Guest ON3GO Posted March 9, 2006 Share Posted March 9, 2006 okay i dunno what the deal is. Car is running a pretty much stock L28ET motor, mild ported head... talking very mild. mild ported N42 intake manifold, T3 turbo, stock internals, 2mm headgasket so my compression is a tad lower the stock. its being ran on MSnS-extra. other day ago we were street tuning my Z, at 7psi it was fine, weather was pretty crisp and around 70 to mid 60 degrees.. was around 12.5 at WOT to about 11.9 right at redline. tried to tune for 12psi... run into a miss up to and pop and breaks up, pops flames and all that crap. never got to look at the AFR's when it happened so i dunno if its going rich or lean but my guess would be lean... now.. i thought hey maybe my spark gap is to high at .032.. dropped it to .027 or so and still same problem... it has a BRAND NEW and known to be good: Blaster 2 coil, NKG wires, Good Dizzy, new plugs, MSD box.. i cant figure it out.. if i pop boost up a tad to 8psi it does it, 9psi it does it, 10psi and up.. it seems like the higher the boost the eariler the miss comes on, but it could be that the car is just reving up way faster with the added boost. now.. last night it was doing it at 7psi, with the GReddy profec B turned off... so with that said im thinking its in the Tune...... Thumper is saying its not.. what you guys think? what you think i should double check? any ideas??? mike Quote Link to comment Share on other sites More sharing options...
dapiper Posted March 9, 2006 Share Posted March 9, 2006 Bad plug. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 9, 2006 Share Posted March 9, 2006 like i said all new, all gapped correctly.. did it with the old set of plugs, does it with the new set.. mike Quote Link to comment Share on other sites More sharing options...
BirdmanZ Posted March 9, 2006 Share Posted March 9, 2006 Did you check the fuel pressure? Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 9, 2006 Share Posted March 9, 2006 its perfect.. i can view my fuel pressure as its on my cowl. its dead on.. mike Quote Link to comment Share on other sites More sharing options...
oinojo Posted March 9, 2006 Share Posted March 9, 2006 i experienced the same problems your saying but with my turbo honda. What it was, was my injectors im upgraded to had a spray pattern that did not cooperate well with my engine. Perhaps you might have the same deal? just throwing out ideas... Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted March 9, 2006 Share Posted March 9, 2006 were all using the same 440cc injectors... and we've cleaned and flowed his before install. Quote Link to comment Share on other sites More sharing options...
Thumper Posted March 9, 2006 Share Posted March 9, 2006 Hey mike just had an idea. It might be the fuel injectors. Remember when we had two stuck injectors and then we loosened the hold downs and they started to work. Well I would loosen all the hold downs and lightly tigheten them. Then hook up your wideband and make sure it isn't running lean. Damn umm just remember I never saw your a/f ratios go lean when you had this problem so that might not be the problem but its still worth a try only 5 minutes to do. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 10, 2006 Share Posted March 10, 2006 i was thinking that sorta too. remember my car has that bad vacuum leak at the injector that i sorta fixed with the zip tie.. well what if it at the higher boost levels and higher rpms the engine moves alot more causing that vacuum leak to happen...... what ya think? Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted March 10, 2006 Share Posted March 10, 2006 Flames from the front or back? If it's from the back I'm thinking too rich or weak spark. Front is definately lean or too advanced timing. Mario Quote Link to comment Share on other sites More sharing options...
Drax240z Posted March 10, 2006 Share Posted March 10, 2006 i was thinking that sorta too.remember my car has that bad vacuum leak at the injector that i sorta fixed with the zip tie.. well what if it at the higher boost levels and higher rpms the engine moves alot more causing that vacuum leak to happen...... what ya think? I don't think you can actually "fix" anything with a zip tie... can you? Sounds like a possibility though. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted March 10, 2006 Share Posted March 10, 2006 Have you played with dwell settings on the megasquirt? My mate had a similar issue with his RB30ET (GT35R) and that was his problem. Dave Quote Link to comment Share on other sites More sharing options...
Sparks280zt Posted March 10, 2006 Share Posted March 10, 2006 Mike I sent you a PM to see if you ever got those injectors? I take it from this post you did? Im sry it took so long, USPS can be slow. If any of the injecors are bad PM me and I will make it right. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 10, 2006 Share Posted March 10, 2006 injectors are working great so far.. thanks dude! mike Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted March 11, 2006 Share Posted March 11, 2006 still have the miss.. the fuel injector vacuum leak wasnt it... mike Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted March 11, 2006 Share Posted March 11, 2006 Dwell? Dave Quote Link to comment Share on other sites More sharing options...
Guest norm[T12SDSUD] Posted March 11, 2006 Share Posted March 11, 2006 My car is not a Turbo, but every time I have had a high rpm miss it has been ignition timing related. Each time I have advanced the timing a bit and my miss has always been cured. Try it and see if it helps. Later,Norm Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 11, 2006 Share Posted March 11, 2006 Mike you need to fix the vacumn leak first, that completly fucks up Megasquirt. -Ed Quote Link to comment Share on other sites More sharing options...
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