FB II

heres the deal; i bought a holley 600cfm w/ racing beat manifold from a guy in florida. it was setup and tuned at a rotary shop. (fogot the name, have reciept somewhere). anywho, it was tuned for the exact setup i have. full exhaust, no emissions, no cats, etc.. SOOO; i got it on a couple days ago and then i got my fuel system setup yesterday and today i tried to get it going. first problem i had was the holley pump i have had for a long time (just never installed) lies!!! hahaha, the "in" and "out" sides are flipped! i was pushing the fuel back to the tank!!! AHHH, flipped it around and BAM. fires right up. i had some regulator problems but now the pressure should be good. (need a gauge) i know i know, but it has to come in the mail as no fuggin shop here has one! AHHHHHH! tonight i got it to idle beautifully at about 1000rpms. i can make it go lower but when i let off the gas it will sometimes try to stall. i've only driven it a short couple of miles but immediately it felt a hundred times better than my modded nikki. it feels even more streetable, being as i barely have to give it gas and it just goooes i did get on it once pretty hard and holy mother of hell.. i went through the gears faster than ever. it felt sooo good, BUT here's the thing.. going from second to third has a slight stumble when i drive very lightly, then it kicks in real nice and pulls well. i did some reading and maybe it seems it could be running lean? it does pop on decell. any holley guys have some advice? i'm completely used to a nikki, but the little bit i have messed with of this holley so far has made life easier. i love how everything is setup sooo simple! thanks guys, sorry for the novel.

mwatson184

Don't forget there is an idle mixture screw on each side of the metering block, and these must be set the same or you can have some funny things happen.

One time I had a friend adjust my carb so it would idle and he only adjusted one of the screws. For the next few days during warmup my car would start and only run on one rotor for the first 20 seconds or so.

Does it stumble right when you get on the gas after shifing from second to third?

FB II

YES, that is it exactly! and actually it does it going from first to second as well. forgot to mention that. like a slight hesitation.

mwatson184

So it only happens when you are not getting on it though? Just normal driving between shifts? There are 2 holes on the accelerator pump for two differents settings. Try setting it to the setting that will give you an earlier pump shot. If after that you have a hesitation when you mash on the throttle, then you will need to get a larger accelerator pump cam.

mwatson184

or larger shooters, that would probably be a lot easier

heb09

By the same u mean the same amount of turns out from tight?

heb.

Rx7carl

Depends on the carb. If its a 4160 From RB, then theres only one idle circut. 4150's have the dual idle circuts, and dual metering blocks.

Your problem to me sounds more like the AP needs adjustment. Whats the clearance between the lever and arm? If you dont know how to adjust it, ask. Remember, before throwing parts at a problem, you must first define it.

FB II

carl you are da man. ok on my holley i have a little screw on each side of the metering block. i messed with it a little today and it didnt effect my idle at all. ??? but when i went to drive i flooded out. hahhahah, well, it's actually not funny cause i got stuck kinda far away. it was wierd. anywho, i didnt get a chance to look at the ap. anyone got a pic. this holley is still very new to me. oh and carl, the clearance between the lever and arm? i am asking. i sure as hell dont want to mess anything up. thanks guys! you and watson are of great help!

79+80+84_rx-7

well... Are you sure the wires on your holley fuel pump arent backwards? Causing the pump to pump the wrong way? (I dont think holley would mass produce something backwards....) Just a thought I'd mention that... not that its a problem or anything....

Laters, Andrew

FB II

oh LOL, i found out why that happened. it wasnt the wires or holley making it backwards. the plate has been removed before and accedentally put on the wrong way. :-P

Rx7carl

Ok, heres the procedure for adjusting the pump. Lets first get familiar with teh parts. Theres a lever on the bottom of the bowl that actuates the AP plunger. The end of that arm contacts a screw/bolt head that faces upside down. On that bolt is the override spring, and talso connected to it is the actuating lever. Got all that?

With the throttle held closed at idle, hold the bolt head with a wrench. Then turn the nut, adjusting the bolt down till the bolt head just hits the AP lever (zero clearance). Then open and hold the throttle wide open. Now grasp the little AP plunger lever and make sure it has a little more travel (.015-.020 is spec). This ensures that you dont bottom the plunger and possibly bend the linkage at WOT. HTH

Rx7carl

Ok, then you have dual metering blocks? You must if you have a small flathead idle mix screw in each one. Turn them in GENTLY till they seat, then back out 1 1/2 turns. Thats the starting point for mixture adjustment.

FB II

well, i have one metering block, but it has a screw adjustment on each side at the bottom. (the metering block goes between the float bowl and the barrells right?)

FB II

one more major question, i got an email from watson saying i should look for a vaccum leak. now on my nikki, i had a vaccum leak. a very bad one, and i think it was coming from the intake manifold to block gasket. i am an idiot because when i removed the stock stuff i thought the gasket looked damn near perfect still (it is only a couple months old and the car didnt run much during that time). but, the holley will hold a very steady idle at whatever i put it at, BUT watson noticed that i said when i turn the mixture screws... NOTHING happens at all. sound like a vac leak??? hmmmm. would this cause everyything else to be out of wack?

FB II

allllllllllllllright; "update" ok, tonight i got home from work and decided to attack the vaccum leak. i ripped the carb and manifold off. cleaned everything and then used some liquid gasket and made my own. shouldnt leak!!!!! ahhhhh! then, i adjusted the floats. i set it to where when the fuel pump is on, it just baarely drips out the sight holes. next, i messed with the air fuel screws and turned them all the way in and then 1 1/2 turns out. and last; i opened the secondaries up just a tad and backed off of the idle. the master tech at my job says that will help the carb to only run on the idle curcuits instead of idle curcuits and partial throttle. because my primaries were pretty damn open even idleing at 800rpms. he said this should do the trick. tomorrow i will try and crank it! anyone think i should adjust anything else? lemme know now. WOOOOOO!

red13brx7

I have a little stumble in mine, but after tunning it goes away. It is just your air flow mixture. Needs just a little more adjusting.

FB II

we'll see come tomorrow afternoon! i plan to adjust the accel. pump too as per carls info. yipeee!

-the zacster

kettlman

iTrader: (2)

i'm wounderin what kind of engine (interior mod wise) you got? do you know what size of jets you have?

Rx7carl

Well? ^^ Free bump

mwatson184

Instead of opening the secondaries like you have done, you can drill a small hole in each primary butterfly. Only do that if nothing else works though.

FB II

sweet, but i couldnt get it to crank today i had made a gasket out of high temp rtv and i guess that just wont work. or maybe i didnt use enough. it leaked a little gas so obviously there was a serious vaccum leak. damnit, i used it on my old manifold. i dont wanna wait on the rb gasket. lol. guess i have to though :/ any suggestions?

Rx7carl

Yea, the Holley carb builders do that for race carbs on the oval track cars that dont have to idle low. I wouldnt do that for a street carb though.

Zac- wait for the gaskets. RTV isint very happy in a fuel environment.

FB II

amazing thing today. i called up the mazda dealer near me, and BOOM! they have one intake manifold gasket for me! $6.50 !!!!!! oh well, about the same to be shipped from somewhere else. LOL. i will pick up it up early tomorrow morning and then slap that **** on! should i be using a special gasket though with this rb manifold? or will the stock one be ok.

79+80+84_rx-7

stock will work....

Rx7carl

Put the gasket up to the RB manifold and trim it to fit their ports. They are different than the ports on the stock manifold. Try it and youll see what I mean.