wankel=awesome

I need some help in my local area or at least close to me with my Rx7's. As some of you know, my red se was destroyed this summer by a soccer mom on her cell phone... I found a rust free and collision free 85 GSL with a running 12a in it ( massive lean condition at low throttle angle affecting mostly one rotor) that I cant figure out wtf is wrong with.

Ive rebuilt the carb, (Rb 465) put the engine in time, tried jetting the carb, done compression tests, vacuum tests, all new ignition, fuel pump etc.

Compression read outs were:
(112)(115)(112) R1
(116)(114)(113) R2

Vacuum results were a choppy reading between 12-15 inches when referencing the brake booster bung on the RB manifold.

Ive tried working with holley, RB, local shops and forum members on this issue, but I cant find anything wrong with the carb.

At higher RPM's the issue simply isnt there, although power seems to be low.

Fuel pump is a solenoid in line doing a constant 6 psi@35 gph (no return)

When adjusting the idle mixture, R1's mixture screw is turned in almost closed for the optimum idle quality, while R2's is nearly two turns out.


RB says my motor is shot, so I want to fix it. But what is wrong with it? And if it is in fact shot, who can help me swap my GSLSE's engine and trans to this GSL? No shops in this area will even touch it, been calling aroud for nearly 3 months.

13x

are you running a wideband for each rotor?

84stock

iTrader: (5)

add a 1/2" open spacer

wankel=awesome

I dont think the RB carb was designed to run a spacer, and I think that would further hinder its already woeful torque production. It just has 0 power below 3k rpm.

As for the wideband, no. Im reading sparkplugs every other day or two of trying to run it. I took my gslse for a drive tonight (despite being smashed) and its like driving an engine 10 times the size of the 12a.

This is a BRAND NEW rb 465 with >500 miles on it.

If nobody can figure this out soon im scrapping both cars and forgetting the thousands wasted on the rotary engine. The engine isnt blown, RB denies the carb being at fault in any way, wtf else could it be?

LizardFC

iTrader: (1)

Without a wideband you're shooting blind, simply put. You can't just put aftermarket carbs and fuel pumps on a car and expect it to run right. Those compression numbers are really good if they are accurate, nowhere NEAR "shot." Also, not sure how much fuel the 465 likes but 6 psi sounds like a lot. Get a wideband (or two if you're running a separated manifold) and tune it properly.

wankel=awesome

The RB 465 is "pretuned" for the 12a if you meet the 6 psi@20 gph requirement for the fuel pump, and the company refuses to work with you if you change the carbs jetting, or any other "tuning" to the carb. Ive tried jetting the carb up nearly 10 jet sizes and the lean condition still exists. And when i say lean, I mean the car sputters out and nearly dies.

DreamInRotary

iTrader: (49)

May I ask how you can claim that it is affecting mostly one rotor? That leads me to believe that you have a separated manifold (header) and you can see one side glowing more than the other?

LizardFC

iTrader: (1)

It can sputter out and nearly kill the motor if it's running too rich as well. Typically you can smell fuel in the exhaust in that case.

rotaryjunkee

Wankel=awesome, still having problems with the RB Carb. I thought you had it all figured out on your thread "RB 465 odd symptoms". You had definetely opened up my eyes on tuning the Holley Carb, I bought a book on tuning and modifying the Carb and got my RB 465 going good and strong. I ended up installing a 8.5 powervalve and 51 main jets with idle set screws at 1 3/8 turns from closed. Now she runs like a champ. Hope you get yours going.

wankel=awesome

My problem simply isnt the carb, its something else. And I know its a lean condition on one rotor because of the white and burned spark plugs on r1. this engine dies unless im pumping the accel. to squirt excess fuel in, and smelling gas at the tail pie is standard for all my rx7's, including my gslse.

jetting up 10 sizes helpes, but its still not right. Its powerless down low, and too rich up top that way.

The car just feels like it weighs too much for the engine, and I cant explain why. It does not exceed 80 mph floored in top gear. My rotary is why the stigma exists about them. Makes no damn sense and makes no power, getting 11 mpg while doing it.

craaaazzy

iTrader: (9)

Have u looked at the intake itself?

wankel=awesome

Its a new intake mani, and a new intake gasket. Im not sure if perhaps its leaking between the primary ports or something.. I can spray carb cleaner all around the mani and get no rise in rpm

flight_of_pain

In all honesty, before you get all worked up, throw a known good stock nikki/manifold on it and see what happens. Hook up the fuel lines like stock and use the return.

Isaac

wankel=awesome

I would, but I cant find a nikki

flight_of_pain

I would bet there are multiple people local to you that wouldn't mind loaning you one for some testing, have you checked in your regional forum?

Isaac

wankel=awesome

Yes, the only "local" rotary guy is 2.5 hours away and he wont part with a intake mani+carb for anything less than 700$


Can anyone help me swap the SE's engine into my GSL? Its such a strong runner and been so reliable for me. Theres gotta be a way to swap it over...

flight_of_pain

Slot the motor mount bar, and the -se block will bolt right in. Going price around here for a nikki is about $50, might be worth it to you to hound the FS section a bit.

Isaac

Mazda RX-7 EFINI TYPE

Ya. You should definitely try a nikki before doing something that drastic, especially since your motor has good compression. At least it would help you narrow down your possibilities.

wankel=awesome

Is there nobody on here that can help me with the swap? I have money to spend on the swap, and it needs done badly.


Also I scored a nikki mani for a 85, but still no nikki. If anyone has any kicking around id really like to buy it lol

wankel=awesome

Was out last night doing some work on the car desperately trying to get it to start to take me to an interview, and noticed something strange. While the engine is idling, when I turn R1's screw in to clean up the idle a clear hissing noise is apparent from the DRIVERS side of the engine bay near the dist/PS area. It was dark and cold, so I couldnt get a really clear look, but wtf could be on that side of the engine leaking vacuum? Any advice would be great.


Edit: Vac advance is hooked up, all new vacuum lines, the sound seems to be lower than there as well.

KansasCityREPU

iTrader: (9)

When you say you turned R1's screw in, what exactly are you turning (pic)?

wankel=awesome

the idle screw on the primary side of the holley metering block, the runners are separated so the idle screw facing the firewall is r2 idle mixture, and the one facing the front of the car is r1's idle mixture screw.

on a RB holley anyways, using the rb manifold

LizardFC

iTrader: (1)

I'm guessing that idle screw works as a bleed like the Nikki. When you turn it out so far, you can hear the air escaping. It's not a problem in itself, but if you're having to turn the screw out that far then the mixture is pretty out of whack.

wankel=awesome

Exactly, one is turned in 1/4 turn from totally shut, while the other is a 2 full turns out.

By that I mean R1's preferred idle mixture is 1/4 from shut, R2's is 2 full turns out.

RB maintains that the problem is not the carb. And at this point Ive even rebuilt the carb, didnt see any improvements with this.

THEWITCHKING

iTrader: (3)

Weird problem. Sometimes I have a similar issue where I'll sputter at take off and sometimes shifting through gears, but I think it's because my carb needs a rebuild. Stupid question, but have you replaced your fuel filter? Sometimes it's the simple stuff that is easy to overlook that you would never think would be the problem that is the problem. Btw if you're gonna scrap your SE I'll buy the ecu and harness off of you. oh and oil pan and front cover. For the right price of course.