13bt sputtering

[translucentdj]

Hi all this is my first post on mazda rotary!!

Anyhoo i just bought a series 4 rx7 convertable and the engine is running a lil bit crap. full throtle in first gear is fine all the way through the revs but change to second, third and that it sputters after 4 grand, as this is my first rotary my know how is vaige, so ive changed the spark plugs that helped a tiny bit but i dont think that was the problem so ive come to the conlusion that either the airflow meter is on the way out, a pipe or valve is not on properly or the injectors are not running properly other than that im hoping someone can shed some light on it. Cheers.

[sadgoth]

Hello and welcome to another FC owner!

odd symtoms those, could well be a fueling issue, does it smell as if it\'s running rich? The fact that 1st is ok may also mean that it is an ecu or sensor problem?

[Prof]

could be the ECU

I know the series 5 has a switch to sense when you have 1st selected, and if you start the car in 1st it can defeat the AWS nonsense (mad revving when you first start the car).

Could be that this switch is also used to limit full boost and fueling in 1st, and allow it in the higher gears - you should look on the technical threads to see how to check the ECU - there is a diagnostic trick that you can do which will tell you about most of the sensors and output devices that control the engine.

You can find a link to your manuals here :  

http://www.rx7city.com/88manual.htm

Basically, you need to locate the green 1 way connector near the Front HT coils, there should also be a 6 way connector here.  With the engine warmed up, shut it off, then ground the single connector.  You will find that one of the connectors on the 6 way block will have a code being flashed out (From memory I think it\'s one of the middle ones).  To see the code, you need  to connect and LED and resistor between this pin and battery positive.  If there is more than 1 fault reported, they come out in numerical order.

Details can be found in section 4 of the manual - just choose from 4a /4b depending on if you have a turbo or not.

Hope this is helpful.

BTW - I am in the process of building a little gadget to do this job, and display the failures (in full text) on an LCD. If there is enough interest I might make up some kits.

[translucentdj]

hi all, ive got a mate that has a 13bt and fixed the problem in 2 seconds. he pulled out a plug to do with the boost cut and now it runs like a dream!! my previous ride was a r32 skyline and had more work than this standard rotary and the rotary goes harder!!!

Scott

[Compressor]

Hi translucentdj,
If the plug is from the little black box on the drivers side wheelarch you will need to plug it back in as the ECU cont read the correct boost and you will run too lean on the fuel.

You will need to get a fuel cut defender or some way of lowering your boost to about 7-8 psi max, That is if the car is still standard!!!