joconnell

alright, i will try and be as specific as possible, but if you have any questions as well as answers *hint hint* i'll see what i can do to answer them.

2 months ago or so i bought an 85 rx7 with a 12a in it. it wasnt running and the guy didnt know why. it's my first rotary and thought it might be fun to learn at the same time. it seems pretty straight forward so far.

after a bit of messing around, changing really old gas and the like, using only the weekends as its hard to get together with my buddy during the week (its at his garage as i dont have access to one right now), we had no luck.

in the end, after all the fun, we ended up taking the carb apart and finding the jets all gunked up, some butterfly valves siezed and some other dirty little filters in the carb. so we cleaned it all up and to test the jets we just filled the bowls manually with the top of the carb off. it wouldnt start. we decided to try and pour some fuel directly into the carb, not much, just a small amount.

it started, and would run at 1.5k rpm (we had to hold it) until the bowls emptied and then it would cut out. so today we put the top back on the carb, hooked all the lines back up and tried to start it... no luck. however if we poured a small amount of fuel directly in, it starts. but pumping the petal a few times doesnt give the small effect... its been years since i;ve owned a carb vehicle and i believe we used to have to pump the gas to give it a shot of raw fuel and it would start. well, this rx7 doesnt seem to do that, or doesnt like it.

so.. it starts when we pour fuel in... and stays going as long as we sit in the car and hold the rpm at atleast 1500. and there it seems like its really hunting. runs better at 2k. but we cant keep the idle there.

so! i head to my trustly haynes manual and it says i should have an "idle adjusting screw" and a "mixture screw". by looking at the picture in the book, we have the idle mixture screw but not the idle adjusting screw? does that seem right? or are some of the carbs different on different 1rst gens?

anyways, in the end i guess the question for here is, why wont it idle? adjusting the mixture screw has nearly 0 effect on it as far as we can tell.

jdi_knght

The idle adjusting screw is near the linkage where the throttle cable and everything else are (you'll have to look at it from the drivers side), kinda hidden down there. If I remember right, it's kinda horizontal.

Now if for some reason it's *missing* the idle screw that could explain why you always need the throttle opened, although you should be able to hold the throttle to around 800rpm. Then again, a missing idle screw PLUS a vacuum leak could keep that from happening.

In any case, find the idle screw first to rule that out as one of the issues if nothing else.

jdjl1987

Never ever pump a carb if your starting it, especially a rotary. One pump, foot to the floor and keep it there until it starts. Think about it, if it hasn't sparked it still has the initial shot so pumping floods them.

Also: fuel filter, fuel filter, fuel filter. Especially with bad gas. A new pump might be good too, but only if you're still not getting the right pressure after swapping the filter. Number 1 reason why first gens get staved for fuel. Ask me (and the tow truck driver) how I know.

joconnell

got a new generic pump and filter as well.

thanks for the info about te pumping though. some habits die hard i guess.

lascelles

also pressure of an aftermarket pump are often to high for a 7
there are a ton of threads on that and i hate typing

trochoid

iTrader: (6)

With the carb that gunked up, the only solution is to remove it and rebuild it. From your description the entire fuel system needs cleaned out too. That includes the fuel tank, lines and a new fuel filter. Depending on how long the car has sat, it's probably best to drop the tank, flush and reseal it.

Be sure ti buy the rebuild kit that has the AL washers. AutoZone here carries the better rebuild kit.

Kentetsu

I pump the gas 4 or 5 times, then start her up.

Have you got any fuel in the float bowls?

joconnell

yeah there is fuel in the bowls and if you have someone looking down the carb you can see the fuel going into the intake. but it just isnt high flow enough until the vehicle actually starts... almost seems like the idle circut isnt working at all. since it doesnt get enough fuel on crank to actually start and *it doesnt get enough to stay going*

* this is entirely an assumption. for all i know its getting too much at idle, once started, and flooding.

Kentetsu

You might want to try seeking answers over at www.sterlingmetalworks.com\bymc

There is also a library's worth of documentation, writeups, and tutorials at www.sterlingmetalworks.com

Sterling is our resident Nikki expert...