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Title: Won\'t boost
Post by: RX7 R2 on February 16, 2007, 10:18:51 PM

Any one had this?

Replaced my NGK plugs rated 10 with 9\'s. Run fine on the drive. Took it a spin and as soon as I got the throttle pedal half open it lost power(didn\'t cut out) and tried to throw me through the window. :eek:

A short drive later and it has no problem revving right round the clock as long as you don\'t open the throttle too much. It appears that as soon as the turbo\'s try to boost it does the above, throws me into the window.

I thought it could be the vaccum pipes. I\'ve had a poke around the engine bay and checked all pipes but don\'t really know which is which.

Can anyone help me out?:xconfused

Title: Won\'t boost
Post by: Carl on February 16, 2007, 10:40:26 PM

It sounds like boost cut due to over boosting.
Do you have a boost guage on the car?What level of mods are there?
If you are on stock twins with a stock ecu and have an open exhaust you can hit boost cut.
Regards
Carl

Title: Won\'t boost
Post by: RX7 R2 on February 16, 2007, 10:44:07 PM

Carl

Yeh I\'ve gotta boost guage, no light though so didn\'t notice what it was doing.

The car is standard appart from a Blitz NUR cat back so yeh it\'s still running stock twins/ECU.

So what causes this?

Title: Won\'t boost
Post by: strange_days_uk on February 16, 2007, 10:48:27 PM

Boost cut kicks in at a set boost level. This is factory standard I guess the logic is to preserve the engine\'s life.

Title: Won\'t boost
Post by: RX7 R2 on February 16, 2007, 10:51:52 PM

It drove fine before I changed the plugs. Is there any main cause why it would of stared boost cut?
Also how can I stop it?

Title: Won\'t boost
Post by: strange_days_uk on February 16, 2007, 11:05:34 PM

It also could be loose pipe on the MAP sensor, or something similar.

Boost cut is porgrammed into the ecu. 2 ways to cancel it out:

Cheap: Fuel cut defencer, need to be careful of which type you get though

Proper: Remappable ecu like the Apexi PFC.

Title: Won\'t boost
Post by: RX7 R2 on February 16, 2007, 11:15:27 PM

I\'ll check the sensor. Daft question time, can you point me in the right direction, where would I find it and how would I ID it?

I don\'t like the sound of the fuel cut defencer. Sounds like it could end up in problems in the long run. Knowing my luck I\'d blow the engine. I don\'t mind the PFC and commander route, gives me a good excuse to buy one.:Thumbsup!

Title: Won\'t boost
Post by: strange_days_uk on February 16, 2007, 11:58:32 PM

(http://i32.photobucket.com/albums/d8/strange_days_uk/map.jpg)

boxed in red

Title: Won\'t boost
Post by: RX7 R2 on February 17, 2007, 12:09:30 AM

Cheers for the pic.
Just been and had a good mess and tough around the MAP sensor, well best I can in the dark but no joy at the min.

Title: Won\'t boost
Post by: RX7 R2 on February 17, 2007, 04:49:48 PM

OK I\'ve re checked the MAP sensor in the light but still no change. Anyone any other ideas they could throw down?

Title: Won\'t boost
Post by: RX7 R2 on February 17, 2007, 05:02:06 PM

Seconds after posting this I had a thought, reset the ECU which has cured it.

Mazda Rotary Club

General => General Technical => Topic started by: RX7 R2 on February 16, 2007, 10:18:51 PM