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Model specific boards => Golf mk2 => Topic started by: ianmaxtec on 05 July 2012, 19:17
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The compression in my engine is too high (as a result of skimming and a re-boar). I have tried everything to prevent pinking, but no joy. The maximum pressure should be 180psi, and I am getting 195psi. I am considering a de-compression plate, and was wondering has anybody tried one of these?
(Cannot offset the timing any more or the car wont run, checked the advance weights in the distro, they are fine, tried all sorts of octane additives, none work with the exception of Millers oil, which lifts the octane rating by 2 points, and does help reducing pinking, not interested in 2 head gaskets, as there is no guarantee they will seal)
Any suggestions would be welcome..
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what about using shell v max? fuel
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I have tried all available fuels (In Ireland), and none really make much difference unless you add the octane "booster"
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barking up the wrong tree.
you have good compression but it's not excessivly high i've run higher without issues, check your fueling to me it shounds like the motors not quite getting enough fuel or possobly it has the wrong grade of spark plugs in
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As far as I know there are no fuel problems, and the spark plugs are correct. Just to recap: if i run the car without a "octane booster" it pinks so much I am afraid to drive it (for fear of damage). I have tried different fuels, adjusted the timing to the point the car will not run..........the only way I can avoid pinking is to add "octane booster". The car used to pink now and again, and when I rebuilt the engine (head skim and re-boar) the pinking got much worse. There is loads of power, which I thought would rule out the possibility of fuel issues, the spark plugs are a brownish colour, and are the correct type. I also checked the advance weights in the distro (dizzy) and they are fine, as are the springs. What kind of PSI were you running your car on Danny?
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What engine? I used a vernier pulley on mine when the head was skimmed to the max. Sorted my annoying timing issue.
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8 valve k-jet engine, engine code EV...........PLEASE EXPLAIN MORE MR BLUE
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I would try going cooler on your spark plugs by a couple of grades. You might have the right plugs for your engine - but that is probably at normal compression. With the increased compression they could be running too hot.
Just been surfing on it - and retarding the timing helps to reduce it. If you have been advancing it, try going the other way.
The vernier pulley will help dial in cam (valve) timing - do you suspect yours might be out? It won't help with ignition timing.
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I believe because the distance between the crank and cam will have been shortened by a heavy skim the valve timing will be out
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Should have added but less than a tooth hence the possibleneed for a vernier. I could be wrong though.
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K jet system is old and mecanical and sensitive to knocks, it's not uncommon for it play up after you've done magor surgory on the car.
i think you would find it very worth while to do some basic checks,
system and controll pressure. then injector flow - remove the injectors and place them into glass bottels whilest still connected to there fuel lines, then put a switch across the fuel pump relay so you can remotely turn the fuel pump on and off whilst looking t the injectors.
wedge the metering head flap open and run the pump, observe amount of fuel in each bottel after seat time ( eg 30 seconds ) also take note of the spray pattern.
on an old k jet motor it's not uncommon to find injecrs spraying uneven amounts of fuel and one or maore injectors with a bad pattern as wel as system and controll pressures been out. the whole lot dose need a good going over every now and again, known a lot of 16vs regain 20-25 bhp after the fuel system has had a good going over
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injectors are new (well they were when I rebuilt the engine, app 20K miles ago). I am tempted to try a different plug (as suggested), will order some in and see how it goes. Im pretty sure the injectors are fine, dont know about the injection system, there does not appear to be much to adjust. where would I start with the metering head (assuming the injectors are OK)
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you have to remove the injectors to measure flow.
there is an allen key beside each injector outlet to trim the fueling, ( minor tweeks on these like 1/8th of a turn at a time )
first off i would look at the warm up regulator and chack the system and control pressures and that the wur is actualy functioning, then match the injector flows and finaly set the CO up then it should go much better and not pink