yayforaddison

iTrader: (1)

I'll try and keep this short but give as much detail as possible.

This is my fourth rotary, but first carbureted car ever, so bare with me!

I live in KY and my Rx7 is back in Florida with my parents. I had my dad go look at the car FOR me and test drive it. Had the car towed back to their place until I could make it down. Well I went down and did some basic maintenance on the car (new NGK plugs/wires, water pump, belts, oil change, and other basic tlc.) before I drove the car. I crank it up and its only running with the choke on (about 90 outside back in Florida) until fully warm. The car was driving fine, until I would try and give it maybe 1/2 gas or about about +4k RPM's. Sometimes it would rev to redline, sometimes it would die unless I let off the gas, other times I'd have to pull the choke to keep it idling.

Brief history on the car. 56,000 original miles, original motor, just about all the maintenance history (mostly oil changes) since 79. Car sat for what I was told for about 10 years. Completely OEM down to the exhaust. The guy I bought it from got it running again (he had about 4 FB's at his house, so I assumed he knew what he was doing). Said he even cleaned out the tank and changed the fuel filter. Well it has a second glass filter under the hood and you can see tiny bits of rust making its way to it, leading me to believe the tank wasn't cleaned. Car barely had any gas to I added about 5-7 gallons of 93, and some injector cleaner. Still no luck. Unhooked the fuel line under the hood, put the line in a bottle, and its pushing lots of fuel when the motor is cranking. I bought another new OEM fuel filter to start with since I got back to KY, but my dad is taking his sweet time to install it for me while I'm back in KY...

Shew, I hope you guys are keeping up!

My questions:
Since I'm new with carburetors, does this sound carburetor related? I did follow instructions on here with adjusting the mixture screw with no luck.
Maybe a weak fuel pump?
I wish I could say this was fuel filter related, but it isn't doing it every time, could I be wrong?
Thermal reactors?
Or am I way off?? Ignition, timing, emissions???

Hope you guys can can at least point me into the right direction! I'd hate to spend loads of money on one area to find out the problem is coming from another.

Arcolithe

sounds like my first encounter with rust 5 months ago.
take off the air horn on the nikki and see if the fuel bowls are clear. Those tiny jets will get clogged with the finest grains of rust possible.

Arcolithe

remember how rusts work. Once rust, will continue to rust.

If you live by the beach there's a famous guy named shrek that helped me set up my fuel/carburetor and fix the rust issue.

gonna edit some pictures so you know what im talking about
fuel bowl:


and air horn is on the top:

and oh god that nikki carb pic is so damn clean.

yayforaddison

iTrader: (1)

Oh, so that tiny bit of rust I saw in that second fuel filter has probably clogged a jet in the bowl?!

Does this require a carb rebuild?

The car is basically in Sarasota, FL. Or about an hour south of Tampa, if that answers your near the beach question.

Arcolithe

doesn't need a complete rebuild, but you need to remember how to disassemble and reassemble things.
as long as you don't mess around too much with the accelerator/choke cable you should be fine. Also if your carburetor is de-emissioned would be another thing.

If I were you, I'd do some research for bigger nikki jets, which means you'd be using up more fuel but prevent the risk of rust clogging. This just means that said rust will be going into your engine and causing problems there (just decrease it's lifespan generally.) My car ran fine with scraaaatched housing, but after a rebuild and new housings it's driving super peppy.



You can easily clean those jets out by:
1. unbolting the air horn (may be easy to disconnect the fuel inlet first)
2. gently removing the cable bracket to lay to he side
3. remove air horn

now you can either spray carb cleaner with a thin nozzle into the jets until you see it come out the other end, or you can unscrew it and clean it out proper.

for the love of god don't drop any screws or bits into your intake manifold. If you haven't done any sort of mechanic or delicate work, this may not be the job for you.

someone else might be able to post wiser advice, do remember my join date is "Jul 2013"

yayforaddison

iTrader: (1)

I usually do all my own work on my cars and I've been working in a shop for the past few years. Long story short, the oldest car in our shop was an 08, and I've never owned anything older than an 87, so carbs are still new to me. In other words, I feel safe enough to work on it myself thanks to your help with this carb/jet info, but I was lost before.

I don't plan on doing any emission delete or bigger jets. I'll try and just clean the jets and keep the car as original as possible. The car is in great shape and doesn't have any mods, so I want to try and keep it that way

diabolical1

iTrader: (3)

congratulations. sounds like you have something quite special.

it may not be ALL of you issues, but this pretty much gives you a place to start looking. clean the tank and refurbish the fuel system. if you saw rust in the filter in the engine bay it means that the main filter is in pretty bad shape. the pickup filter, even worse. the intermittent fuel starvation you described is typical for this situation. cleaning or rebuilding the carbie will do very little if you don't deal with what's happening upstream first.

i think the member, Cookboy, has a thread that can help you out. search for it.

yayforaddison

iTrader: (1)

Thanks. I'm always on the hunt for a good find. Car is in amazing shape outside of this small running issue. White on brownish red, 4 speed manual, and no sunroof. A combination I fell in love with!

I definitely plan on cleaning the tank now. The last thing I want is a bunch of little rust making its way to the motor and scratching it to death. I have a new OEM filter to install behind the driver rear wheel afterwards. The car is sitting down there now without my help to get it on the road however, so unless my dad would like to get his hands dirty, I have to wait to tackle the car again. I hope the idemitsu I put in the tank protected the motor from any little bit of scratching the tiny bits of rust may have caused!

Hope after a good tank cleaning, fuel filter, and cleaning the jets, it'll make a 1,000 mile drive back to Kentucky!

I'll have to read up on this "cookboy's" thread until then!

Thanks again guys!

Cookboy

iTrader: (10)

It's not mine, but if you search "marine Clean" you'll find what I think is an excellent tank cleaning thread. Once the source is clean, a lot of other little problems magically disappear.

diabolical1

iTrader: (3)

ooops! guilt by association, i guess.

yayforaddison

iTrader: (1)

Well now I feel a little better about creeping all over and reading all your threads with no luck, Cookboy :P

Guess its time to clean the tank and jets! It may be a month or two, but I'll try and keep you guys updated. Thanks again!