Evo 5 fuel/boost cut problem

[z0ton]

I'm just posting on behalf of a mates car that we've been working on. We didn't think it was going as well as it should be so we installed a boost gauge to find that it was only boosting a maximum of 12-13psi.

So we installed a manual boost controller to bypass the factory boost control solenoid which we thought was probably stuffed.

We can now adjust the boost higher but whenever boost hits 15psi the car will cut out just like a fuel cut which we're pretty sure its doing. We have set boost at about 13 - 14psi and it's running fine in full throttle all gears.

Any ideas what could be causing it to cut out whenever it hits 15psi? Factory boost cut is meant to be from 18psi or above, same say more like 21psi.

DETAILS: Evo 5, turbo back 3" exhaust, K&N pod filter, Racepro Blaster external BOV(already on car, not my choice lol) and GFB manual boost controller.

[tsoob]

I'm just posting on behalf of a mates car that we've been working on. We didn't think it was going as well as it should be so we installed a boost gauge to find that it was only boosting a maximum of 12-13psi.

So we installed a manual boost controller to bypass the factory boost control solenoid which we thought was probably stuffed.

We can now adjust the boost higher but whenever boost hits 15psi the car will cut out just like a fuel cut which we're pretty sure its doing. We have set boost at about 13 - 14psi and it's running fine in full throttle all gears.

Any ideas what could be causing it to cut out whenever it hits 15psi? Factory boost cut is meant to be from 18psi or above, same say more like 21psi.

DETAILS: Evo 5, turbo back 3" exhaust, K&N pod filter, Racepro Blaster external BOV(already on car, not my choice lol) and GFB manual boost controller.

u sure the gauge is right?. fuel cut? speed cut? the gfb ones are pretty good in my experience, are these AFM or MAP engines? does it jerk or cough and splutter?

[MR2BOY23]

You sure its not ignition cutting out? could be your plugs burning out

[Caribeena]

airflow cut off... how big is the intake? Factory ECU? Had it happen on my evo turns out it was drawing in way too much air for the computer to know what to do with

[Loudtoy]

Evo 5's are a hot wire afm arent they?? IF so then the above message is probably very true. Is it running the standard airbox/panel filter or aftermarket. Afaik when the hot wire in the afm gets to cold the resistance is to much at one end of the scale and the computer throws a wobbly as it's outside the limits built into it.

[Titties]

PM sent

[Rych]

u sure the gauge is right?. fuel cut? speed cut? the gfb ones are pretty good in my experience, are these AFM or MAP engines? does it jerk or cough and splutter?

It pretty much feels like a speed cut, complete loss of power.

airflow cut off... how big is the intake? Factory ECU? Had it happen on my evo turns out it was drawing in way too much air for the computer to know what to do with

It's a factory intake with a K&N pod, all the rest of the intercooler piping is factory. Factory ECU. I had it checked over today by my mechanic with no luck although he didn't do a proper leak test. I've got it booked into Mag n Turbo this friday to get a intercooler / vacuum line test done.

Otherwise I might have to start looking at the ECU and get a tune or raise the boost cut.

PM sent

I'd be quite interested in that if I can't find any other problems. Although I'm pretty sure boost / fuel cut doesn't normally come in to around 19psi. Factory it should be running about 14-16psi.

[Rych]

Cheers Titties for your help!

For others information, hooked the ECU up to a computer and found the factory air flow set at 200% along with the extra flow of the exhaust and intake which was causing it to cut at fairly low boost. Upped the air flow to 230% which should allow up to around 20-21psi boost. Got it on 16psi till I get it tuned / check fuel and knock etc to make sure its safe for the high boost!

Speed cut raised to 260km/h too.