Where is my fuelcut o_O

bMX · July 13, 2009, 10:00:02 AM

Hi everybody,

yesterday i passed the mark for 2000 miles after engine rebuild.
I drove the FC Turbo2 S5 with boost set to 5PSI with the BLITZ SBC icolor.
after the 2000\'st mark i set the boost to 7.2PSI and ... i think you know what I do :Laugh

However, the boost fired over to which it was set - it fired up to 17.5PSI !!!
I realized this after analyzing the power graph of the boostcontroller and did not have a fuelcut :eek - with stock engine and turbo @ ~17PSI

?? :confused:
It\'s terrifying!
Why did he fire up?

MANUAL
Set: 50 (this unit is set to hkPa (german: "bar") - about 5PSI)
Gain: 23
Limiter: 25

Setup: Booscontroller, HKS-SSQV, stock turbo (not ported), stock exhaust and downpipe, stock airfilter - everything stock!

Mods: removed BAC, ACV, air pump -> everything blocked off.

Well, i love big boost, but not with stock (non ported) turbo and stock "downpipe", stock ... everything

Maybe my setting is too much?

Round and round,
Ben

bMX · July 13, 2009, 09:36:55 PM

Pls. take a look @ this

http://www.youtube.com/watch?v=35zNQvUULIc

pdtaylor18 · July 13, 2009, 10:15:09 PM

What ECU are you running??

bMX · July 13, 2009, 10:27:36 PM

I Think it is the N380. But to be shure i have to take a look.
Either it is the N380 or N372.

pdtaylor18 · July 13, 2009, 11:03:09 PM

Just wanted to know if it was standard or not. With standard it should have cut fuel unless you have a seperate FCD in there, you certainly do not want to do that too often, impressive to get to 1.2 Bar though without the turbo showing signs of the strain.
So to be honest you may have a few probs,
Why did it not cut fuel
Why did it not control boost

Might be worth seeing whats fitted,if its got any sort of FCD that will be attached to the ECU or at the boost sensor itself. I dont know the blitz SBC but someones bound to give you some more pointers on here.

Prof · July 14, 2009, 07:34:39 AM

How are the pipes connected around the wastegate, solenoid and turbo ?

With stock air filter and exhaust the turbo should be restricted so much that it shouldn\'t hit boost like that.

bMX · July 14, 2009, 09:18:53 AM

Quote from: pdtaylor18;626014Why did it not cut fuel
Why did it not control boost

Exactly!

Quote from: Prof;626053With stock air filter and exhaust the turbo should be restricted so much that it shouldn\'t hit boost like that.

HKS-airfilter mat in stock airbox and stock exhaust (downpipe...). Ok, the exhaust is not sealed up to 100% but should not make any problems.

Pls. see the pictures below for the piping.

Prof · July 14, 2009, 11:24:38 AM

Ok,

So item 3 is the boost controller and reads the manifold pressure which you have taken from the manifold and also feeds the stock MAP sensor and blow off valve - no problem there.

Item 1 is presumably the boost control solenoid - and should have 3 ports. On the diagram you cannot tell which ports are connected, which port are you using for the wastegate actuator, and which port takes it\'s feed from the turbo compressor outlet ?

You might also consider the following test:

Disconnect the solenoid from the boost controller and connect the two hoses that go there together - the turbo should only be allowed to make spring boost (or just a little higher) so that should be about 5-6 psi.

You can then make the same test with the hoses connected but the electrical connector still unplugged - this should give the same result - if it doesn\'t then the solenoid valve is either faulty or the hoses are not connected correctly.

With boost controllers like these, the wastegate should be connected to the valves \'COM\' or \'Common\' connection, and the boost source (Turbo outlet) should be connected to \'NO\' or \'Normally Open\'.

Connecting it this way means that the turbo outlet should be connected to the wastegate when the solenoid has no power applied (failsafe).

bMX · July 14, 2009, 12:44:12 PM

Hy Prof,

thank for fast answer!

As I understand you correct you say to crosschange the hoses @ #1 - pressure sensor?

The upper pipe from the turbo is the right one in the picture and drawing (see manual, this is OUT) , the wastegate pipe is the left one in the picture and drawing (see manual, this is IN).

DAMN!!!!!!!! See u later :2eek:2eek:2eek

EDIT:
But this alo the reasen for no fuelcut? That\'s what I cannot belive.

Prof · July 14, 2009, 01:17:56 PM

Quote from: bMX;626138Hy Prof,

thank for fast answer!

As I understand you correct you say to crosschange the hoses @ #1 - pressure sensor?

The upper pipe from the turbo is the right one in the picture and drawing (see manual, this is OUT) , the wastegate pipe is the left one in the picture and drawing (see manual, this is IN).

DAMN!!!!!!!! See u later :2eek:2eek:2eek

EDIT:
But this alo the reasen for no fuelcut? That\'s what I cannot belive.

I think your fuel cut is another issue, it might be you have a chipped ECU - the only way to tell for sure it to lift the lid and have a look at the chip. The stock Mazda ones all seem to have a black label with silver/white letters and numbers on the EPROM chip.

See pic here for location of chip:

http://www.mazdarotaryclub.com/forums/attachment.php?attachmentid=23944&d=1159912639

bMX · July 14, 2009, 01:20:52 PM

Ok, just changed the hoses from #1 - pressure sensor (solenoid).

Driving home after work will tell me if this could solve my issue :WaveBye

Prof, thank you to set me thinking about this, I just needed to abandon thoughts ...

Quote from: Prof;626161I think your fuel cut is another issue, it might be you have a chipped ECU - the only way to tell for sure it to lift the lid and have a look at the chip. The stock Mazda ones all seem to have a black label with silver/white letters and numbers on the EPROM chip.

See pic here for location of chip:

http://www.mazdarotaryclub.com/forums/attachment.php?attachmentid=23944&d=1159912639

I\'ll ask th old car owner which ECU is installed because of the missing passion to crawl in Foot well ...

Prof · July 14, 2009, 08:43:06 PM

Quote from: bMX;626165Ok, just changed the hoses from #1 - pressure sensor (solenoid).

Driving home after work will tell me if this could solve my issue :WaveBye

Prof, thank you to set me thinking about this, I just needed to abandon thoughts ...

I\'ll ask th old car owner which ECU is installed because of the missing passion to crawl in Foot well ...

Happy to help :cheers

bMX · July 14, 2009, 09:46:33 PM

Installed is the NON-chipped N380.

bMX · July 15, 2009, 10:49:22 PM

Ok, i changed the hoses from the boost control solenoid and now the max. peak is 0.62 bar (~9 PSI).

I asked the old owner of the car. There was installed a chipped N374 for testing before replaceing the engine. Actual installed ECU is the N380.

Prof · July 15, 2009, 11:30:19 PM

Glad you got the boost sorted

I think my old unchipped ECU was an N380 as well, and I\'m sure that did have boost cut.

Interesting thing though - if you keep the throttle at WOT, the fuel cut gets overidden within a second or two, and the ECU will just try and fuel like mad to keep up.