Ta-Aikah

I've been trying to get my stock port, 79 Rx7 with a 12a to run for SEVERAL months now. I swapped from some unknown carb from some unknown rotary application (Weird Carb: https://www.rx7club.com/new-member-r...e-got-1127530/) to a weber 45 dcoe. All of the jets are close to the averages everyone uses, and the times I've gotten it to run it's sounded pretty smooth. (Even left the plugs a nice shade of brown.)

I am at a loss for what else I need to do. I'm fairly certain I have no vaccuum leaks. I cleaned the carb a little while after I got it, so that shouldn't be an issue either.

Today, I changed the oil because I let it sit flooded and got gas in the oil. I put some oil into the intake ports and spark plug holes and cranked it around like that. Then I put the carb and the intake back together and on the engine. Hooked all the lines up and everything. Gave it a little shot of starter fluid and it fired right to life and went up to 3k RPMS. After turning the idle down a little bit, I noticed the very high idle was because the throttle linkage was getting caught. Once I backed that off, I tried it again in the same way as I did the first time, and it tried to rev a little as it tried to start but then it died off. I haven't been able to get it to run again since.

I want to love the rotary engine and RX-7s, but this car is killing me. Any help you can give me to shoot me in the right direction would be immensely appreciated.

Thank you

JOE68

new weber ? .... check your idle jets ...spray some carb cleaner

Ta-Aikah

All of the jets are as clean as possible. Tried that a couple times already.

JOE68

can be so many things..... since u let it sit flooded you may hav a stuck apex seal... pour 3 cap full of transmission fluid and turn the engine by hand (rachet socket)..let it sit overnight...

Ta-Aikah

Not a stuck apex seal, engine turns over fine. Even kinda ran earlier today.

JOE68

fuel pressure ... adjust float
... i guess the search button goin to be your best friend ... good luck

Ta-Aikah

Done just about everything I can think of on the forum. Thanks anyways

racerx01

Do you have a FPR and gauge hooked up. Expect someone is going to ask about fuel pressure.

Ta-Aikah

Yep. Aftermarket Carter fuel pump that I've seen several people using successfully, and a FPR with a gauge in the engine bay, normally reads about 3-4 psi. Fuel pressure isn't an issue

Mivroum

What jetting do you have in at the moment?
How many turns out of the idle screws have you at the moment?

Ta-Aikah

65f9s for Idle, and About a turn out from seated on the mixture screws.

Mivroum

I have the same carb and the same idle jets.
I am waiting on my order of jets to go back to tuning the carb at the end of the winter.

I am approx 1.5 turns out of seated on the mixture screws and the car runs fine once warm. It needs tuning, I am too rich everywhere, but it runs.
To start, open it of 2.5 turns and work your way down to find the sweet spot (I think it is called best idle tuning - google it the procedure is the same for all cars).
At the moment I have stock advance timing and vacuum advance is hooked up (otherwise it seems idle is difficult without advancing ignition timing - so I was told, I haven't tried without the vacuum advance yet).

To start, because it is cold, I have to pump the gas two times before cranking the motor. It takes a few tries to succeed, and once started, I barely touch the pedal (too much and it dies - too little and it dies).
Once warm my idle is OK.
The "choke" system (more an enrichment circuit) of the DCOE is not connected on mine, I haven't tried to see if it makes start up easier.

You may find that the 65f9 idle jet is too rich, I have ordered smaller ones to try.

And ohh, you really need a wideband to make life easier.

Ta-Aikah

I'm not sure what it is but it seems like my springs are bottoming out before my mixture screws are. I'll have to take another look at it.

JOE68

u didn't try everything or the car would be running ..... did u pull the leading plug and see if u hav spark

Ta-Aikah

I've done enough of the common stuff, at least. I've got spark at all 4 plugs.

It's the initial starting that I'm having trouble with. I'm thinking it's lack of fuel from the accelerator pump, but my plugs come out a little damp every time I pull them.

JOE68

definitely missing something................... The Rotary Shop
springtown, TX 76082
United States
ph: 817-732-5081
therotaryshop@yahoo.com

Ta-Aikah

It's very strange. I'll give these people a call though. Thank you

j_tso

iTrader: (2)

From the first post, can you clarify that you have got the car to idle and for how long?


Are you starting it like this:
If it's pretty cold out, I have to pump a few times and a little more as it's cranking, then try to hold it a little above 1000rpm for about a minute before it will idle on its own.

Ta-Aikah

That's the problem. That's how I've heard I should start it, but doing that doesn't get it to start.