Hey guys. I finally own an RX7. I had one years ago but due to circumstances it went away. So I finally have another. It's an 88 convertible white with 274k miles.

First off - anyone who wants to say bad things or "shouldnt have bought it" things or anything like that - go away. I'm excited and I'm not some dumb buyer who picks one up. I have been looking for months. and this one came along and it was an old ladies who didnt need it anymore and asked $1200 and i paid $800 so I win.

Everything works inside, top works no leaks all that stuff and mechanically for the most part it works great. but i have a few questions about some quirks.

disclaimer - it needs a new alternator (i think), a new starter for sure and who knows how old the fuel filter is.

I am VERY fluent with RX7's.

First - the compression - I have no way to test it and due to my location (150 miles from a large city) I dont know when i will make it that way. that being said, there is nothing with how it runs. the motor is smooth and revs fine and pulls the same all the way up the rev range. Also, it starts up warm or cold fine - at least when the starter catches - and doesnt exhibit any other odd behaviors. Am I safe to assume the compression is okay? I assumed I would notice a flat spot in acceleration or the start up would be difficult and in fact it starts fine, and idles warm perfectly.

second - the idle when cold is a little haggard. nothing terrible, but I'm OCD and i notice the occasional blip in the smooth idle. not sure what that is. Also, it idles a little low sometimes. i have narrowed it down to the alternator i think becasue it drops when i press the brakes, go in reverse (lights up the backup lights) or have the head lights on. I think it's the altrernator dragging it down and therefore causing the low idle sometimes.

LAst, something I have noticed - sometimes on startup... only done it twice so far - but will die after it starts up and goes up to 3000 rpms. I think rx7's have a cold start sensor or system I'm not aware of. Also, along the same lines, I revved it up to show a friend, only to about 6k and when i let go of the gas it dropped to 500 then died. I'm also thinkin fuel filter becasue if its blocked up good, then it will choke the engine.

Just some thoughts Im putting out there for you guys since in my area there is no rx7 club or anything.

 

rx7s are ment to go up to 2000 when it goes to 3000 tap gas and i will drop back to 2000 the do this to warm up

it probably needs a rebuild, it can start fine pull the same through the power band but that doesnt mean it has good compression just so you know. 274k it a ton of miles for the engine mine blew a 157k and i thought it lasted a while. if it has a rough idle it could be vaume leek or low compression. just be prepared to rebuild it soon
but 800 is not bad for a vert
oh and warmed up it should idle at 750

 

it idles at 750 fine, but once i do anything that puts a draw on electrical, the RPM's drop some. (headlights, fans, reverse lights)

I'm trying to find out if it's been rebuilt once before. i agree that 274 is a TON of miles and i would be amazed if it made it this far without a rebuild already

 

when the rpms drop some, thats just your alternator kicking in
do a compression test either way jsut so you know.
that would be a world record lol 274k, the highest i have seen was 230k.

 

okay. i will try and find a way to do a compression test, but im not sure how considering where i live. once i do that and if it comes back okay - what then?

 

if the numbers are good then youhave a good engine, if they are bad then it needs a rebuild
i thought you owned the car, why is it so far away

 

sorry. what i meant was, yeah i own it and its here in my driveway and i LOVE driving it. i meant to say that any rotary club is far far away from here. i think i have the only rx7 in the Valley. So, im unsure what kind of tool I need to buy at the car parts store for a compression test. a regular one? anything special about it i need to do?

 

get a regular compression guage and hold the air bleed off it should bounce evenly 3 times on each rotor. then let off the bleed off valve and do test again and hopfully its more than 100's you have a very good engine, if its 90's start saving for rebuild, if its 80's and below it can blow at any time
one of my engines had 80 and ran good for 3 more months just depnds on when it wants to quit
and here is a site with a ton of help full information
http://rx7city.com/techconnect.htm
just scroll down a little and you will see all the links and are year and genration spcific

 

will do. i was thinking about it and thought maybe the fuel filter/fuel pump might be it. but i guess there is no point in doing anything until i check the compression eh?

 

you can also bypass the cold start by starting the car in first gear (if its a manuel trans)

 

okay i will see what that does to the idle. Im just not convinced a seal is bad but i will check tomorrow. it drove great the 150 miles from the city where i bought it to my house.

 

i not saying your engine is bad just sayig when you gat a used car you should know what conditon your engine is in

when your idle goes up to 2000 it helps it warm up faster
talking about yur fuel filter it wouldnt hurt to do full tune up. new spark plugs, spark plug wires, oil, oil filter, fuel flter, air filter, changeing your gear oil in or trasmision and your rear end, and your coolant

 

no worries and i agree. but for $800 i couldnt resist.


so i will get a compression tester tomorrow - what steps do i take to check it right?

 

i would have bought it to, i have always wanted a vert.

when you do the test, hold the air bleed off and make sure you have 3 even bounces to make sure all 3 apex seals are good, and the do it again but dont hold the valve to get your over all compession
do the samething on front and rear rotor, when doing the test make sure your take out your egi fuse, located by the driver side front strut and hold the throttle wide open.

 

okay. will do. say a pray for me tonight before bed hoping they are all good.

i will update this thread tomorrow with the results.

pray pray pray

 

i will
let us know how it turns out

 

did some reading last night and before the guy with the tester stops by, im gonna check the BAC valvue too.

 

nice

 

reason being - from everything I read, it said the BAC valve controls the engine speed when load is applied - more or less. so when i press brakes, reverse lights and what not, if the BAC value is bad, it wont adjust the engine speed accordingly as the load changes. for example, when im driving, then let out the clutch and press the brake, the engine load increases while the power output drops. so maybe i will get lucky and the BAC valve will be the culprit.

 

The alternator doesn't "kick in" on any car. The battery starts the car and it uses the voltage from the battery to run the electrical parts.

It would be a good idea to get the alternator tested and see what's going on.

 

will do. Thanks - anything other than an apex seal and I can sleep at night. LOL

 

HELL YES. compression is good. first time is spiked to 100 and next round it was 85 and last round was 85 to 100. kinda bouncy since we are rookies at it. LOL

so what next?

 

its not that it kicks in, but when it starts pulling more volts it puts more load on your engine that why your ile bounces it does the same thing if you have power steering and turn it to full lock


sounds like you have a good engine
100 is very good

 

so since i have a decent engine - what should i focus on with the idle?

274k with good compression - must be a replacement engine...

 

You do realize that the alternator is what makes power in the car, right?

If you're talking about lights and power steering pulling current from the alternator, it's possible but again, that would indicate a bad alternator.