New owner with questions

[lanciachris]

Bought myself my first rx-7, an 86 n/a.



I did a bit of research before it and made sure I checked for oil leaks, rust, overheating etc which all came up clear. but I did make a mistake and missed the exhaust manifold mostly made of paste, and its a real pig to start when hot, although the engine appears sound (good oil pressure, clean oil, no smoke etc). This may be down to some electrical oddness - there is a manual switch for the fuel pump which sounds like trouble to me.

Anyway, it shall be making a trip to rx-motors to get the manifold replaced, the fuel pump business sorted and to make the fans blow cool and hot air.

Further questions -
Its popping and banging on the overrun at the moment. Obviously this is amplified by the exhaust being swiss cheese, but should it be happening at all? I thought the twin plugs would cause pretty complete combustion

Where are the main grounds under the bonnet to keep clean?

And my main concern, a very wooly question does this sound like a car with a few niggles needing sorting, or a car which has been messed about with and will be a permanent nightmare?

[PIPFC]

hi,
welcome to the club,
                            the main earth point are right at the front on the panel which the bonnet clips on if i remember correctly. theres probably 4-6 blocks (looks like scart leads bolted to the panel- sorry first thing that came to my head as to what they look like, haven\'t been under the bonnet of one for a while.

as long as the bodywork is clean and as rust free as you can get i reckon its worth putting the few bits right. from what you say it sounds good with just a few bits need putting right. see what rx-motors say about it when you go there tbh. it\'s good to see a second gen still on the road as they seem to slowly disappearing.

somebody will correct me if i\'m wrong, i\'m just letting you know what i know
sorry if i cant be of anymore with the problems on your car.

[lanciachris]

Cheers, ill have a look for those blocks:) I thought id seen the last of cleaning earth blocks when I bought a japanese car - as the username suggests ive mostly been into italian stuff

Fingers xed for no more hidden surprises!

[Brett]

Ok, not wishing to be a doom sayer here, but :-

How many miles has the car done?

Hard starting from warm/hot is (in my experience) usually down to poor compression (ie a worn engine).  You may be able to ease matters by adding a little 2 stroke mix into the fuel.   The fuel pup cut off switch will be there to aid starting from warm. (The injectors have a tendancy to leak for a few minutes after shut off when they are old, this kind of \'pre-floods\' the engine before you turn the key, combined with being worn makes it a pig to start.  From warm, turn the pump off and turn the engine over for 10-15seconds, then atempt to start it with the pump on and you should have success)

 I hope it is just an electrical gremlin, but I\'m afraid the most liekly problem is worn housings and seals.

 Anyway, welcome to MRC :wave

[lanciachris]

Hi,
  I\'m still a little stuck with the car.. havent managed to get it running again since I took it home after a jump start - I didnt give it time to charge on the run home. A jump pack I bought doesnt seem to be doign the trick either, but the connection on the terminals isnt great so im going to pop the battery out of the car to charge it and try again.

The cars done 124k miles. I knew that compression was a risk when I bought it, but I am still not convinced its bad - the engine develops good oil pressure, no leaks, oil is clean, service components recent etc e.g. it looks like its been looked after. When I bought the car I saw it start from cold and warm with no problem.

I\'m getting a little frustrated but mostly the problems ive had with it are self inflicted so i cant get too annoyed at the car yet

[Brett]

They usually do have good oil pressure etc, and its probably been well looked after.  I\'ve had two EGI\'s, one completely let go at 155k, the other had similar mileage to yours and was showing the same symptoms.... it was so low low on compression I could turn it over with one hand!  
 
 Get it charged, check the plugs are ok and follow the proceedure for unflooding it, with a bit of luck she will fire up again

[Martiny]

Its flooded.
Buy a new battery , then try turning it over for a few seconds with the fuel pump off, and the pedal full down.Then switch it on while cranking and let us know what happens.

[lanciachris]

Got home today fiddled with the battery connections some more (god knows why they make the clamps on booster packs sizes that would never fit a battery terminal), and in a huge cloud of overrich petrol fumes it fired up nicely.

It settled down to its normal self - no smoke or anything after a minute, and I took it out for a bit of a run (not too long with the exhaust manifold made of paste). It behaved perfectly, which was very encouraging.

Got it back home and shut it off, gave it a minute and tried to restart it - got it on the 2nd attempt, fuel pump off, turn over with foot down till it catches a bit, then flipped the pump on and it started and ran normally.

I hope this means the compression cant be that bad. I have a compression tester somewhere, but not sure how to use it as regards the leading / trailing plugs.

Do rotaries burn oil (ie blue smoke) with loss of compression or does it just mean that some of the mixture slips past the apex seals and into the next chamber, doesnt get burned and is expelled?

[Brett]

All rotaries burn oil, its injected into the housings
Might be worth you having a read through the following sections, should answer most of your questions :yes

http://www.mazdarotaryclub.com/forums/forumdisplay.php?f=116
http://www.mazdarotaryclub.com/forums/showthread.php?t=9140

Hope this helps

[lanciachris]

Hi again,
  yep I understand rotaries burn oil by design, read the stickies before purcashing the statements earlier just makes me wonder how you are supposed to spot lower compression in a rotary without actually performing a test with a meter?

I mean, the cars are known for electrical faults, so if you can have good clean oil, good pressure, no smoke, how are you supposed to know if its an engine problem or an electrical one?

[grinder]

to be honest there is no real way of telling - apart from the hot and cold test

its easy to check the compression with a normal tester

1 - remove EGI fuse ( turns off the ignition and fuel )
2 - remove the top plug on the rotor
3 - on the tester - there will be a rellease valve - hold this in so that it wont hold pressure
4 - get someone to crank the car and dont touch anything
5 - you should get 3 even bounces on the reader - make a note of what they are - 85 psi is low compression - anything above that is good
6 - if you get 2 nice bounces and then 1 at ZERO its probably a stuck seal

i had an egi with 117K on the clock - drunk oil like it was going out of fashion ( oil seal shot ) but it ran like a dream

i did have probs with flooding - so i used to clamp the fuel line with locking pliers and then start it

with your fuel pump off - i would just start the car and dont touch anything

i have a imobilser on mine that cuts the fuel - so when im stopping - i let the car tick over - remove the imobliser and just as the idle starts to fluctuate ( no fuel left to run ) - i shut her off

she starts first time when you next come to start it this way

Stu

[Martiny]

To help prevent flooding. When you finish a journey:

1)get revs up to 2k
2)Switch off and floor it at the same time.

This pumps air through and cleans off the petrol while the engine slows down to stop.

[lanciachris]

After a trip down to RX motors the car is now plus a new exhaust header and y-pipe (and less one air pump and a shedload of other junk!)

I\'ve just about got the hang of starting it now. Seems likely from the behaviour that it has the leaky injectors problem.

When stopping the car I now switch off the fuel pump then let it run till it stops. This seems to minimise the amount of fuel the injectors could leak through