Hey guys, I went today to go dyno tune my 2000 SC max with an Apexi S-AFC and I was SHOCKED! On my first run, I did a base run and found out that I was leaning out pretty bad after 5500 rpms. So, I richened the mixture for my next run and nothing happened. It got even leaner! I was getting close to 15:1 A/R !! I was like What the Hell is going on over here! Then I was thinking to myself....could it be that my Aux. fuel pump and vortech FPR was not installed correctly since I installed the kit? I did two more runs to see if anything changed with the mixture and nothing did. By the way, I was at 300 fwhp running extremely lean at a mustang dyno. I was surprised to see those numbers cuz I was expecting like 280 fwhp. Just to let u guys know for those who don't know, A mustang dyno typically has about a 10-12 % decrease in dyno numbers compared to a dyno jet. So, I am guessing that I have higher numbers than 300 fwhp at a dyno jet. But anyways, back to my duno runs....Well, I couldn't figure out why my car was running so lean. I checked my Aux. fuel pump, which by the way has a 8:1 disc, and everything seems to be installed correctly. All the wires are where they are supposed to be and tapped correctly, so basically I have no idea what it could be. Could it be that my injectors are running 100% full duty? I have a 3.125 pulley, test pipe, y-pipe, greddy full catback exhaust, 1 step colder plugs, Vortech FPR and Aux. fuel pump, and now a S-AFC. I have most of the same setup as many SC maximas in here, but for some reason, I am the only one that is leaning pretty bad. I also checked my Aux. fuel pump power line (+ source from relay) with a test light and it was not lighting up. IF any one of you can do the same and see if yours lights up, let me know cuz of right now, I am thinking that this line isn't supposed to light up. It's the red power line coming from the relay to the Aux. pump (+). Since, I checked everthing up now, I won't know if I am still running lean or not until I dyno again....that really sucks! I had my settings at 39% low throttle, 40% high throttle, hotwire 4in 4out, and 6cyl w/increasing arrow. So, if anyone has any info on whatI can do about this lean mixture, please help me out. Thanx a lot, I really appreciate it.

~AC

ps. Do any of you know of a 95 nonturbo supra's injectors will work in my MAX? They are 315cc top feed, high impedence injectors. Does anyone know if they fit or if they are in any way compatible? Thanx.

 

You need a fuel pressure gauge.

 

What came of this? Did you find the source of your problem?

Regarding the Supra injectors: Maxima injectors are the side feed type, so you would have to change out the fuel rail as well. Somebody else will have to answer the impedance part of the question.

 

I thought 2000+ maximas had top feed injectors? I thought I read that 2K+ maximas had top feed, high impedence injectors. I may be wrong....

As for, my situation, I still do not know what could be wrong. Thanx to Kev, he is going to check out my setup to see if I installed everything correctly. Hopefully, it's just an installation issue. If not, I may have to go with a walbro pump. I will let u guys know what the deal was........

~AC

 

Oh, that may very well be. I was thinking of 4th gens.

 

I found out why my car was running super lean. check out maxi-overdoses thread : "I have been running super LEAN all the time. Need advice~ "


~AC