Losing boost between 4 & 5k

[rotaryheaven]

Hi everyone, Im having an issue with my fc at the minute, when I put my foot down Im losing boost around 5k and it won\'t rev above 6k, when this happens which is all the time there is whistling sound from the engine bay. Sometimes it stops doing it but not very often. A friend of mine put some oil in the car whilst I was fitting some coilovers to it and this is when the problem began due to him over filling it with oil. Any help with this would be great. Many thanks ben

[m1tch]

Might be an air leak? On a turbo II you should be able to hear the turbo, what oil are you using? If you over fill a rotary it isn\'t as bad as a piston engine as there isn\'t a crank to go into the oil lol

WHen was it last serviced? might be an idea to check the error codes that are on the ECU, also is it running stock boost? if its running higher boost on the OEM ECU then it might be hitting fuel cut.

[rotaryheaven]

Hi mitch, The oil I am using is pro long rotary formula from Mazda rotary parts. You\'ve put my mind at rest about the over filling issue, I didn\'t know if it would be worse for a rotary engine or not. I can hear the turbo whistle away but if I put my foot down about quarter throttle it seems to pull ok but if I put my foot all the way down I seem to lose boost pressure at around 5k and get a air leak sound. I\'ve just fitted a racing beat fcd and the boost is set at .8 bar, my standard boost gauge doesn\'t read the same since the over fill in oil as well, my boost controller says one thing and the standard gauge says another, bloody annoying me now.

[rotaryheaven]

Oh yeah, I serviced the car about a month ago

[m1tch]

Is the boost gauge a proper mechanical one or a electrical one? What chipped ECU did you go for?

[rotaryheaven]

It\'s an electrical one from the evc 5, I\'m still waiting for the ecu to turn up from japan, apparently it\'s mapped for fmic, exhaust and downpipe, induction kit. I\'ve also brought a hks PFC f con but I\'m also waiting on that.

[m1tch]

You will probably find the OEM ECU is bogging down the mapping at the top end as a fail safe as its not ment to boost that high on a OEM ECU, I would turn the boost down to stock until you get the new ECU.

[rotaryheaven]

Ever since the problem started I\'ve had the boost controller off to be on the safe side but that is interesting to know, somebody told me not to bother with ecu\'s from japan due to the fuel being at 100 ron, does anybody do chipping over here?

[1990_fc3s_t2]

Anyone tried these??

I got one free with a used t2 maf, not fitted yet.

http://cgi.ebay.co.uk/Mazda-RX-7-FC3S-1989-91-Turbo-Stage-1-Performance-Chip_W0QQitemZ280445446282QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item414bd9e88a

[TiddlesRX7]

Are you sure your BOV isn\'t passing? I mean at high boost levels. Or maybe a split in a pipe that opens up at higher boost levels. These cars are getting old now and the pipes perish over time.

[rotaryheaven]

it could be, is there anyway of checking this? It\'s a hks bov that I bought second hand on egay, but saying that I did put on a almost new baileys bov and still had the problem. Hopefully I\'ll be able to get down to my unit over the next week and shall start taking off the pipes and give them a good look over. Could it be the actuator?

[TiddlesRX7]

Hmm not sure about the actuator (im sure someone more on here will). I do know that the wastegate\'s can give you trouble (boost creep) when you start modding. Normally people port the wastegate slightly to help. Im not sure if that would be related to your problems though.
People do check for air leaks by spraying carb cleaner (or something similar) on suspect pipes. If you get a rise in rpm then you have a leak on the pipe you sprayed. Just be careful if you try this though for obvious reasons.

[rotaryheaven]

i have heard of people doing that with the wastegate, i\'ll try that on the pipes when i get some free time to work on it. i did change some vac pipes for some ebay silicone tube, there\'s a good chance it could be them.