RRTEC

iTrader: (13)

Ok i adjusted the timing, and replaced the fuel filter, cleaned the K&N, Ran fuel injector cleaner, passed emmisions (barely) but my fuel consumption is rediculous! I am getting 60 miles to a half tank! HELP ME PLEASE! I cant afford to eat if it goes on like this!

$100T2

iTrader: (1)

Lighten up on the right foot, shift below 4k...

And I was told by a by a guy that really knows rotaries to NEVER, EVER run fuel injector cleaner... He said it ***** up the o-rings...

RRTEC

iTrader: (13)

great.....I hope they are ok....

Rotory

iTrader: (1)

hey are you from Franklin city or franklin county?? i live in tennessee too

ilike2eatricers

Anybody else heard anything about this?

5 point whoa

you can run mystery oil in it, and it cleans it out safely, but I've heard not to run any cleaner through it though

Aaron Cake

iTrader: (1)

Don't worry about injector cleaner. Doesn't do any harm unless you run it in MAJOR (ie. half a tank) concentrations. I run a bottle with every oil change.

60 miles to half a tank is crazy....Are you sure you don't have fuel leak? If you are THAT rich, your exhaust is probably glowing red, and your car trailing a cloud of black smoke and soot. Probably doesn't idle either....You need to do a full tuneup, and have your injectors cleaned/flow tested.

cbrock

iTrader: (1)

The first 1/2 the gauge seems to drop pretty fast regardless. Fill the tank all the way up, keep track of the miles and fill it all the way up again. Now you know how far you went on how many gallons of gas. Figure out your actual MPG before you start to worry.

scathcart

It has nothing to do with o-rings. The "do not run carb cleaner in a rotary" comes from the days when 6mm carbon apex seals came stock.

Dougster

Yep dig deeper, how is your cats condition? Check and or replace plugs...Good luck. Oh, what year & miles on it?

$100T2

iTrader: (1)

Aaron, I'm talking about a fuel injector cleaning service, like at Midas or whatever.

Rotory

iTrader: (1)

That doesnt sound like what you were talking about. You said "NEVER EVER run fuel injector cleaner". That sounds like the stuff you put in your gas tank to me

Aaron Cake

iTrader: (1)

Injectors should be cleaned by removing them from the engine. It's the only way to do it "right".

scathcart

I used to work at a oil change, I know how this works.

Its a 2 or three part system; 3 additives.
They dump one fuel system cleaner into your gas tank.
They dump one decarbonizing agent (or something) into your oil filler pipe).
Then they hook up a regulated vacuum canister to a vacuum line, typically the PB boster vac line. Then , you start your car, and they adjust a needle valve so that vacuum can be maintained while fuel system cleaner is drawn through the manifolds.
The engine bucks like crazy if you run it through too fast (open the valve too much, creates a vacuum leak which causes bucking), and the huge amount of fluid going through makes the engine essentially run extremely rich.

The reason they say it to do it is as listed above; where it would dissolve the older 6mm carbon apex seals.

I have done the treatment, leaving the oil part out, to a couple of my RX-7's. All it does is remove a minute amount of varnish and gum and carbon from the intake tract.
It is more designed for piston engines, where removing these deposits from the intake tract improves sealing at the valve seat. (deposits on the valve seat don;t allow the valve to properly seal.)


I personally don't recommned this service for rotaries for simple reasons: we don't have to worry about valves seating for compression, and you can get the exact same result by dumping injector cleaner into your tank for a fraction of the cost.

RRTEC

iTrader: (13)

Ok I have an 87 7 with about 30k on the mazda rebuilt, the whole exhaust is new from racing beat including cat. is is possible the o2 sensor is bad? would that increase fuel consumption? The car occasionally blows a cloud of fuel vapor smoke on heavy shifting from 1st to second gear. It idles ok after tps adjustment but i think i may need tio replace the tps all together. I passed emmissions here in williamson county. that's hard to do. i'll keep trying and i'm gonna get the injectors flow tested.

Phu5ion

Have you checked your plugs yet? That's something small and easy that could get overlooked, and it could also lead to poor mpg's. I should know, it happened to me.

skydivr73

Check your plugs, wires, and o2 sensor. I replaced my o2 last week and now I am getting 7 more miles per gallon than before with no other changes. other than that, it would seem that it is too rich to even run at 60 miles a half tank. But since you have a new exhaust and a rebuild, I dont think that your o2 could have gone that far downhill so quickly, unless the wiring is broken

jon88se

I bet it's just your GAS GUAGE...they are notoriously bad in these cars...road and track tested their TII when it was new and their gauge ran down to half after only 50 miles of driving...