colerongo Posted October 30, 2006 Share Posted October 30, 2006 ok, i have a 240z with an l28et. i have been driving it for the past couple months stock. but i decided to start modifying it. i got an intercooler hooked up. as soon as i did it, the turbo started making a whoosh, whoosh, whoosh sound on downspool. it drove awesome though. i have ta boost controller hooked up, it is set at 8.5 psi. i also got a walbro 255 lph fuel pump hooked up. it's much quieter and seems to be working perfectly. i have an aeromotive boost referenced fpr, but don't have it hooked up yet cuz im waiting for fittings to arrive from summit. it's been driving perfectly for about a week with these mods until last night a connector for the w/r power wire from the alternator melted. i think it was because it was corroded. i crimped a new one on and i once again have elelctrical power. but, the engine isn't running the same. i don't know if its related. it's idling lower and rougher, and it studders until about 3000 rpm's. it basically feels like the engine is cold. after 3000 rpm it feels a little smoother and much faster. i took the spark plugs out and they were black. they didn't smell like gas though. what does this mean? is it running lean? what could cause this? could my injectors be clogged? the spark plugs are pretty new but will it fix the problem if i replace them? any help would be appreciated because i've spent hours searching for similar threads. thanks Quote Link to comment Share on other sites More sharing options...
madkaw Posted October 30, 2006 Share Posted October 30, 2006 Battery? Quote Link to comment Share on other sites More sharing options...
jtmny1999 Posted October 30, 2006 Share Posted October 30, 2006 It sounds like the alternator is not charging and the battery is about to die. Happend to me.......... make sure to check both the alternator and battery, also check for other bad wires. Jose Quote Link to comment Share on other sites More sharing options...
JSM Posted October 30, 2006 Share Posted October 30, 2006 Black plugs mean to much gas, which may go w/ your running rough. Throw some new plugs in see if it runs okay. Then try and figure out why it is running rich. Quote Link to comment Share on other sites More sharing options...
colerongo Posted October 30, 2006 Author Share Posted October 30, 2006 ok, i replaced the spark plugs and ran the car for a couple minutes. the plugs are pretty much drenched in fuel. too rich. now i need to figure out why. could it have something to do with the walbro 255lph pump i just installed? the problem seems to have started shortly after i installed it. maybe my stock fpr isn't functioning properly and it's allowing my pressure to get too high? my fittings should be arriving today at 2:00 so i will install my aeromotive fpr and set the pressure at 30psi. if anyone can think of anything else i should check that could be the problem let me know. Quote Link to comment Share on other sites More sharing options...
colerongo Posted October 31, 2006 Author Share Posted October 31, 2006 ok, i just installed my jsk fuel rail and my aeromotive fpr. after fixing a couple leaks, i got it to hold pressure. it's at 65 psi. way too much. after turning the bolt on top of the regulator to turn the pressure down, the gauge still read 65. i don't know why, but my regulator isn't allowing my to adjust it. at 65, the car ran exactly the same as it did with the stock regulator, like sh%#. i think if i can figure out what's wrong with the regulator, and get my pressure back down to 30psi, it will run perfectly. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted October 31, 2006 Share Posted October 31, 2006 Your return line might be too small or clogged/restricted. Mario Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 31, 2006 Share Posted October 31, 2006 Bingo, it'sa 240, the fuel return lines are too small for EFI. If you have 75+ Z you can pull the steel fuel lines and swap. Quote Link to comment Share on other sites More sharing options...
colerongo Posted October 31, 2006 Author Share Posted October 31, 2006 i bet you're right. i am running stock lines. i welded a sump with 3/8 npt fittings but haven't changed the lines. clifton mentioned a larger diameter vent line that i could use. i don't remember ever seeing it, but where is it? do all 240z's have one? if not i guess i'm gonna have to run new lines. might as well upgrade my fuel in line while im at it. Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 31, 2006 Share Posted October 31, 2006 What he's talking about is swapping the vent line that goes to the charcoal canister with the return, which should actually work. Quote Link to comment Share on other sites More sharing options...
spotfitz Posted October 31, 2006 Share Posted October 31, 2006 I don't think a '72 240Z has a charcoal canister from the factory. I know the '72 I was looking at just last Friday only had two fuel lines on the passenger side frame rail. Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 31, 2006 Share Posted October 31, 2006 Maybe it's just the Cali spec models that have it. Quote Link to comment Share on other sites More sharing options...
DCZ Posted October 31, 2006 Share Posted October 31, 2006 Vent line on the 240z should run down the driver's (left in US) side frame rail in the engine compartment. Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 1, 2006 Share Posted November 1, 2006 Really? That's odd. Learn something new everyday I guess. Quote Link to comment Share on other sites More sharing options...
colerongo Posted November 1, 2006 Author Share Posted November 1, 2006 you're right DCZ, the vent line runs along the driver side frame rail. i hooked that line up, and it started up and ran great. no more hi pressure. it's also a plus becaue with my fpr mounted on the driver's side, the boost reference line is shorter, so less lean issues while building boost. i read a post about that last night. thanks for all the help. Quote Link to comment Share on other sites More sharing options...
24OZ Posted March 5, 2007 Share Posted March 5, 2007 This is an old thread that i have just revived.. I am wondering if the fuel return line was the issue in the end. I have a 240Z that I am turbo charging and I wonder if using the stock fuel return will cause me any problems. Thanks Quote Link to comment Share on other sites More sharing options...
X64v Posted March 5, 2007 Share Posted March 5, 2007 Yes, it will. The vapor line mentioned will do just fine. I cut it in the back of the car by the tank, and ran the line directly into one of the tank vents. Quote Link to comment Share on other sites More sharing options...
badjuju Posted March 14, 2007 Share Posted March 14, 2007 "one of the tank vents"? Quote Link to comment Share on other sites More sharing options...
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