new to RX7 desperate need of help
 

So i'll start out with what happened. Was driving down the road at about 70mph when i began to decelerate I heard a pop and the rpm's dropped and the engine started to sputter. Now the engine will turn over and run, but acceleration is horrible and wont go more that 40. THe engine wont run over 4000 rpm and the engine will die if the rpm goes below 1000. I have spark from the coils to the plugs but other than that I have no Idea...
Please HELP

the car is a 87 mazda rx-7 base non-turbo

Compression test. :(

sounds like a blown seal my friend. same thing happened to me in my tricked out sundance. compression test is right!

I took it to the dealer and they said it sounded like a fuel problem is there anyway i can test the compression myself? and should i should the fuel filter and regulator.

The same thing just happened to me today! Maybe not the same problem, as I haven't checked my spark plugs yet, but same description: it idles and runs fine until I try to go over parking-lot speeds, then it bucks, hesitates, and soon dies.

Question for you: When I start it up and let it idle, the voltmeter on the dash reads 13.8 as it should, but when I try to go somewhere and it dies, the voltmeter slowly falls almost down to 12. Does yours do the same thing?

Question for everyone else: Could it be the alternator? Any other ideas? (Dammit, it was smooth as hell this morning...)

BTW, mine's also a base '87 NA, and the ECU isn't throwing any codes.

Yup...

please do not think it is anything else but ]1 either a stuck apex seal, or 2] a blown apex seal. your car is running on one rotor so please get it rebuilt asap. If you go on thinking it is the alternator etc, you will only be spending money on useless attempts. You have got yourself a blown 13b. Its okay though.

I won't be able to access my car until tomorrow evening, and I won't have net access while I'm messing with it. What should I check next if the compression test goes fine?

Hope I'm not usurping the focus of this thread, and I'll start a new one if you want.

Unless you're willing to work harder with a normal compression tester. And I mean ump the car once, check, again, and again. Six times. And I'm not even going to get into the readings. You'd have to test an RX with known good compression first to see what good readings look like before testing yours (depending on model). And I'm not sure but some types of gauges just don't work.

Your best bet is the Mazda (dealer has them) rotary compression testor. You can find one yourself but unless you plan on checking your compression VERY often, it'd be cheaper just to let them test it themselves.

Not an independent shop!

You can do the compression test yourself if you have a decent tester.

Sounds like a blown apex seal to me. Now you get to tinker with the car!!

You can modify a basic piston-tester by removing a little "check valve" that's screwed onto the tip of the tester, with a small set of pliers. Removing this will allow the needle to move freely with the rotary pulses.

SEARCH for 'how to check compression' (or something like that) if you need specifics.

BTW, you don't want to see any numbers less that around 90psi. Chances are (original poster), you'll see normal numbers of around 90-100psi (higher milage numbers) in the front, and around 0-30psi in the rear. :( At least that's my prediction.

You have described all the symptoms of a blown engine, there is a compression "how-to" on our website

Wha????

Not sure what he meant, there are tons of threads on how to check the compression on a 13b using a regular compression tester. YES you have to modify it and learn how to read it. There are TOO many threads on the subject to re-type the info here. Banzai is a good source.