RENMAN

My brand new "Project 82", carbureted, will (must) start with the choke all the way out just fine when cold and THEN in a couple of seconds start bogging or a lumpy idle.

It will not idle smoothly above 1200rpms with the choke on - almost like running on one rotor or extreme engine miss if had pistons.

Can not get the idle to even hit 2000 rpms by pulling choke out.

Any ideas?

Many thanks.

By the way the choke fully closes when pulled, and opens slightly at start as its supposed to.
Choke will not automatically pull in to half choke in the specified time (or any time). Choke does open automatically when engine warms.

Too much choke causes loud backfiring - driving on choke when idling well (1100rpms) sounds like automatic weapons fire on deceleration.

RX-7 Chris

iTrader: (19)

I would try looking for vacuum leaks to start.

Where in Colorado are you?

RENMAN

I'm in Durango now. My old '79 RX7 made the trip to Colo Springs for 5 years from everywhere in the country many, many times to see girlfriends in younger and stupider days.

JoeyMazda

Do you still have the whole vaccuum system on your car?

RENMAN

The ENTIRE vacuum system. I am contemplating its removal though.

RX-7 Chris

iTrader: (19)

I would start there. Try spraying carb cleaner around the carb while the car is running and see if it changes the way it runs.

RENMAN

Haven't been able to locate a vacuum leak w/carb spray as of yet, even tried smoking from the brake booster hose. Nothing. Maybe there's a better line to smoke from? I have't had a '7 since '92 (the '79). It never, EVER had a problem, was ALWAYS miraculously smooth and carefree for over 170,000 miles.

I just bought this '82 and it needs lots of neglect work. I started with removing the LARGE Colorado Mule Deer indentation! It is rougher on accel than I remember my '79 to be - not bad for a piston car - just not like I remember on my '7.

So far, complete tune up, fresh gas and starting to run a tank of Seafoam. Set idle and mixture. Set timing. Lots of convienence electrical repairs. New fuel filter.

I will need to replace EVERY bushing on the car though. Yes, every one.

Well, I digress, but any other ideas?

74RX4

iTrader: (10)

Check this hose.

https://www.rx7club.com/1st-generation-specific-1979-1985-18/hose-question-750125/

RENMAN

The hose appears fine - a bit soft and doesn't hold very tight on manifold = will replaces it tonight. Is this a hose that disappears w/rats nest removal?

RENMAN

I see, it does get eliminated.

Kentetsu

The first time I rebuilt my carb, I managed to screw up when I put the choke back in. After that, when using the choke, the car would start to choke out just like you describe. Unfortunately, I never did find the cause for this. Problem went away when I replaced the carb with a Sterling.

I would look into the choke assembly...

Also, I don't believe that the choke has an automatic half-way movement like you mentioned. Just the full shut off when it gets up to temp.

Good luck..



.

RENMAN

Maybe only the 79-80 model had that - my 79 did - and I'm mostly going by a 80 FSM. Maybe the 85 would be better?
Thanks, we'll see what happens.

74RX4

iTrader: (10)

Many manuals (including 85 FSM) can be found at these links.
http://www.wankel.net/~krwright/cars/rx7/manuals.html
http://foxed.ca/foxed/index.php?page=rx7manual