Stoffregen Motorsports Posted March 28, 2017 Report Share Posted March 28, 2017 A stock fuel pump (Nissan brand) usually supplies 4 psi. Don't know about aftermarket pumps, but it sounds like your has too much. It's important to distinguish between cheap and good quality fuel regulators. A cheap regulator (like the ebay kind with the large dial on it) will restrict fuel flow. A good regulator, like the Holley unit, does not restrict flow. If you get a Holley regulator, you will also need a gauge. Once you get the pressure set, you can remove the gauge if you don;t want to look at it. And make sure you get the "low pressure" Holley regulator (1-4 psi). Or you could spend the money elsewhere and get an OEM Nissan fuel pump. 2 Quote Link to comment
russaroll Posted March 30, 2017 Report Share Posted March 30, 2017 I'm running a single 45 on a lynx mani. Niki mechanical fuel pump and I think the timing is set at 10 or 12. No complaints 1 Quote Link to comment
willz Posted March 30, 2017 Report Share Posted March 30, 2017 Running some cheap mechanical fuel pump, not sure what happened to my stock one. I replaced it at some point trying to get an issue resolved. As far as timing.... I'm not there yet. My cousin in law is going to let me borrow his light, my crapsman took a crap. Wideband is going in tomorrow which should help with tuning after I find out where I set down my solder.... I'll make sure to contribute to this thread once I get everything lined out. Should be within the next few days 1 Quote Link to comment
Crashtd420 Posted March 30, 2017 Author Report Share Posted March 30, 2017 Got this on order.... might shed some light on tuning.... If any one need me to look something up once i get it let me know. I'll be giving it a good read and will post things as they seem relevant... Quote Link to comment
Stoffregen Motorsports Posted March 30, 2017 Report Share Posted March 30, 2017 They seem to imply that your engine will breathe fire after installing a Weber. 3 Quote Link to comment
Crashtd420 Posted March 30, 2017 Author Report Share Posted March 30, 2017 It would almost be a cool effect with people that run an open velocity stack.... Don't know if it could be done with a couple leds or something... but then again unless you were at a night time car show no one would ever see it... Quote Link to comment
willz Posted March 30, 2017 Report Share Posted March 30, 2017 That's exactly what I want... Balls of fire shooting out my carb 1 Quote Link to comment
willz Posted March 31, 2017 Report Share Posted March 31, 2017 Start up with the wideband. Got some gremlins to look for before I can ultimately say the readings are true, but so far.... I like Quote Link to comment
Crashtd420 Posted April 11, 2017 Author Report Share Posted April 11, 2017 So i know I posted this else where but I will add it here... I am running a p4070 carter fuel pump... it was putting out 6+psi.. and recently I couldn't start my truck... flooded with gas... well after I installed a regulator and set it to about 3 psi the motor fired right up, the weber was much happier.... 24 hrs later started no problem... so having the correct psi seems to matter, at least I believe it does.. i feel it was causing a rich start and running condition... so know my question is how much was that effecting my air/fuel ratio?. I knew i needed to rejet but now i feel base line from the dyno is wrong from the extra fuel preasure... i I guess the wideband o2 setup will be coming sooner than later... Quote Link to comment
Golde-boy Posted April 26, 2017 Report Share Posted April 26, 2017 Crashtd420- i want to know where u bought the fuel pressure regulator. i recently bought one but will not lower the psi bellow 9. This might be the cause of my car running rich all the time. Im running an l16 stock. i dont know what head it has. the carburetor is weber 48 on cannon manifold. trying to get my car to run right. I put a wideband 02 sensor yesterday and found out it is running really rich idle. i dont know how to adjust the carb to idle. just putting out there what my problems are Quote Link to comment
Stoffregen Motorsports Posted April 26, 2017 Report Share Posted April 26, 2017 Summit Racing. Holley 1-4 psi regulator. https://www.summitracing.com/parts/hly-12-804 1 Quote Link to comment
Crashtd420 Posted April 26, 2017 Author Report Share Posted April 26, 2017 Yup that's the one.... I even bought mine through autozone.... only took a day... What type of fuel pump are you running? Quote Link to comment
Golde-boy Posted April 26, 2017 Report Share Posted April 26, 2017 im using an inline electric fuel pump that pushes 13 psi. Seeing what u use i think ima need to change it to lower psi fuel pump Quote Link to comment
Crashtd420 Posted April 27, 2017 Author Report Share Posted April 27, 2017 I think the bigger key is keeping the volume up... that's why I liked the carter p4070 Because of the the high volume and low psi.. even at 3psi through the regulator It had real good volume... Quote Link to comment
