PurpleDinosaur Posted May 4, 2007 Share Posted May 4, 2007 So going against the reccomendations of the import haters at the local dragstrip I shot my little purple truck with the Z motor with a 75 shot of nitrous. 12:40 at 110mph and I blew a charge pipe at the 1000 foot mark and that was with a 2.4 60 foot time. So I fixed the pipe when I got home, and for the hell of it, I pulled the #1 plug from the cylinder head. GHOST WHITE!, Way lean. Didn't hear any knocking at all. Ran Beautifully,Except for the charge pipe.What can I do to fix this lean condition?. Here are the Specs. 1986 300zx turbo intercooled boost at 15psi, 110 Octane fuel, Timing set at 18 degrees btdc 1993 Nissan Hardbody Fuel pump, Stock NGK plugs (heat rating of six, gapped at .044) I just changed the plugs to NGK's again but I went with a 7 with a .044 gap. Now it runs like crap like its fouling the plugs with 2 much fuel, any suggestions? Quote Link to comment Share on other sites More sharing options...
tlmaniac Posted May 4, 2007 Share Posted May 4, 2007 well i would say you are running out of fuel at 15psi if you are using stock z31 turbo injectors. i have an 86 turbo myself and with stock turbo and fuel even intercooled is tough on them.i burned a piston like that so i am now building a vg30det to put in it. check out the turbofaq at z31performance.com lots of soch power specalists there. Quote Link to comment Share on other sites More sharing options...
nismopu Posted May 4, 2007 Share Posted May 4, 2007 stock 93 HB fuel pump and your truck is still alive? This just reenforces my belief in the old single cam VG and their toughness! The stock fuel pump is probly your biggest factor and you can run stock injectors on intercooled vg with 15psi of boost but thats the limit. Im sure the nitrous doesnt help either so I would look into a walbro 255lph fuel pump and some bigger injectors. peace. Quote Link to comment Share on other sites More sharing options...
Pete84 Posted May 5, 2007 Share Posted May 5, 2007 Stupid question, but how do you inject the extra fuel with nitrous? Is that a part of the nitrous system? Quote Link to comment Share on other sites More sharing options...
Thumper Posted May 5, 2007 Share Posted May 5, 2007 Please replace that fuel pump before motor goes boom. And get a WB. Quote Link to comment Share on other sites More sharing options...
PurpleDinosaur Posted May 5, 2007 Author Share Posted May 5, 2007 I can understand replaceing the fuel pump, I get that part, but the fuel problem only started when I added the NOS. I've been running this truck with 15psi of boost for over a year and a half with no problems, my plugs burn brown with the NGK6's anyway, and my air/fuel meter reads lean at idle and excellent when im gettin on it. So if I put a better fuel pump on it I should be able to get it to work with stock plugs, right? Quote Link to comment Share on other sites More sharing options...
Guest B.V.F.C.S240Z Posted May 5, 2007 Share Posted May 5, 2007 B.V.F.C.S240Z need to check injctor,make sure they did not melt them and run BCPR6ES-II plugs and add extra ingctor to add fuel with nos shoot. Quote Link to comment Share on other sites More sharing options...
PurpleDinosaur Posted May 5, 2007 Author Share Posted May 5, 2007 I have a wet NOS system, the shark nozzel holds and distributes the fuel and the nitrous. You have to run wet for a forced induction engine dont you? Quote Link to comment Share on other sites More sharing options...
PurpleDinosaur Posted May 5, 2007 Author Share Posted May 5, 2007 here is a pic... Quote Link to comment Share on other sites More sharing options...
nismopu Posted May 7, 2007 Share Posted May 7, 2007 i never really had fueling probs with the turbo HB I built either using the stock pump but it didnt help when we were trying to do pulls down the road and it was maxing out. peace. Quote Link to comment Share on other sites More sharing options...
1FASTKINGCAB Posted June 9, 2007 Share Posted June 9, 2007 When your Solonoids open you get a substaintal pressure drop in the fuel system. Don't "Replace" your pump, snag another D21 pump a run dual in tank pumps. you will Double you fuel systems flow capacity. Your stock fuel systems should be maxed out @ 15psi no juice, and when you add that pressure drop to the system your injectors arent pumping out thier rated CC's per min and your nozzle insn't dumping enough fuel for your shot. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted June 9, 2007 Share Posted June 9, 2007 The fuel pump may be limiting, as it may not deliver enough fuel pressure and volume at 15 psi. Boost alone at 15 psi, it may be fine, but when you are tapping the additional volume off, it may not be keeping up... Nice runs BTW Quote Link to comment Share on other sites More sharing options...
Slow_Old_Car Posted June 9, 2007 Share Posted June 9, 2007 pipes will stay on better if you run some better clamps/connectors. looks like your rubbing rubber connectors w/ worm gear clamps. get some 2-3 ply silicon connectors and t-bolts, you'll never blow a pipe again. as for your nitrous issue, cheap insurance if you have the engine bay space is put a secondary fuel system for the nitrous in there w/ some 105oct, run a 1 gallon cell, fpr, the noid, and a pump... a bit much for a small wet system i realize, but your playing with boost plus a air catalyst. A little octane padding under spray wouldn't hurt. Quote Link to comment Share on other sites More sharing options...
maxtor Posted June 15, 2007 Share Posted June 15, 2007 I run a second electric fuel pump for the nitrous. Your stock fuel pump is not able to give you enough fuel for both. You are lucky you did not burn a hole in your pistons. Also you need to retard timing when adding nitrous. I think the standard is 2 degrees per 50 hp of nitrous. Quote Link to comment Share on other sites More sharing options...
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