Ok, so the problem is I have misfire when I hit around 1bar of boost. I have just fitted new coilpacks and BKR7E plugs, didn't check spacing yet as I can't find my feeler gauge So I'm stuck now as to what it could be. Bear in mind it runs fine at a lower boost setting (0.2/0.3bar) and idles fine too. I have gone over the bay and double-checked for any split hoses, etc. All good there. Boost gauge is reading correct on idle (i think lol) like -0.7 bar and is boosting too around 1.2 bard. So I'm just guessing here, but I don't think there is a boost leak and that a leak is the causing the misfire. I do remember now it started to appear when I used octane booster with 99 octane fuel. Now I'm thinking could it be the O2 sensor? But surely that would cause more running issues, regardless of what it is boosting at? So it runs fine with the boost turned down and with the boost up its fine just doesn't like when its under load. Other things I should try I guess would be DV and N75? Any idea's before I go and replace the DV, N75 and 02 sensor?
spark plugs, get some bosch super 4s in there, 12 on trade from halfords. Mine was oing the same as yours, I had fancy iridum denso plugs in there... it would miss on boost and run like a dog, but at all other times it was perfect! I went though the full works, new boost hoses, stripped the throttle to make sure I got it full open, new N75 valve and tried a spare one! nothing happened.. new plugs and all is fine! so fine Ben upped the boost for us when I went to see him about the missfiring and another issue (I chnaged the plugs before I set off to see him that morning) Ben said they has been told of plugs causing many issues on only reccomend fitting the bosch plugs now.
Mmmm, ideal bud! I'm doing another mk3 20vt with my mate, so borrowed the n75 valve, didn't change anything. Unplugged the O2 sensor and tried running it but no luck. Ben suggested the fuel pump, I reckon it is a spark problem and I'm defo going to try what you said! Thanks mate! Which bosch super 4 plug do I get? Was your misfire aggressive? Mines hits full boost and misfires very agressively, almost like a ooilpack has blown.
I want to check the gapping, typical that I have lost my f**king feeler gauge! Its the only tool I have lost, like ever! I got one in the post
Gapped two sets of plugs and still hasn't solved it. How do I go about checking/fixing the dwell? If you could explain dwell in a sentence that would be great too
I'm going to borrow a crank sensor from my mates 1.8t and see if it fixes the problem. Don't know what else it could be...
aaahhhhh!!!!!!! it would be worth popping the pump oout of the tank and checking the part numbers, as it SHOULD be a 3 bar pump... but there is also a 1.2bar pump which should only be used a a couple fo 1.8s... but no garatee which one you have. post up what numbers you can see on the pump and Ill check etka and see what it says
Aite, will do. I'm running a pump from a VR at the moment, it had done almost 8,000 miles before I started having issues. Thanks mate
ahh if its defo from a VR then if its a pre96 its a 4bar or post 96 is 3bar, but either way the pressure and flow rates are man enough.. but you can still check the part numbers if you want. I still think it would be worth poppoing in a set of bosch +4 plugs
erm im not sure, as I have been sent to germany today for work so my internets slooooow This is what I have in mine - bosch kit 509 http://www.halfords.com/webapp/wcs/..._productId_194849_langId_-1_categoryId_165736 find some one with a trade card as they are !2 on trade! or from VW I think thiers are 13 on trade for a set of 4 for the 20vt with 225bhp
