chris1986 1 Posted September 24, 2006 1.6 8v gti, for some reason it's miss firing on no 1 + 2 cyl there is spark and therer is fuel and the car runs fine on the other 2 cyls. i have even had the head off to see if there was anything wrong but nothing and there was good enough compression. so now i'm thinking it must be a sensor somewhere. i've heard about the afm, but could this just make 2 cyls miss? also if any one has one lying round that wants to see let me know. anyone ever seen this problem before? cheers....chris Share this post Link to post Share on other sites
philfingers 5 Posted September 24, 2006 It's one of two things. It's either ignition or fuel injection. The injectors aren't sequential so try swapping the plugs around. Have you chnaged the plugs? If it's firing on the other two cyls then it can only really be dizzy cap, leads or plugs to those two cyls or the injectors themselves. Unless there's a mechanical problem, ie borken valve springs, bents valves etc Share this post Link to post Share on other sites
chris1986 1 Posted September 25, 2006 hi, i have swapped injectors round and tried plug leads, has new plugs in it. and i've had the head off to check and its got good compression. so i thought it might be a sensor of some kind. if the afm has gone will it cause more than one cyl to miss? Share this post Link to post Share on other sites
205007 12 Posted September 25, 2006 what about the injector wring have you had a meter on it? Share this post Link to post Share on other sites
philfingers 5 Posted September 25, 2006 It won't be the AFM, if that's gone it won't run. It's something specific to the cylinders. As 205007 says have you checked the injector wiring? Easy way to do this (sorry I should have been more clear) is swap the injector plugs around not 1 to 2 but 1 & 2 to 3 & 4. As mentioned the injection is old school, it's not sequential so it doesn't matter whihc injector plug goes on which injector. It's possibly you have a duff 'new' plug, although unlikely. If you have the old plugs pull all the plugs leads off and fit the old plugs so they're floating about on top of the cam cover (disclaimer here; disconnect the injector plugs!). When you turn it over you should see all the plugs firing up all after the other. You have a spark, you have compression, have faith, it's nothing serious! Are you sure it's 1 & 2 it's missing on (pugs no 1 is gearbox end!). Use the spit test, spit on your finger and touch the exhaust manifold after it's run for 30 secs or so, where the manifold leaves the head. You'll soon know which it's firing on. Obviously don't burn yourself! Let us know how you get on Share this post Link to post Share on other sites
chunkymonkey 0 Posted September 25, 2006 you should be an expert phil in this missfire topic as im sure youve had many a sleepless night trying to fix your old one before chucking in the towel!! i do hope your 309 build puts a smile on your face it sounds like its going to be a cracker cheers gaz Share this post Link to post Share on other sites
chunkymonkey 0 Posted September 26, 2006 you should be an expert phil in this missfire topic as im sure youve had many a sleepless night trying to fix your old one before chucking in the towel!!i do hope your 309 build puts a smile on your face it sounds like its going to be a cracker cheers gaz although phil when you get past the point of fitting the engine dont be a cheap skate by tapping out the bleed nipples on your rear calipers as it,ll only cost you more in the long run.you know like when you come round to bleed them again.but i guess you werent bothered about that on the last car you had as you were selling it anyway cheers gaz Share this post Link to post Share on other sites
chris1986 1 Posted September 26, 2006 thanks for replies. was working late tonight so will try the spit method tomorrow Share this post Link to post Share on other sites