abdul k

Hi guys, i am new here but i always followed your advice and thru your pass threads,
I have a 1996 mazda rx 7, the car was bought on a Japanese auction when it arrived in SA there was green water build up in the passenger side which i sorted out.
The car back fired alot and did not go pass 5000rpm.

I found the rubber hosing to have had holes in them which i replaced
I ground new earths
Change the alternator 3 times due to over charging
Changed the ecu with another 1996 ecu
(old ecu 0.3 boost)(new ecu 0.5 boost)

Now the car dont boost pass 0.5 but revs up free, there is no power and some times it goes without struggling but when it starts to back fire, as soon as i switch the car off and on it goes fine (still boosting to 0.5)
I am not sure if its a mechanical or electrical fault because the turbo and the seals are fine, the waste gate works , the precontrol works
What else could be wrong
Does it need a new wiring harness as the old ecu had residue build up due to the water leak

Please advise

misterstyx69

iTrader: (142)

have you compression tested the engine yet?

abdul k

It is building compression because i drove it for 1200km and it went find beside the hesistation now and again, i am not sure because of the water leak maybe there is some wiring thats gone bad, looks like it will need a whole wiring harness

Sgtblue

iTrader: (16)

What exactly do you mean it has no power? JDM cars don't have a Check Engine Light, but IIRC there's a way to pull codes. You might be in limp mode.
See if you can come up with a Factory Service Manual for your car.

abdul k

I took it for diagonistic when the car first came and the code that came up was the omp open short, i got the omp check and it is working fine, ran one more check and no codes what so ever.
Yesterday morning i was taking the rx7 for a drive and notice that it was not charging the volt meter kept showing low and the car switched off, after repairing the alternator 3 times, this time i got it replaced, the volt meter read between 13.8 and 14.1. My old man been a Supra rz owner ask to go for a drive in the rx7 and we went for a long drive (637km) and not once did the car hesitate despite not boosting pass 0.5 bar, it went awesome my old man drove it for 400km and could not get enough, he was enjoying the ride the bend handling at 165km, he said with a supra he will think twice but the rx7 he was just going for it.
He enjoyed the car so much that he stole it this morning and have not return home yet lol

Only two things are notice on the drive :
0.5 bar boost
When the i turn the stereo own the voltage drop to 12.2 and when i switch it off the voltage short up to 13.8 (Honestly the FD3S dont need a stereo because from 3000rpm it makes the best music ever, i think that same sound inspired beethoven lol)

So guys what can i do to get it boost to its normal 0.8bar
The car is stock besides the performance exhaust (stock cat still there) and it has a cone filter

Sgtblue

iTrader: (16)

Any of the three codes related to the OMP will put the car into limp mode. (no timing advance and fuel cut if vacuum isn't present at the intake manifold). When it backfired and wouldn't accelerate/'rev' you were probably in limp. It may come back.
-----> http://www.autosportracetech.com/RX-7/rx7stuff.htm

And I still recommend strongly you get a FSM.

abdul k

Fsm ? please can you explain what it is and what it does,

d0nald

An FSM is a Factory Service Manual. It will tell you the ins and outs of your car, from complete teardown to complete reassembly of pretty much everything in the car.

Sgtblue

iTrader: (16)

Downloadable versions available in the 3rd Gen. Stickys. Alot of other good information there too.....hint hint....

abdul k

Thanks a million bud, but just a quick question will you think an aftermarket ecu will help solve this

Sgtblue

iTrader: (16)

No, not your boost problem.

abdul k

Hi there its been a long time , i finally handed the car in to the only rotary specialist here in Durban , and he notice that the car is boosting only on the primary turbo and the secondary refuses to come in , i looked at the secondary turbo diagram and all that was said to check are fine so what else could be wrong

abdul k

Guys i got the car back and the problem was the second turbo housing had cracks on it so it was not building pressure, the mechanic threw in a new turbo system and he told me its better if the car is non seq, the boost pattern is 0.8 , holding at 0.7 then 0.8 again , last night i took it for s drive and in the third gear at 6000rpm the 180kmh limiter kicked in .
I read the past threads about cutting the wire on the ecu, my question is for a 96 fd is it the same green and red wire and will cutting this wire effect the cars handling or anything else

Please advise

Sgtblue

iTrader: (16)

Your mechanic suggested non-sequential because he was unable or too lazy to figure out the sequential system. While it's decidely simpler, it's not necessarily "better".
Did you see this "cracked housing"?

abdul k

Aha lol i do agree with you but he did a good job, yes i saw the cracked housing and if you look at it you will not notice a thing until you pass liquid or wind threw it then you will notice where the cracks are . Anyway will the 180kmh speedo limiter removal will it have any affect on the handling, please advise as i will like to do it tomorrow