I have a '89 Rx7 and after driving it for a couple of minutes the car starts chocking and misfiring. If I put it in neutral and turn the ignition off and on again it will 'reset' and drive good for a while and so on...

I've tried diagnostic testing but having no luck there also! The dash doesn't display an engine test indicator and am struggling to get the correct plug for LED test.

Any advice will be appreciated!! Or if anyone else have had the same problem I'm all ears, (eyes).

Armo

 

http://www.1300cc.com/howto/how2/codes.html

Check the intake from the AFM to be certain all the clamps are tight, especially down at the turbo and intercooler.

 

Cheers for the quick response.

Tried the diagnostic test with the jump wire - unfortunatley there is no Engine check indicator located on the dashboard (Fog light - in the same position)
the only thing that i found from other websites is the temp of the engine - would this make a difference to the test.??????

I have also tried a different Idle Air Controller - which again made no difference.

Going to test all connections and will let you know but any further help would be much appreciated.

Reg
Pete Armo

 

What all is done to the car? And don't boost until you get the problem figured out in case there is a lean condition.

 

Please could you explain the lean condition.
I had a mazda mechanic look at the car who told me it was the Idle Air Controller. this was then changed but made no difference.
Seems very strange how it seems to reset itself if you put the car into neutral and restart the engine.
i have tried the diagnostic test which was found through this site which told me to run a jump wire from an output connection to ground (earth) and count the flases on the Engine check indicator located on the dash - i have no engine check light - this is where the fog light indicator is.
Regards
Armo

 

Oh, so there literally isn't a check engine light in the car. That seems odd to me. I'm not really sure how else to check it. Maybe wait for one of the gurus to chime in.
A lean condition is where there isn't enough fuel for the amount of air in the engine. Its either caused by bad tuning, too small injectors, or a vacuum leak. The latter is possible with your car, though I'm not sure why it would reset when turned off. Does it immediately reset, or reset once the engine cools down?
Also, are there any mods on your car?

 

Nope cant seem to locate the check engine indicator - it is replaced with the fog indicator.
There has been no modifications to the vehicle.
my next test now will be the vacum leak and then the 2 small injectors.
i will be replacing all the pipes over the next couple of days and any help with tesing your response would be appreciated.

 

I'd wait for some other suggestions before replacing a bunch of stuff. I'm just putting ideas out there. Also, is the misfire/stumbling at idle or under load?

 

the misfire is always when underload.
cheers for the response thou.

ALL HELP IS APPRECIATED

 

should my pressure sensor have a live feed at any point ( engine off / Ignition / engine start)

 

maybe your car is going into limp mode, when my OMP was failing my car would go into limp mode after exactly 10 minutes of driving, key off back on and it would be fine for another 10 min....

symptoms of limp mode, would be anything more then like 1/8th throttle andd car car will start sputtering and missing and wont hardly go at all..( it basicly cuts fuel out)

 

that sounds like the same problem - any ideas. ??? did you get the problem solved - heres a little more info

the turbo seems to boost as soon as the car is started.
after a few seconds the boost stops completely. if you then turn off the engine and restart whilst driving it seems to go back to the 1 boost.????

it was my father that told me to check weather all sensors were getting power and i have found that the pressure sensor gets no live feed weather the engine has ignition, started or not.

Could this be the problem - i have also checked many of the vacuum pipes which all seem to be fine.

Tried an engine dignostic which is mentioned all across rx7 sites but not for my UK model, the vehicle has no engine check light so i am left to evey rx7 enthusiast - please help

 

I have a Jap import and it has no check light so made one up similar to S4 type but only one led .Locate 6 pin green diagnostic plug near to the single plug you earth and place the positive wire of the led to B/W(12v) wire of the 6 pin plug and the negative wire of the led to Y/B pin of plug .Earth out the single pin plug turn on the ignition and led will light for 3 sec then flash codes if any. Codes are the same as in the S5 FSM If you want to check it is working ok dissconnect the oxy sensor and check the code flashes oxy sensor code as per the FSM.To cancle cods dissconnect batt lead for 10 seconds and reconnect .If all codes are gone you will only get the initial 3 second steady light

 

is there any risk of me affecting the CPU if this doesnt work. ?????

 

Have used this on my car without any problems,and i check for codes on a monthly basis as it is so easy to do.Going by the wiring diagram there should be no risk of effecting the cpu if you hook it up the way i stated .If you do not have the wiring diagrams then the link below has them all

https://www.rx7club.com/showthread.p...iring+diagrams

 

here are the two plugs i have located which you say i will be able to get a diagnostic reading from
just wanted to make sure i have the correct 2

the large six pin plug only has 3 wires connected to this
1 x Black
1 x Yellow / Black
1 x Yellow

please could you let me know if you think this is correct

reg
Pete

 

Yes you have the right plugs.The plug has only 3 wires ,are you sure that the Black is not a black white Look at the wiring diagrams that i mentioned in my last post ,look under turbo engine heading and you will see that the diagnostic plug has colour coding as i derscribed

 

You da Man

Managed to get the codes all we need to do now is to figure out what exactly is wrong
Here are the codes incase youve had any of the same
5 - 13 - 27 - 34

any help would be appreciated