My '88 engine blew with 95,000. I sent my engine to Atkins Rotary in Washington state with the "good" rotor #1 having avg 8.0 kgcm2. They rebuilt it & performed a stage 2 porting to improve horsepower. The engine left their shop with a bench test compression of avg 9.3 kgcm2. After re-installing the engine, the car wouldn't start. 2 different RX-7 techs in my area (considered to be the best rotary techs at their dealerships) could not get the car started. After researching further, I replaced the air flow meter and the car started. However, the tech still could not get the car started & stay running. Tested to be fine was the crank angle sensor. This tech tested the compression & it tested @ avg 6.3kgcm2.

Engine symptoms now: it cranks fast (normal) sometimes & slow other times. Starter tested good. It floods easily on start up preventing starting (I have to crimp a fuel supply line to get it started). Once running, the car seems very sluggish (low rmps - lower than my old engine without porting), stalls at low rpms without a/c on.

 

6.3 isn't so good. You know there's a thread exactly like this, just one below

 

Do you have the fuel pressure regulator hooked up to the correct vac nipple???

if you have to pinch the supply line.. its getting too much fuel..

you didn't revers the fuel hoses did you???? If your not sure, reverse the lines and try it..... guys have had similar problems with J=Spec engines because they hooked them up the american way and they are reversed on J-spec spiders.

A stuck injector can cause this as well, you didn't ground out an injector wire when you had the wiring harness off did you???

 

How many miles have you been able to put on the rebuild so far?

Also, it sounds as if your battery isn't up to par if your cranking is at all slow...

Did you see the results of the Atkins compression test? Or did they just tell you that...?

Another thing, if you guys (tech's) could get the car *started*, but couldn't keep it running, it sounds as if there are other issues at fault.

I'd suggest installing a fuel cut-off switch so that you don't have to 'pinch' a fuel-line or whatever to start the car. (fuel cut-off switch takes about 5 minutes to wire up, search). Put some miles on the rebuild, make sure everything else is installed correctly, get a good battery and then check the compression again at 500 miles or so. If you still haven't gotten good or significantly better compression, call Atkins and tell them you are unsatisfied with their motor and make them square up with you...

 

just a FYI
a freshly rebuilt motor wont make very good compression and will be difficult to start! it can take as long as 3000 miles before hte motor is broken in and the max compression is realized, before that it will have a lack of power, be difficult to start, and flood very easily.
how many miles are on this engine??

also make sure you dont have any vacume leaks! and the fuel lines the wrong way will cause funky problems

 

Thanks for the information. I will check/ double check the things you all mentioned. It gives me some hope that the lower compression readings are possible on new rebuilts- I'd sure hate to have to yank the motor back out. The motor only has only 56 miles on it due largely to the stalling and difficulty starting- I don't want to get stranded out on the road. I'll see how it goes and let you know.

 

If I were you, (unless you install a fuel cut-off switch ) you should simply park on hills, and only hills...

This is what I did for my 1st rebuilds--just 'compression' start it every time. It'll start whether or not it's flooded.

Unless of course you LIKE getting out of the car and pulling the EGI fuse, then getting back in and cranking, then getting back out and reinstalling the fuse, then getting BACK IN and trying to start it? (lol) You get my point.