I am considering buying a 1985 rx7 for $500usd. It is in great condition, interior and exterior. The engine has 120k miles on it, and has recently stopped running. The owner said that he was driving to work one day, it was very wet and raining(may or may nor have to do with the problem) and the engine lost power while driving and stopped running completely after a mile or two. Now the car will crank, the engine turns, but it wont start up and run. If you have any idea what may be wrong with the car and if the problem is the engine, should i try to fix the one in there, or get one in good condition from a junkyard? Thanks in advance.

Matt

 

sounds like a good find, might be something here to help,http://mrmazda.members.atlantic.net/...t.html#NOSTART

 

sound slike th engine is gone but that is just a geuss. do a compression check to find out. If the car is in very good to good shape I would pay $500 for one with a bad/questionable motor.

 

Yaya is right, start with a compression test. See what all six readings are and go from there.
Post if you need advice on how to do a compression test.
hanman

 

how do you do a compression test? what special tools are needed?

 

Do a search in here for the compression test - if its good, check the fuel pump, and then check for spark. If it doesnt have compression, I wouldn't pay $500 for it, but I'm a cheapskate.

 

Thanks for the info, I'm going to go check out the car on sunday. Really hoping it checks out good, I dont have the time right now to rebuild the engine or the $ to have it done. Also, are there any other things that could be the problem? I want to try to check out everything so I know what I need to get if I end up getting it. Thanks.

Matt

 

Someone on this forum, maybe rob from pinapple racing? said that lots of people come it saying that their motor just quit on them for no apparent reason and it usually turns out to be that their Oil Metering Pump (OMP) quit working. So he said that they pour a little 2 cycle oil into the carb or into the spark plug holes, and it fires right up. Pre-mix 2 cycle oil with the gasoline after that. 1-2 ounces per gallon to be safe.

 

Anybody else see something wrong with that?

 

In case you don't have a Mazda compression tester, and aren't familiar with compression testing with a conventional tester:

If you want a relatively accurate compression test you can use a conventional compression tester. Heres the process.
Disable the fuel system, pull the fusible link, plug the fuel lines whatever. You don't want fuel into the chambers when you are turning the engine over.

Pull all of the plug wires.
Pull the trailing (top) plugs from both rotors.
Screw in the compression tester in the top hole of the front rotor. Hold the release "pin" in on the tester, this will allow the pressure to immediately release on each compression "stroke".
Have someone hold the gas pedal to the floor and turn the car over while you watch the gauge. You should see the needle on the gauge start "bumping" up and down. After watching you can see the three compression cycles. They should all be fairly consistent and not too low.
Repeat the process with the rear rotor.
Also, the car needs a fully charged battery and good starter. It needs to rotate around 250 rpm to get a decent reading.
hanman

 

or since you're only spending a couple hudnred bucks on it, if you just want to see if the engine is "good" or "bad", yank the schroeder valve out of a regular compression tester, then look for three distinct pulses when you crank it over, if one or two (or all three) are missing on either rotor, then you're got problems probably. I forget what it should read when its good though.

 

a couple hundred is all i have right now. first, i'm only 16, and between school, soccer, work, and finding time to get some i dont have enough time to rebuild the engine or swap it. I'm goin out sunday to comp. check it. If its bad, then i dont buy, good comp, the car is mine.

 

ok, the car has 120k miles on it. if i end up buying anyway, is it a better idea to rebiuld the engine if its bad, or get one from a junkyard?

 

well, after finding out earlier that he already had 3 other offers for the car, highest being 450(he was asking 500) i decided to just go and hand him the $500 cash. I'll be towing the car home early tomorrow morning behind my moms car. I doubt there would have been that many offers for it if the other buyers had thought the apex seal was blown.

 

Good luck, and let us know what is going on.

 

would be great if it were only a fuel starvation problem, like clogged fuel filter, or no juice to the fuel pump, i had both of these problems and ended up replacing a rusted fuel tank too, but it works now, does gas pump thru the large fuel line if u pull it from the carb? good luck,,,will be fun to tinker with,,,,,,

 

hmmm, might have found the problem already Just got the car towed home. First thing we decided to check was ignition. We pulled the plugs one at a time and checked for spark. We only have spark on the bottom plugs(leading?). The top have no spark at all. The cables are new and so are the pulgs. The compression seems to be good, we didnt get a comp. tester, but when we cranked with a plug removed there were big puffs of air coming out and you could easily hear them.

 

It should still run without the trailing plugs. But it will run better with all of them working. Check the trailing ignitor and the trailing coil.
good luck,
hanman

 

yea, it just ran on 2 plugs. i replaced the trailing coil, nothing. is the trailing ignitor the only other thing that could really be wrong? and how much is it to get a new one?

 

It's not the only thing, but I would rule it out before I started looking elsewhere. Go to mazspeed.com and do a search for ignitors. There was a thread on how to test the ignitor very easily. That is if you can't find a cheap one to test it with. You can try ebay, I bought two spares on ebay for around $18 a piece.
hanman

 

cool, i ran the test on them, they checked out ok. Then i checked the fuses, one was falling halfway out, pushed it all the way in. Took out plugs, checked for spark, and i had spark on all 4 put the plugs back in, and it still doesnt run The battery is low, so i'm going to try jump-starting it later. I'll post if it works or not.

 

does it have fuel??? That would be the next problem i would check LATERZ, Andrew