willz Posted May 16, 2017 Report Share Posted May 16, 2017 I'm running the stock fuel pump. Having issues with it stumbling on its face on anything more than 1/4-1/2 throttle. Not sure it's a fuel delivery issue or a tuning issue Quote Link to comment
willz Posted May 16, 2017 Report Share Posted May 16, 2017 But I did just buy two ka24e engines for $150... so I might be running something different next year anyway Quote Link to comment
russaroll Posted May 16, 2017 Report Share Posted May 16, 2017 But I did just buy two ka24e engines for $150... so I might be running something different next year anyway what? how could this be? were they exploded? where were the ka when i wanted one? i had to buy a stupid sr. pssshhhhttt Quote Link to comment
Crashtd420 Posted May 16, 2017 Author Report Share Posted May 16, 2017 That's called right place right time and money in hand... nice score.... if there both good I'd get one running to so the swap and make the 2nd one nasty.... And for now is your o2 setup telling you any thing good? Quote Link to comment
willz Posted May 17, 2017 Report Share Posted May 17, 2017 One motor has a stuck valve, the other has a spun bearing. So make one good motor, build the other for fun (maybe turbo) Even came with a felpro complete engine gasket kit, ecu and wiring I'm going to do some tuning tomorrow, try and figure out what's going on. It's running stoic all the way up to 1/2 throttle, then leans out and starts running like crap. I wonder if I'm running too much or too little advance Quote Link to comment
willz Posted May 17, 2017 Report Share Posted May 17, 2017 what? how could this be? were they exploded? where were the ka when i wanted one? i had to buy a stupid sr. pssshhhhttt I've been looking non stop for weeks, can't believe no one bought them before me. They were on Craigslist for almost a full day, some dude tried low balling him at $130, which he was going to take if it didn't sell by this weekend.... as if Quote Link to comment
Crashtd420 Posted May 17, 2017 Author Report Share Posted May 17, 2017 Not sure timing will help with the air fuel.... I asked that during my dyno run... I was rich and I asked about adjusting the timing more? the guy at the dyno said it wouldn't matter to much till I adjusted my jets.... Might be time for you to look inside the carb and see what you have for jets, and even what size venturis.. my initial thought is to decrease the size of the air corrector.. Is it more throttle position related? What about your rpm range your running while testing? On the dyno I went wide open at 2500 up to 5000 for a baseline.... Quote Link to comment
distributorguy Posted May 17, 2017 Report Share Posted May 17, 2017 Aeromotive makes a low pressure regulator that actually works well, unlike the Holley setups that surge like crazy, but you pay for it. The good thing is this regulator flows enough fuel to supply a Weber, where the Holley may have issues. Timing helps lean out fuel mixture, but only to a certain extent. Jetting needs to be done as well. I didn't see a post of your AFR and RPM from the dyno... 1 Quote Link to comment
Crashtd420 Posted May 17, 2017 Author Report Share Posted May 17, 2017 Willz didn't go, and my dyno run is almost irrelevant ( I thought I put it in this thread)... either way I had to much fuel pressure. Afr ratio was ok at idle But basically at 2000rpm afr was up to 14, spiked lean when I went full throttle then afr dropped to about 9 or 10, then back up to 12 around 3500rpm till 5000rpm... And so far I've noticed no surging with the Holley regulator, seemed pretty steady, dropped about 1 psi from idle to full throttle but stayed stable .... How much does the pump matter? Maybe the type of pump and volume may make a differece to how the regulator performs not sure... Quote Link to comment
KoHeartsGPA Posted May 18, 2017 Report Share Posted May 18, 2017 I'm running the stock fuel pump. Having issues with it stumbling on its face on anything more than 1/4-1/2 throttle. Not sure it's a fuel delivery issue or a tuning issue Make sure your accelerator pump is squirting properly, there should be an adjustment to it, I know Mikuni does have it. Quote Link to comment
willz Posted May 18, 2017 Report Share Posted May 18, 2017 I actually backed the timing down a little bit and increased the idle mixture and voila! Runs a crap ton better. Still not super healthy feeling, but it's not having the crappy stutter anymore and I'm not leaning out as much, sitting around 15.5 (lean) at full throttle now. I'm going to pull plugs on my days off and regap or replace them as well as the fuel filter. I think I heard it making a weird sucking sound, couldn't pinpoint where the sound was coming from. Quote Link to comment
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