Beater86

alright so my car wont start, tried unflooding, tried spraying ether down the intake, still no luck, sounds so ****** close it makes me mad,
so some guy told me that you can get mazda to do it, but i dont really wont to tow it over there, or buy a compression tester for a piston engine, from canadian tire, put it in certain spark plug spots, and see what the number is,
will this work for finding out if its fucked or not?

hondahater

iTrader: (2)

did you change spark plugs? Are your spark plugs fouled? Probably so. If you go to www.rotaryresurrection.com under the tech section and then compression test it will show you how to take compression readings with a conventional piston compression tester.

HAILERS

Save yourself a couple of bucks and only buy LEAD plugs. The Trails are not going to help on starting. Just some FYI.

Beater86

the trials? ones that are in right now?
well i checked the spark plugs, all of them where making spark when i turned it over... so i duno

hondahater

iTrader: (2)

you have 2 differant kinds of plugs in your car, leading and trailing. The leading, like hailers said, are the ones that really are required for startup. So get the two leading plugs and put them in. Then try again.

HAILERS

I was just commenting that IMHO the Trail sparkplugs, the two top plugs, do little if anything for starting a car.

If your happy with the spark, then fine, leave the plugs alone.

It sounds like a 86 that has some years on it and is a bit low on compression. It probably has all the oil washed from around the rotors by now and is making even lower compression.

It probably needs some oil injected into the rotors, one way or the other so you can make compression to start the engine.

There's several ways to do that. Someone, with a 86 took the LOWER of the three vacuum tubes off the front of the dynamic chamber. He got a spare piece of vacuum hose and put one end in a quart of really light oil, say 10W whatever oil. Then you hook the other end of the vacuum hose to that lower metal nipple on the dynamic chamber. Then spin the engine over. That should cause oil to be sucked out of the quart container and into the dynamic chamber and from there into the rotors.

I've never done that personally, but it should work. Either use some real light oil or some oil that has been heated up so it flows better.

I think I'd disable the fuel pump while doing the oil thing. PUll the EGI INJ fuse in the engine bay when doing that. When thru, reinstall the fuse and reconnect the lower vacuum hose and start as you *normally* would.

rotarydelight

i compression checked my 90 gxl with a snap on comperssion checker and got three even bouncess on 25 psi front and rear. does anybody know what this equals to on a rotary compression checker?

Sideways7

iTrader: (7)

Not good. They should be in the 90's for decent operation. Good is in the 100's, excellent is 120+ Much below 90 is generally rebuild time. The fact that they are even makes me think its reading low, though. Is your battery in good shape? Low voltage can cause slower cranking and lower numbers. Also, aren't you supposed to have the car floored when you do the compression check?

88rxn/a

iTrader: (6)

yeah.. it equals rebuild unfortunately... sorry

Beater86

but if i have a blown apex seal causing low compression already, this wont do **** right?

Sideways7

iTrader: (7)

Just get a piston compression tester, they are 20 bucks at most. Pull the EGI fuse, stick the tester in the lower spark plug hole, hold down the release button, have a friend floor it and crank it, and look at the pulses. Even= no blown seal, 1 strong, two weak=blown apex, 2 strong 1 weak = blown side. More detailed expanation here: http://rotaryresurrection.com/rotary...lder/comp.html
Also, it seems I might have been wrong on the 25 PSI jumps. Just do it without holding down the release button and see the max.

locketine

Your engine can still run and should be able to start with a blown seal. Now if ur missing multiple seals...

I wouldn't jump to conclusions untill you do a compression check though. There are so many things that can cause a car to malfunction that assuming the worse will get you nowhere. Get a 10 dollar compression gauge at autozone or whatever your equivalent is. Make sure it'll fit your spark plug holes though.

What rpm is ur starter spinning at btw? You might not have enough juice or ur starter could have gone bad and can't spin the engine fast enough to start the car.

Sideways7

iTrader: (7)

Also, just because you get spark doesn't mean its good enough to start the engine. I would personally replace at least the leadings, since theyre pretty cheap. Also, don't jump to conclusions if you get two weaks and a strong. I got 30-0-0 and thought I had blown apex seal. Once I got the engine apart it turns out they were just carbon locked in place. In my case it was most likely beyond anything I could do, but you might could fix it with ATF of something if its not too bad.

86J

So did it not start on wednesday morning when it was -30 ish out? if so you probably flooded it. buy new ones and then it will fire right up. ask me how i know. Tuesday night i didnt set the timer for the blockheater properly. lol

Beater86

im not sure..how do you check?

HAILERS

***but if i have a blown apex seal causing low compression already, this wont do **** right?**

It takes about fifteen to twenty minutes to pull the lower plugs out and put a finger over one hole at a time while cranking the engine. If the pulses feel about the same on one rotor as the other then most likely there is no blown seal. Add oil to the rotors and press on.

Or buy a DI-148U from this site http://www.dataq.com/gl/daqguide.html and a pressure transducer and do it on a PC. There's several threads on this forum that address doing that. Search.

https://www.rx7club.com/forum/search...archid=1627281

HAILERS

https://www.rx7club.com/forum/showth...aq+compression