and MAF turns out nothing much wrong wi the old ones but never hurts to have spares of all these, and now running incredibly well, but the crank sensor and lambda were deffo the culprits.

Check your MPG, with bad crank sensor was showing 16 to 19 tops, soon as changed 25 min even when screwing it, over 30 on a motorway taking it easy.

 

If ya local, South Shields, Tyne and Wear, or if anyone local having similar probs ya welcome to come round and fit any of these bits to eliminate, as pretty much full set of spares now.

I refitted the Corrado Fuel pressure thing as though nearly identical the Corrado's has much bigger diameter hole at end, and mine looked just about new (mine had new engine shortly before bought it so probs is) had the 1.8t one fitted when had dodgy lambda in and made neither better or worse.

[jonnykillpop 10]

P.S. If your Pressure Regulator is dodgy I'm told 5 bar ones which you can get for VR6 are better anyway and VW only fitted 4 bar one for emission regs. and slightly better mpg figures, but for everyday running does'nt really effect, though hav'nt tried one myself.

[st4stokie 10]

I'm in stoke-on-trent or i would of taken you up on the offer to try the bits you have. Never noticed the diameter of the hole on the fuel reg I've still got the original so I'll put that back in as that defo aint the problem. Ive had new crank sensor fitted and its made no difference. So today I've taken the plugs out again and checked them all were good except for No'1 which was abit black and slightly wet so I cleaned it and refitted it but still ran the same. Then I thought I'd remove the lead from that plug and it remained the same so now I'm suspecting the No'1 plug lead is knackered.

[st4stokie 10]

UPDATE!!! A kind member on here lent me a coil pack and the problem was solved. So picked up a second hand Bosch one on ebay less than 12 months old and guaranteed working. This was sent via hermes who left it outside the front of my house for it to be stolen :shocked!: I've also had the large round loom plug replaced as the contacts in the old one were badly corroded this has also made a difference but now when the engine is warm the car struggles to start. The only thing I can say is different is that when the wires were reconnected there were 2 blue wires that we were unsure about Does anyone know what these are to? I think one goes to the blue coolant sensor but not got a clue where the other goes to.

[dumptyboy 0]

The blue coolant temp sensor should have 2 wires going to it, do you only have one?

Rob.

[st4stokie 10]

There are two wires Yes only one is Blue

[st4stokie 10]

This is all sorted now runs like a dream LOVING IT!!!!:dance:

[Dox 23]

And the fix was?

[st4stokie 10]

Coil pack. Plus switched the two Blue wires over on the large round plug from the ecu.