ZDrifter Posted January 17, 2007 Share Posted January 17, 2007 Hey Guys, I just got a boost controller on the Z and finally a boost gauge. So I have it set at 12psi but on the stock ECU its hittin the fuel cut because of the cold weather, seems like its better when its warmer out. Anyone have any suggestions, would playing with my fuel regulator help out at all or do I need to have my ecu re-mapped or go for tuning devices? ~Thanks Quote Link to comment Share on other sites More sharing options...
poop24 Posted January 17, 2007 Share Posted January 17, 2007 Set it at 11 psi...... or AEM EMS part # 30-1621 Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted January 17, 2007 Share Posted January 17, 2007 I would be setting it to a SAFE level until you can do something safer than mess with a FPR. Do it properly or you'll blow it up. Dave Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted January 18, 2007 Share Posted January 18, 2007 you should be fine with 12 lbs. What is your FP set at? It's still unclear of what your problem is..? are you driving your car hard cold? you dont need any fancy electonics to run 12 lbs. Quote Link to comment Share on other sites More sharing options...
Z U L8R Posted January 18, 2007 Share Posted January 18, 2007 another possibility if you didn't do it before you turned the boost up, is you might need to run a little bit smaller spark plug gap. it may be just blowing spark. i didn't have a problem running 14psi with a .028 gap. ngk 3330's bcpr7es come pregapped at .030 fyi (i have no idea what plugs u have in there other than seeing "rb280z") Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted January 19, 2007 Author Share Posted January 19, 2007 Stock RB25 with front mount inter. Stock Ecu, SARD fuel pressure regulator and ill have to check fuel pressure again last time it was set it was set by another shop and whatever stock fuel pressure is at, walbro 255, turbo back 3 inch, manual boost controller set at 11psi, plug gap is at .030. And it doesnt matter warm or cold it hits fuel cut. I tried goin down to 10psi and it still hits fuel cut. Any Ideas?? Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted January 19, 2007 Share Posted January 19, 2007 are you sure its fuel cut or just misfiring? clogged fuel filter, blockage in fuel line? unless your hitting rev limiter or reaching the speed governer, the ecu shouldnt be cuting fuel. Quote Link to comment Share on other sites More sharing options...
stony Posted January 19, 2007 Share Posted January 19, 2007 Ok you said you have a booste gage on it but are you sure its accurate? If your running the stock computer unmodifed it has a boost max (dont remember what it is) that when it reaches it it cuts fuel. you can put a fuel cut defencer on it but that is just tricking the motor that it is not seeing the booste that it is actually seeing. This is why i tell anyone that does the swap, in the states, not to mess with the stock computer. go standalone or find someone that is competent in tuning a rb computer ( good luck in the states) . you cant just turn up the booste and add fuel. it needs to be tuned. Main thing to remember is these JDM engines are fine with turning up the booste in japan cause they have 98+ octane right out of the pump. you put 90 or 93 oct in the car and try to run the same as they do in japan with the stock ingnition map you will eventually blow your engine. You are allready pushing the maps just by running stock booste with the gas we have in the pumps here in the states. So my sugestions to you is get a stand alone or some kind of piggy back that turns off the fuels cuts and allows you to modify the fuel and ignition curves. then have it tuned by someone that knows what they are doing on a dyno. It may be a little expensive initially but it will save you the cost of an engine down the road and it will perform better to. Allot of people say they can just tune it on the road with a wideband... this is true in some cases but on a dyno it is more controlled and i guarentee you will use less gas on a dyno then tuning on the road. Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted January 19, 2007 Author Share Posted January 19, 2007 Thanks for the suggestions. I know that I didnt want to mess with the stock ECU and everything is set from the factory for a reason. It'd just be best to keep it at 7psi until I get a tunable ECU. I want to try adapting megasquirt with the RB since I havent seen it done yet. I think I should just move to Japan also, they have everything better there:grin: Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted January 19, 2007 Share Posted January 19, 2007 I ran a boost controller with a stock ECU, so I dont agree that you can't run more boost. I ran 14. There is no fuel cut to speak of on my car, it would run so rich I would have misfire on the top end though. However, its freaking pointless, my car ran SO rich under boost that it was not making jack for power. I swapped to an apexi power FC, and on its base maps it ran much better. Idle was 100% tamer as well. You have to run some sort of management, stony is so right. You leave so much power/driveability/economy on the table with stock EFI. Evan 1 Quote Link to comment Share on other sites More sharing options...
