RX7BlueVillain

I have an 86 GXL with a S5 block.... Its been running great, got 2000 miles on the engine(freshly rebuilt)...I was driving along one day and it lost ALL power all of suddon... Then driving it back home from where I was going, it lurched foward and then lost all power again, did this a few times, then it lost all power for good... I have a fuel cut switch installed, and I have to use it to get it to crank, and it take about 20 seconds or so.. It runs rough, and it wont rev at all, it take about 10 seconds to rev from 1000-6000...I've heard many causes: clogged cat, igniters( I have msd ignition), egr valve, bad vacuum leak( I have vacuum gauge installed, and the vacuum hasn't changed any from before this problem to now).....it revs basically smooth, just really slow and odd?.... I did the engine swap myself, and i've done alot to RX-7's and I know them well.. But any help to someone whos been through this problem before would be awesome.
thanks

niner

how does it idle?
when you say your vacuum readings have not changed, what are they exactly?

I check the ignitors by pulling plug wire off just a little while car is running. you might just want to check while cranking (put screwdriver in wire and hold near a ground)

first things I would look for would be intake leaks and clogged cats like you mentioned. those will change your vacuum readings though

have you checked the compression? how bout the spark plugs? did you do all the basics w/ the new engine like like set timing/change fuel filter/adjust tps?

theres dozens of things it could be, you just need to start digging into it and checking things out. its not easy to diagnose cars online. if your good enough to put the engine in, then you should be able to fix it, just need a good manual

report back when you have checked some more things and I'm sure you'll get some more help

good luck