RotaryMelon

iTrader: (7)

So heres the deal..

I went to move my 85 RX-7 into the garage to do some interior work this afternoon.. but it wouldn't start!
It was making exhaust.. and cranking really fast like it was about to start, but never does....

I went and took a look into the carb to see what was up.. and it was absolutely soaked with gas.. the secondaries filled right up when I turned off the key..

After lots of mucking around we finally got it started.. I had a friend hold the secondaries open while I cranked and it managed to start.

Seems to idle nice.. I adjusted the mixture yesterday.. BUT
I decided to check the timing.. the leading on both rotors flashes nicely.. the trailing on rotor 2 flashes nicely.. but the trailing on rotor 1 only flashes momentarily.. not with the sparks as the other 3 wires.
I imagine something is wrong is the distributor?

When I rev it, it bogs at first, but then picks up..

I took out the spark plugs and the trailing rotor 1 plug was wet...
Its not firing!.. but the car still runs & idles nicely.. wow

Sorry for all of this..
Anyone have any ideas?

82transam

iTrader: (18)

Technically our cars don't absolutly need the trailing plugs to run, the leading plugs do most of the work, so that explains why it still runs...
As for why its not firing, have you checked all the usual suspects first? Things like how old is the cap/rotor, how old are the plugs/wires etc Check all that stuff first and let us know. I can't remember the last time I heard about a distributor actually failing...
I'm curious though, you said the carb was full of gas?! Other than the spray of gas coming out of the jets you shouldn't be able to gas just sitting in there (unless your looking through the float bowl's sight glass) you may have some fuel problems that are causing your plugs to foul....
Good luck

RotaryMelon

iTrader: (7)

I forgot to mention that the cap, rotor, NGK wires and plugs are all new.. HAHA!
And yes.. the secondaries actually fill about 1/2".. but not the primaries...I dont know what could cause that to happen

82transam

iTrader: (18)

Float could be stuck open in the carb, or your running too much fuel pressure (if you have an aftermaket pump)

trochoid

iTrader: (6)

Ohm that plug wire and check the pick up contact inside the rotor cap. It may have been bent. For the flooding, it could be the solenoid, a sticking float or the carb may be due for renewall.

hanman

ditto

Gomez

I had this exact problem a little while back. Turned out the rats nest pipe to the charcoal canister had rusted solid and the air horn on the carb couldn't vent. This resulted in a pressure build up in the bowls (when the engine was warm and shut off) that resulted in fuel being forced into the secondarys.

I realise that Aussie first gens have a much simplified rats nest, but this aspect of our cars is the same, I believe.

Pic below of where the rust had formed inside the rats nest. I cleared it out with some copper wire and she was all apples after that.....

Cheers.

82transam

iTrader: (18)

Strange that it would have filled with rust given that the rest of your rats nest looks very clean...

Gomez

I believe the car had sat for a while without being driven prior to my purchase of it.

The problem showed up within a week of me getting the car home.

RotaryMelon

iTrader: (7)

Ahh forgot to mention.. I had removed my rat's nest already

Gomez

And what did you do to the air horn vent that was plumbed into the charcoal canister? If you blanked it you may have inadvertantly caused the problem you now have.

The problem I had didn't occur all the time, it used to come and go.

RotaryMelon

iTrader: (7)

Can you show me a picture of what the air horn vent is supposed to look like and I'll see if mine's the same?

Gomez

Sure, here ya go.

This is the vent you want open to atmosphere (or better still, plumbed back to your charcoal canister).






Your carb will look a little different to mine, but that's the vent you want open.

Cheers.

RotaryMelon

iTrader: (7)

Thanks for the picture.. according to the rat's nest removal.. I have that vent hosed in as a crankcase vent with the purge valve

trochoid

iTrader: (6)

That works too, and you should tee in the charcoal canister, or the vent line to the tank if you've removed the tank.

RotaryMelon

iTrader: (7)

More straaaange problems..

I managed to start her first try tonight.. float levels are UNDER half... this time no flooding into secondaries.. Got it warmed up, and I was inside my house letting it run.. all of a sudden it stalls out.. Start it up again.. many backfires before it stalls out again.. then i'm unable to start it again..

i looked in the carb and opened the primaries by hand.. and what looks like smoke was coming out of the jets....


Idle set about 1100 to be safe... timing seems to be right.. (the trailing mysteriously works fine now)

Mixture is set....

What is wrong?!?!
I figure I'll just buy a sterling carb and hope that solves these problems...

RotaryMelon

iTrader: (7)

Forgot to mention... full tank of gas!

Gomez

Check to see if the return line to the tank is blocked. If you can blow down it and hear bubbles then you know it's clear.

Gomez

This fuel pressure one is a good possible cause too. You don't have a fuel pump from a fuel injected RX-7 in there do you??

If you have, then the increased fuel pressure can override the needle and seats and cause flooding into the secondarys.

trochoid

iTrader: (6)

Your idle speed needs to be 750-800 to properly set timing. At 1100 rpm, the vacuum advance has maxed out and is now getting into the mechanical part of, your timing is off the way you have set it.

If the float dowls aren't sitting at the 1/2 way mark, start with a fresh fuel filter, check the old one for debris. If that doesn't solve the problem run a can of Seafoam through the tank. Please note that the rear inline fuel filter is not the only one in the system. Where the hard fuel lines bolt to the top of the carb, there is a screen/mesh filter that surrounds each banjo bolt, along with another one under each of the needle/seats assembly.

On most of the carbs I've torn down for R&R, the mesh filters surrounding the banjo bolts are so plugged that they have collapsed and in some cases, split open.

GSL12a85

Ahh right right..... I figure I'll buy a Sterling carb... replace filters, and oil and all that other good stuff.. and re-set everything

this should have my problem solved, thank you all!

Gomez

I'm assuming this is a forum glitch and that you are really RotaryMelon....

Changing the carb might be a complete waste of time and money. I rebuilt mine trying to fix my problem (I wanted an excuse to pull it apart anyway!!), it's quite likely that your problem is not carb related.