Z U L8R Posted January 20, 2007 Share Posted January 20, 2007 all great, safe advice thus far, my question is do you have the oe boost sensor on your motor cause i always take that off. and if it is not on the motor, how's the ECU going to determine ANY boost, let alone too much, and or cut fuel. i don't think your problem is the ecu cutting fuel. i think you have a pretty simple problem, either with the fpr you're using, like it's not set right and/or just bad = easy test, try the stock fpr. or your problems not fuel it's ignition. possibly you're having coil pack issues, etc etc, the other thing is if you turn the boost up are you running 6's or 7 heat range plugs? i think with a little more information and testing on your part we can get to the bottom of your issue. Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted January 20, 2007 Author Share Posted January 20, 2007 I think I may have found part of the problem. I have been having hard starts lately in the morning and I think my fuel filter is bad. Also I am using the stock L28 Style fuel filter so could there be a problem with fuel delivery because of that??? Im thinking I will get a 300zxtt fuel filter along with new lines from the filter (cuz i need em haha) and see if that helps out at all. And when i say hard starts, it starts up in the morning when its cold but put puts and dies, after about 3 times it will fire right up. Quote Link to comment Share on other sites More sharing options...
poop24 Posted January 21, 2007 Share Posted January 21, 2007 I also agree about the fuel filter.... try tipping the filter upsidedown when you remove it, and make sure a bunch of rust and dirt doesnt come out.. You could have a contaminated tank, from that car sitting over the years.. If that looks good I wouldnt look past the ignition system either.. Something has always been up with that... Late Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted January 22, 2007 Author Share Posted January 22, 2007 Checked my fuel pressure today and its at 50psi. A lil high im thinkin.. So should I bring it down to around 42? And change out my fuel filter and lines around it and see what happens? But I will just keep it around 10psi boost until I get a standalone. Anyone ever try GREDDY E Manage?? Quote Link to comment Share on other sites More sharing options...
Z U L8R Posted January 23, 2007 Share Posted January 23, 2007 your fuel pressure is a little high but all in all it's fine. put it at spec and let's move to ignition. what exactly is your boosting problem? is it smooth if you slowly boost to 12, but hesitate,sputter, or jerk when you mash it to 12. does it act up at 3-4k rpm? describe your test drive. what spark plugs are you running? what motor are you running? does your car warm up to operating temperature (aka does it have a thermostat)? have you ever replaced your coolant temp sensor? i'm willing to bet, unless your coil packs are starting to ark thus causing your ignition to break up at higher rpm, if you get some ngk bcpr7es (part #3330) and gap them to .028 it'll fix your problem. one other thing, how's your intercooler piping? is it sound. check all the clamps and make sure they're tight, make sure there's no dry rotting or cracks in the silicon, to make sure the more boost did not create a boost leak. 12psi is not a lot at all Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted January 23, 2007 Author Share Posted January 23, 2007 Starts hesitating around higher rpm's like its losing fuel but it doesnt backfire or anything like its running rich. In first gear it will do it almost immidiatley after reaching 9lbs of boost. 2nd gear gets a lil better but all gears wont reach up into the rev's like they should. I need to get it back down to 7psi and see if it still does it. I have a rb25det and it does have a thermostat and it warms up to operating temp. Im running NGK'S not sure of part number but they are gapped at .030. Quote Link to comment Share on other sites More sharing options...
Z U L8R Posted January 24, 2007 Share Posted January 24, 2007 try the 3330's bcpr7es gapped at .028 ~$10, if that doesn't fix it you're probably going to need coil packs, i would then convert it to the wasted spark system with spark plug wires =] it's cheaper and looks sexy too Quote Link to comment Share on other sites More sharing options...
zcar? Posted January 29, 2007 Share Posted January 29, 2007 why dont you just drive that pile off a cliff haha buddy Quote Link to comment Share on other sites More sharing options...
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