DustySkunk

Alright. So I have a 79 rx7. I have only had it for about a week and a half. I'll start on the day I brought it home.

Turn ignition on, pump accel pedal twice, pull choke crank car. It starts easily but creates a HUGE plume of white smoke which dissipates with 2 mins of the car idling. Reminds me of how a piston engine does when it has leaky valve guide seals and oil leaks into the cylinders when the engine is at rest.

Car accels and drives fine till the choke goes off. Once this happens the idle gets rough and the car fights driving at a steady speed however it still accelerates great.

It makes a 1.5hr drive home just fine.

Get in it the next day and drive it around for 45 minutes does the same as before but is a little smoother all around.

Take it to work on day 3. Chilly 40degree morning. I go about 12 miles or so before stopping for a quick breakfast and the car is a bit sluggish to start up but does and continues to drive fine. It was running even smoother. for another 5 miles or so.

Then the problems begin, at 75mph I lose power. The engine is still running and firing but there is no power. Seemed like it was out of gas even though the fuel gauge was just under 1/4. Coasted to a stop on a steep down hill circle ramp. Gave it a few seconds and tried to start it, it started right up and ran just fine for another mile then did the same thing. This time it wouldn't restart.

It hasn't fired since.

I pulled the fuel feed line from the carb and put it in a cup and it filled an 8oz cup in just a second. Plenty of Fuel.

Pulled the spark plugs. The trailing plugs are pretty darn clean. The leading side ones are a little cruddy. They also have better spark than the trailing ones. (all 4 plugs are the same part #)

This led me to compression. I don't have a compression gauge but it sounds like "PSH psh psh psh psh psh" I had both leading plugs out when I was listening too/trying to feel the pressure. I made the mistake of leaving the trailing plugs connected. This allowed some spark and one of the cylinders actually fired when I was doing this. (btw it was SUPER loud)

One thing I noticed today is that the oil seems to be disappearing. Also the engine is beginning to resist turning over with all the plugs in it, it will only turn over if at least one spark plug is removed from each cylinder.

I don't really know what to do anymore. I think it may have even locked up on my last attempt tonite.

DustySkunk

How about this. Would you guys bother rebuilding the 12A or swap up to a 13b?

diabolical1

iTrader: (3)

welcome to the board.

have you tuned it up since your bought it? the fuel filter probably needs changing. filling a cup is okay to confirm the pump is working, it doesn't confirm that the filter is good.

your 12A vs. 13B question is not THAT simple because of the fact that 12A parts are finite right now. you'll have to answer some serious questions for yourself before the decision can be made.

DustySkunk

Previous owner replaced: Fuel pump, Fuel filter (quite obviously new when you see it under the car), some fuel lines near the tank, Plugs, Points, Belts, Battery, Tires. Only put 500 miles on the car during that time.

Well if the 12A parts are finite this tells me that it will be more expensive to rebuild the motor than it would be if there weren't so limited.

Wouldn't that be another positive for swapping for a 13b?
What other serious questions are you referring to?

diabolical1

iTrader: (3)

have you tried swapping plugs and/or coils around?

how much oil are we talking about?
what shape is the battery in?
how does the engine feel when turned by hand?

diabolical1

iTrader: (3)

building a 12A is not more expensive, but if you find yourself in need of hard parts (rotors, housings, shafts, etc.) then what's out there is pretty much all there is. doing it as a one-time shot is not going to be a big deal, but if you find yourself having to do it more frequently, then ... you can now see why it might be a problem.

the questions I was referring to are basically what costs and complexities are you willing to undertake for the swap. it's really not a complicated swap, but it will require resources in one form or another (money, time, a third party, etc.). a 13B will need: mounting, intake, at least a partial exhaust and possibly wiring (depending on how you choose to run it).

DustySkunk

I haven't tried swapping the coils around, I didn't know that was an option. Though they look the same I wasn't sure if they actually were.

I'm not really sure about the oil situation. I'd be guessing at best.

Battery is having a rough time with all this cranking and charging and cranking and charging. But it's fairly new and seems to gather charge pretty well.

It seemed to turn without too much force. Granted it didn't just spin around, there was some resistance. It just was a fair amount of force required but not difficult.

Today I went back out and messed with it a bit, I was gonna try the atf trick. So I removed the air cleaner and started looking down in the carb and decided to flip the butterfly valves by hand and be damned if fuel didnt splash up. I don't remember any other carb'd car I have had holding so much fuel in the carb. It splashes around when I move the butterfly flaps. That cannot be normal can it?

Flooded? maybe drowning?

Mps_hell

How much oil is missing? if its only a little it is normal.
The carbi should have some fuel in it, try pulling the fuel line drop it in a tin pull the plugs crank the engine for I sec, have a look in the tin see if the fuel is clean. Now with the fuel line off crank with the plugs In if it starts(might be ruff and smoke) you got a flooding problem. If it is still hard to start when the plugs are back in dont force it. It might be something bad

DustySkunk

I got a backfire out of it this weekend. Nothing else. Fuel is clean.

The combustion chambers seem to be very very wet. I still think it is very very flooded but it doesn't seem to be getting better.

diabolical1

iTrader: (3)

have you tried leaning out the mixture?

I seem to find myself asking this question to new Gen I owners a lot these days, but what kind of fuel pump is currently in the car?

DustySkunk

The oil does not smell like gas.

I don't know what kind of fuel pump it is. I am guessing it is above the fuel tank and I cannot see it to find out what kind it is. I know it was changed before I got the car and has less than 1000 miles on it. I also know that it isn't secured very well. Fuel filter is also new as are the rubber fuel lines near the tank.

Fuel is also clean, no particulate matter noticeable.


At this point I'm ready to just throw it in storage and cancel the insurance and wait till I ahve more time to mess with it. more time, or a garage. I would like to just rebuild the motor that's there, but I've never done an engine rebuild and especially not a rotary rebuild. Though I was successful in changing a piston in a 1988 kawasaki ninja 600RR and it ran great afterwards. (Mostly because the piston no longer had a hole in it.)

diabolical1

iTrader: (3)

find the pump. I doubt it's above the tank, but I suppose people have done stranger things. however, the previous owner may have installed something that is simply too much for a carburetor. it seems to be relatively common.