Boost Cut & Fuel Cut

[Tom]

Okay I tried to do some reading, but I couldn't really figure out what I was looking for..

But okay, here is my little question/dillemma:

Recently I installed a Pod Filter and CAI type thingo that I bought from Swift5_8.. That night, I went on the F3 freeway.. Cruising along in 5th I just put my foot down at one point, the car started to take off, then BOOM fuel cut and it was like I hit a wall, the car just dropped then took off again..


Now, I'm pretty sure it was Fuel Cut as it was pretty dramatic..

Normally when I take off, sometimes it'll rev up, spool up, then the spool will stop.. It'll be like the car is bogging down, but the revs are still there.. I assume that is Boost Cut!


Fuel Cut happened to me again a couple of days later, this time third gear accelerating hard.. It's like the whole car cuts off, makes a clunk and then takes off again =/


What causes these problems? Do you reckon it is the intake thing?

This is what I bought:

 

[matchtheclown]

They are booth fuel cut mate.

I would say that with the CAI your boost is spiking a bit higher / harder so before you where just touching fuel cut and now your are spiking right past it.

You are running a MBC after all, time to turn it down a little bit more. Cold night denser air in winter causes this as well afaik.

 

[pu-11-me]

Its the same thing man, just different names lol

If you get a spike in boost (Over the cars ECU limits) it'll cut your fuel hence the boost/fuel cut expression

Put the standard box back on, that thing you put on there has probably broken your air/fuel ratio making your car more prone to cut.

Also, now the weather is getting colder, fuel cut will become more of an issue..... Anyone with a MBC should keep an eye on their boost spiking in winter (Happens easier/quicker with cold air). There is a full explanation, I just couldn't be bothered as its bedtime haha

 

[pu-11-me]

They are booth fuel cut mate.

I would say that with the CAI your boost is spiking a bit higher / harder so before you where just touching fuel cut and now your are spiking right past it.

You are running a MBC after all, time to turn it down a little bit more. Cold night denser air in winter causes this as well afaik.

You bastard lol, beat me to it.... With exactly the same explanation!

 

[frozen]

the boost stopping while the car revs is just the engine taking more of the boost than the turbos can make - only solution for that is bigger turbos boost usually drops off after 5500-6000rpm..

 

[matchtheclown]

Winding the boost down should save it hitting the fuel cut, even with the CAI. I have the ARC box after all... and I think my MBC is still doing something..... however I never removed the factory boost solenoid so my boost is all over the joint weeeeeeeeeeeeee!

You see what reading this forum to much can do for you Dawso?!! This is my first turbo car I had NFI 6 months ago.

 

[pu-11-me]

You see what reading this forum to much can do for you Dawso?!! This is my first turbo car I had NFI 6 months ago.

:bigsmile:

 

[Tom]

Haha I'm the same as you Hugh, I had 0 knowledge what-so-ever besides "Turbos go WHOOSH".. Now I have a tiny bit of knowledge, thanks for the explanation guys I'll try turning it down and see how we go, and if it keeps doing it I'll have to MOD MORE!

 

[matchtheclown]

Your only option is ether a full replacement or piggy back ecu.

 

[Guest]

Yes its definately more air.
Good thing is the turbos should come on a bit quicker and better accelerator response and better fuel economy if its dialed in correctly.
Like the guys said turn the boost down and you should still get the car performing as well with 1-2 psi less boost but with the beter air intake.
Our cars dont really like the pods so you really should waste no more time and go straight for a piggy back.
Dont forget that my map ecu should arrive in about 8-10 days and I will tune it all without the maf sensor.
$400US for a new map ecu as $700aus for a haltech that doesnt let you remove the maf is a bit pricey.
If Carsten stopped painting and polishing his internals then he would have a whol write up on the map ecu but I will have to be the first I guess.

 

[bradc]

I would put the stock setup back on and see how that goes at the same boost level. I would also get a dyno run of the two and see how things go.


What I think has happened is that the stupid pod has fvcked up the shape of the airflow entering the maf which in turn makes the maf think it is receiving more air which means you hit fuel cut. I'd guess you've lost a sizable bit of power in the process.

Pod filters are stupid on cars that have a MAF like ours that depend on the airflow going past a sensor on the MAF.

 

[Tom]

Hmm I guess I'll go back to stock intake tonight! Thanks guys!

 

[Tom]

Actually I wound it down 4 clicks this morning, and it seems to still be going pretty well

 

[Guest]

I would definitly change that air cleaner setup you are running. It is in no way compatible with the MAF sensor and will be screwing up the readings fo the MAF. If you must have a pod filter setup, get the proper oval shaped K&N unit which at least is compatible with the MAF sensor. But I highly recomend going back to stock airbox and if you want a CAI setup, plumb some piping into it instead

 

[Tom]

Yeah I think I'll go back to the original set up anyway.. Like, I bought it thinking it'd be a good little thing to have, but I guess it turned out not to be!

I don't know how the stock snorkels work though? Like where does it pull the air from? Isn't it blocked by the bonnet haha

 

[Kenneth]

Let me get this straight...

You installed a pod filter setup.
You started getting fuel cut
You wound down your boost
No more fuel cut

So to summarise, you are now running less boost, but think the car is going pretty well?

Actually I wound it down 4 clicks this morning, and it seems to still be going pretty well

 

[Kenneth]

If you look at the bonnet, you will see there is a nice pocket to direct the air into the snorkel.

It pull air from the top grill area, which is about as cold as you can get without the opportunity for more rubbish and hydro locking your engine.

Standard airbox setup is good for over 200KW at the wheels, there is no reason to discard it unless you are doing some serious mods which require MAF removal anyway.

Yeah I think I'll go back to the original set up anyway.. Like, I bought it thinking it'd be a good little thing to have, but I guess it turned out not to be!

I don't know how the stock snorkels work though? Like where does it pull the air from? Isn't it blocked by the bonnet haha

 

[Tom]

Thanks Kenneth

I've wound it down till I get time to remove it back to the original airbox, so it's running well at the moment just on lower boost!