BobfisH

guys,

Did a bit of work on the car just now. Had a problem with hunting idle and stalling with AC on. Did a compression test at the same time.

Engine is a fresh rebuild with 3k. Front rotor about 103psi cumulative, with uniform bounces to 90psi. Rear rotor 118psi cumulative with uniform bounces to 105psi.

The difference is nothing to worry about, right?

Also, i had a bad idle; hunting and stalling with AC on. i jumped the TEN and GND connectors on the diagnosis connector to disable the ISC, and set the idle with the screw under the TB. Its a standard flat head that sits inbetween thetwo bolts that hold the elbow on. Remove the elbow - youll find it.

So yeah, i disconected my throttle cable, and set the idle to 750rpm with the TEN and GND bridged. I then noticed that my dashpot wasnt doing anything at all, so i adjusted it and it now engages about 2800 rpm.

I removed the bridge on the diagnosis connector, and the idle stayed the same? i read its supposed to jump up to 850? In any case, with the connector bridged and ac on the car stalled after adjustment, with the connector not bridged and ac on car no longer stalls so obv ISC is doing something.

I increased the idle slightly to about 850rpm (on stock gauge) as at 750 it was a little bit lumpy.

So i now have a car that idles about a steady 850-900 RPM, and after stabbing the throttle it returns to idle nice and slowly and smootly.

All thanks to FD3s.net!!

dubulup

I don't think cumulative psi means anything for a rotary?!?! Can't remember what I've read.

but sounds like your build is a success!! Great Job!

BobfisH

cumulative as in with a schrader valve installed in the comp tester. I copied the methology shown in Bruce Turrentines rebuild vid.

Mazda99Nikon

Interesting discovery. This is one that will be worth filing away.

Just out of curiosity, what are your vacuum readings?

1. Before the adjustment with AC off?

2. After the adjustment with AC off?

3. After the adjustment with AC on?

Thanks for the effort.

BobfisH

not sure o n the vac readings, problem is stilll occuring though - i think i just masked the issue to be honest.

How very strange. Think next on the book is hot wax rod replacement. My fast idle cam also doesnt seem to do anything at all - can anyone pinpoitn the cause of this as im not sure how the thing works? it doesnt seem to adjust anything throttle related externally so does it move something internally?