Engine cuts at 5000rpm

[rexgav]

Hi all i have recently bought my fd3s so new to them, everything seams to be running fine tickover etc apart from when i floor it it cuts out at around 5000rpm i then have to drop a gear and it goes fine again! i cant workout if it is fuel starvation or what, ive changed the fuel filter but made no difference, any ideas will be appreciated?

[neil_jdmr]

It sounds like fuel cut mate,
 
What mods are on the car?, is it a standard ecu,
 
Get a boost gauge if you havent already and find out how much it is running.

[rexgav]

Thanks for the reply, It is standard at the moment no mods at all just been out in it again and yeah it does feel like fuel cut but the problem must be after the filter as ive just changed that. Yeah i think a boost guage is the first things on my list to get as i don`t know what boost im running at all

[m1tch]

It might perhaps be the 2nd turbo not operating properly, which could be a boost solinoid issue which is quite common on an FD.

[rexgav]

So is the boost solinoid easy to sort out? Is it a replacement job or repair?

[neil_jdmr]

There are quite a few of the solenoid\'s in the rats nest mate, and anyone could be getting a bit lazy or even have packed up altogether and to test them means rigging up an air pressure source diy style or buying a mittyvac type instrument.
 
Before that though check all the hoses as they sometimes pop off or snap the nipples off the solenoid.
 
But before all that find out your boost pattern, it should be (in psi) 10 - 8 - 10 or (in bar) 0.7 - 0.5 - 0.7.
 
with 10psi being the first turbo, then 8psi is the 4500rpm switchover, then back to 10psi on the second stage till redline.
 
Before anything you need a guage mate

[JayDee]

It must be boost cut, from running to high boost on a standard ecu a boost problem ie bad solenoid, the car would not cut abruptly, does it rev past 5k with half throttle?
J

Hi all i have recently bought my fd3s so new to them, everything seams to be running fine tickover etc apart from when i floor it it cuts out at around 5000rpm i then have to drop a gear and it goes fine again! i cant workout if it is fuel starvation or what, ive changed the fuel filter but made no difference, any ideas will be appreciated?

[rexgav]

Hi J yeah it lets me go past 5000 at half throttle but then theres no boost

[JayDee]

Get a boost gauge on it to monitor the boost on full throttle, one with peak hold would be good or have a passenger look while you drive!

Hi J yeah it lets me go past 5000 at half throttle but then theres no boost

[mikeyrx7]

My fd3s had the same problem which is very bad, as i was running more boost on a standard ecu i had a FCD fitted, been amazing since and gained 13 hp but that was with a de-cat and boost controller and most important upgraded fuel pump and 14v wiring....

[rexgav]

Just to update im still having the same problem, Ive since changed all of the solenoids including the complete rats nest and now fit a new boost gauge. Ive just took her out and its reading 20psi of vac then only 5psi of boost max! Is this showing that the turbos arn`t kicking in at all?

[smarts]

It\'ll probably be worth checking the hoses from the intercooler - mine had something similar and it turned out one of the hoses was split on the underside but it would only make itself known under higher revs. Its why some folks get hard pipes to replace them.

Simon

[neil_jdmr]

Check the two plugs on the front of the uim are the correct way round other than that my 2p is on split ic hose as mentioned above and most likely the y pipe connector

[Jono FD3]

When my IC pipe went, it split about 2 inched in length! Bin the stock mazda flexi rubber things & get eather a silicone IC kit or a hard pipe kit!

Mikey RX7:
You are in danger of running lean with the mods you have!! Fuel cut is there to protect the engine, if you disable this & turn the boost up on a stock ecu you are going to create problems even if you have 14v & a bigger pump..... The fuel pressure will still be the same in the injector rail unles you are running an aftermarket pressure reg?? but even then you still need a remap on an after market ECU!

Jono