Today just for fun i finally hooked up the boost controller vacuum lines to run more than base boost. I can see how people are blowing their motors.

With the base boost and base greddy maps the car runs a nice 10.5-11.2 A/F under boost, with a max boost of 5.8psi... but on hotter days it has trouble going over 5.0-5.1psi.

Anyway, I turned the boost up. At 7.5psi the A/F was 13.9:1 by redline. It was rich as normal down low, but 1000 RPM before redline it went into the high 13's.

At 6.5psi I was getting 13.2:1 by redline.

Both of these of course are NO GOOD.

5 psi it is for now. I was gonna wait to touch the fuel system till the car is running on the new motor and FCON... however I feel like I want to play with it like this for a while, so I might go ahead and put in the pump and return system and ****. We'll see what I got time for this week.

I got a race this weekend tho, and I want to get this car running 7.5 psi... I got ALL the fuel system parts here, even some new rails and what not... just gotta decide what I need as a bare min to put in there for now just to get the extra 2psi safe.

-Charles

 

Thanks for the advice Charles. I am holding off turning the boost up until I have more information. My goal is to get about 7 - 7.5 so what you find will definitely help. TIA

 

Phunk, the bare minimum is just to pop in your Walbro 255. You might run rich across the board..you might not...really depends on your car.

With just the pump, i was able to run 9psi in the 11.5:1 range all the way to redline, also retarding timing by 6 degrees at redline.

When time permits, I plan on installing the FPR and return....going to leave the stock fuel rail for now.

 

You can raise the boost a little by dropping in a Walbro 255. At 7psi my A/F would rise to around 12.0, and at 7.5psi it would climb to 12.6. Adding fuel in the appropriate cells didn't help so it was obviously the fuel system holding it back.

For $100 and 1/2 hour install, it's worth it, if only as a band-aid until you get the fuel system straightened out.

Looking forward to your results with the FCON...

-D

 

GQ beat me by 1 minute...

Get back to work

-D

 

hehe....I also added fuel via eManage...maybe that helped as well.

 

thanks guys... ill let you know what happens i might throw that pump in there tonight and see what happens. i still have not added the ignition harness to the car... but the car also only runs on 100 octane gas... so im not too worried about it. But I do think that I should put in some colder plugs now... im still on the original 23,000 mile old plugs.

The nissan dealer has one heat range colder factory plugs for it... so I might just get those.

-Charles

 

Becareful not to get any gas on the o-ring seal, so it won't sweal, and you can reuse it

 

so those of you who just dropped in the pump ended up needing a retune than?

 

Mine require just a bit of tweaking of the existing fuel map. I leaned it up just a tad in the middle of the range.

A couple of people have good luck with just the pump...but others...the car was running way to rich and they needed FPR's.

I think you mentioned you were under time pressure, so just drop it in and see what happens. Regardless, you'll be able to safely boost more.

Also a good idea to go get a new o-ring gas tank gasket, just in case you warp the existing one. Like ACP said, if you get too much fuel on it, it will expand, and be worthless. But it would suck to do the job, and then realize you need to get that gasket, which is almost always special order...couple days max.

FYI..if you end up a jam, I have an extra one brand new in my garage...I could overnight it to you.

 

thanks man... think im gonna go try it out in a min and see what happens.

-Charles

 

wow... wish i knew not to do this on a 100% full tank.

there is now race gas ALL OVER. Unfortunatly the gasoline also ate the coating off the tank... so now the gas tank is nice and shiney bare steel - soon to be rust.

Also... getting that pump assembly out of the tank was a huge fiasco. I am concerned about the level sensor being bent now... i might buy a new assembly.

ANyone have pics of their fuel pump assembly out of the car so I can compare and make sure my sending unit is not all bent out of shape?

 

Phunk...crap...I guess we should have mentioned that the service says to make sure the take is at minimum, only 7/8 full...less is better.

The the fuel level unit probably fine. It has a couple of bends in it already. The only way to know for sure is just to reinstall it and check your fuel level. I think you're fine. I banged mine around really good, and nothing happened.

 

yea after taking a good look at it i think that its fine, doesnt appears to be bent out of shape at all.

im working on trimming the plastic to get this pump to fit in there... i think the rubber insulator is gonna have to stay out.

the large assembly o-ring i think is fine... since you guys said it tends to get damaged from the gasoline i pulled it out immediatly and washed it off with water and wiped it clean... appears to be good.

 

oops i loose... the o-ring swoll up haha.

 

Wow really ? You followed the service manual for removal of the assembly, and released the full pressure ?

Here is a link to a post I did on the fuel pump assembly, hopefully it will be of some assistance
https://my350z.com/forum/showthread....threadid=76132

That stays

 

hello... i didnt follow the manual i just went in there and did it. the only reason i got gas all over is cause the tank was full and the fuel level was higher than the pump.

i got it all back together, i managed to reuse the large o-ring. there is no leaking, i got it in the groove well... it had just barely expanded and i was able to work it in there. the fuel level gauge is working fine also.

the rubber insulator is gone... this fuel pump was a little bit taller and it was hard enough to get the plastic cap to hold it in already. i trimmed the 4 plastic tabs off the bottom of the pump to help make it fit. its a very snug fit and im not worried about it.

i was just out boosting, the car seems to run exactly how it did before, just not as lean above 5 grand even at 5 psi. at 7 psi it seems to go to a 12.7 or so A/F... i would like it richer than that I might see if I can get more fuel to come out with some e-manage tweaking. i want to get 7.5 to 7.8 psi running in here.

i might try putting in the regulator if i cant tune it richer.

i need to go clear the e-manage out now and load in a copy of the base greddy map to start from. I will probably strap this car on the dyno tonight so I can have logged A/F for several passes to check for consistency. I dont want this thing to lean out in a race. Maybe ill take it to the track tommarow on the drag radials.

-Charles

 

wow I just dynoed this mother****er... im gonna make a new thread to show the results.

im very pleased.