Well...timing is perfect so i dont know what could be going on ignition wise. Fuel delivery....i did the fuel pump test and im getting enough fuel to the carb for sure.

I know you keep saying that timing is perfect, but there are a lot of things that can go wrong and screw it up.

Was the idle at or below 800 when you set the timing?

When you checked the leading timing, are you positive it was the leading timing mark on the pulley that it was set to?

Are you positive that the pulley is in the correct position, so that your markings are correct?

If the timing light has an advance knob on it, was it set to zero at the time?


I don't know, but ever since you checked the jets and found them clear, I'm thinking this is ignition related....

the timing was checked at idle...which was about 770 rpm. the marks, I re colored with paint markers and checked the proper ones. I cant see the pulley being out of whack but i guess its possible.

One other thing to throw in the mix is that I do have a small (no noise due to it) exhaust leak by the manifold which from time to time I get a tiny bit of smoke when I turn the car off....or return to idle after going on the highway for example. terrible smell...something maybe like unburnt fuel burning off in the manifold right by the leak, and the fumes escape at the leak. ORRRR maybe its from a plugged up cat. Im not sure, but I dont think it helps my case any

Could it be a leak from your carb, that is dripping on the hot manifold? That could be, um, bad... :)

I don't recall now, but was this thing running fine, and then it wasn't? Or has it never run right since you got it?

Because I'm still wondering if your pulley is positioned wrong, in which case you might want to check the Archive for the thread on how to determine top dead center. If the car has never run right, then I would probably do that next.

Been telling ya... cat is clogged. Your exhaust leak is evidence. The increased backpressure blew the gasket. All that pressure and heat buildup can't be good for the motor, right?

I will say Lizard has a good point. Although, I had the exact same problem with mine and found out the secondary linkage was frozen and was stopping the primary from opening fully. The combination of the two created no power and it would not rev past 5000 RPM's. I thought the engine was blown but after rebuilding the carb and breaking loose the seconday butterflies, she went all the way to redline.

Another cause is having the leading and trailing coils mixed up. Meaning the wires are going to the wrong coils. Your car will idle this way but sure as hell won't run very well.

Damn well worth checking, that's for sure. :nod:

I will check to see if im leaking fuel onto the manifold....but i will have to replace that exhaust. Guess i wont be driving it for a bit

Well while i was out there i determoned that its oil getting onto the manifold causing what i see as an exhaust leak, but this may have been caused by the back pressure. Hooked the secondaries up...and i got to about 6700 rpm but it stumbled once i used the secondaries. Definitly a plugged passageway in the carb for the secondaries.

Im going to buy the RP (rx7.com) bonez converter system and replace my crusty old and plugged up cats

Well. After weeks and even months of speculation...I have the results. (gasoline WAS causing the smoke on the manifold...good call Kentetsu!)

Rebuilt/tuned carb. 1/2 bottle MMO (marvel mystery oil). Several cans of seafoam (although I think MMO did the trick). AND removal of emissions along with the addition of mechanical secondaries. O yeah, 2 fuel filters, both new

All of this has turned my very sluggish and will not rev over 5k RX7 into a new machine! Can easily hit 8k rpms now, and wow what throttle response. Thanks to all that helped, and to all that were rooting for me haha

I followed this thread daily hoping you'd reach your solution. Glad it worked out for you!

Now you have to bring it down to Atlanta for the Mitty! :)



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