can't get new RX7 engine running

graybeard

Member
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Mazda RX7 1990 conv
My son's RX7 engine block (2 sections) failed. I purchased a used engine that was in a running car with only 2K since rebuild. It is a matching engine - non turbo. I have the engine in the car and it spins over. There is spark and fuel. I need a little help. My son is a college freshman, coming home this weekend for Thanksgiving break. I would really like to have the car running.
I live in Richmond VA. Is there anyone that can help me out?

Thanks!
 
You've come to the right place! Unfortunatly I don't know anything about the RX-7 engine's but I'm sure someone can help you out. Free bump.
 
These cars tend to flood when you leave them sitting for a while. Try pulling the plugs and crankig it over a few times, put the plugs back and see if the car will start. I'm not sure how long the car had been sitting but that's what kept happening to a friend of mine.
 
kytuner said:
make sure the apex seals are good. check oil pressure so you dont cook them

Thanks for the suggestion - I will keep an eye on it. Right now it has great oil pressure when cranking. Forgot to put oil sensor in when I first tried to start engine and quicky pumped out all the oil. What a mess!
 
orng1 said:
These cars tend to flood when you leave them sitting for a while. Try pulling the plugs and crankig it over a few times, put the plugs back and see if the car will start. I'm not sure how long the car had been sitting but that's what kept happening to a friend of mine.

I had heard the same thing but the strange thing is the plugs are not wet. I took the gas lines off and there is lots of gas from the fuel pump and it has good pressure. It like it might not be injecting. Very strange.
 
spray some gas into the intake if it starts then you know you have injector problems...check the coils...also make sure the wires are to the correct plugs....leading and trailing plugs and dont forget the regular stuff like fuel filter
trying to throw things out there...its been a long time since Ive fiddled with the rotary...good luck

Jeremy
 
wow, am i the only FD owner on this forum? I cant believe this thread hasent been solved yet.

Fist things first... compression check. take out the leading spark plug out of your front rotor housing, and attach a compression checker (this can be purchased at any local auto store). When you read the gauge, it should read three different numbers for each face of the rotor. A healthy compression is about 80-90 PSI.

Next, pull your EGI Relay (looks like a big fuse in your engine bay) and have somebody crank over the engine, and read what the gauge says. Like I said, there should be three different numbers, and they should all read about 80-90 PSI. This will happen fast, so you must make sure you have an open compression checker and make sure you try to turn the car over for atleast 10 seconds.

If it reads (for instance) 85-80-85, then all of the APEX seals/Side Seals/Corner Seals are good in that housing, and you may move onto the rear housing.

Your car is not starting, so i doubt that you have a broken APEX seal. Usually if your car has a broken APEX seal it will still run. My guess would be a problem with ignition or injection.

Check your spark plugs, and make sure there are no carbon deposits on them. While they are out, turn the car over and smell inside (or near) the housing to see if you smell fuel. If you have both of those things (spark and ignition) then it could be an ECU problem. Sometimes (very rarely) a wire can come loose going to your ECU. If you have an aftermarket ECU, you can easily check if it is getting power. This is a minor problem that the FC's had.

If its any other type of problem, like ECU or timing, I would take it to a shop, because I cannot troubleshoot that for you without looking at the car.

Do the compression check, then get back to me and let me know your results.

:D
 
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