HELP... MAF Sensor problem...

brutus.nova · Oct 23, 2009, 08:34 PM

Just did the first start of the lancer after doing the turbo build and it fired and then died... Well after a thorough double check of everything started troubleshooting... Unplugged the MAF Sensor and it started and idled just fine. Then plugged it back in and insta died... Is it cause i have a stock MAF? It is still right by the intake. Is that wrong? Please help... Tuner appointment is tomorrow/

link62 · Oct 23, 2009, 08:53 PM

what setup are you running and it shouldnt be the problem im still running a stock maf

brutus.nova · Oct 23, 2009, 09:32 PM

running a TO4b with stock map, 450cc injectors, APEXI II SAFC. Where did you put your stock O2 Sensors after you changed your down pipe? Do you know any settings on the SAFC that would affect the MAF? When we took the MAF off the intake and plugged it in it worked. But as soon as we put it near the intake it starting idleing like ****... Hyper sensitive...

4g94T · Oct 23, 2009, 09:33 PM

reset the ECU and try again

link62 · Oct 23, 2009, 09:38 PM

^i agree try that and see what happens

brutus.nova · Oct 23, 2009, 09:54 PM

that didnt work but there is a check engine light. my friend is bring the code reader right now so i will let you know what codes pop out when he gets here. I put the first O2 Sensor about 33 inches from the turbo with the wide band sensor. then the second went right before the cat just like it was with the stock exhaust...

ThunderOZ · Oct 24, 2009, 01:44 AM

Why did you put the O2 sensor for far away? And by intake, you mean the portion going into the compressor housing of the turbo or near the throttle body? Have you adjusted for the larger injectors? Are the 450cc injectors the right impedence?

link62 · Oct 24, 2009, 02:03 AM

having re reading is post it sounds like he has his maf on the up ic piping and not in the compressor side of the turbo

03lances · Oct 24, 2009, 02:06 PM

Quote:

Originally Posted by ThunderOZ

Why did you put the O2 sensor for far away? And by intake, you mean the portion going into the compressor housing of the turbo or near the throttle body? Have you adjusted for the larger injectors? Are the 450cc injectors the right impedence?

This is my question, it almost sounds like he has the maf close to the engine where compressed air is. If so it needs to be moved before the turbo not after

03lances · Oct 24, 2009, 02:21 PM

Wait I thought we were supposed to put the first O2 sensor in the O2 housing.

brutus.nova · Oct 25, 2009, 07:20 AM

well after a full day of troubleshooting and trying all the things you guys suggested. I was able to get a hold of my tuner Fred at SMG Motoring and he figured it out. The BOV that I used was sucking in air and that air was getting to the intake without the MAF knowing about it... So that was causing the idleing problems. so a little tuneage and the idleing was fixed. Then the dyno was succesfful ~ 165 HP, @ 165 lbs of torque with three pounds of boots...

Thanks for all the quick replies i went right to my garage and tried them when they were posted... Take care...

ThunderOZ · Oct 25, 2009, 10:43 PM

Was that a typo or did you really mean 3 psi?

link62 · Oct 25, 2009, 11:03 PM

i still would like to see pic or ur setup

Sicktght311 · Oct 26, 2009, 07:20 AM

Quote:

Originally Posted by ThunderOZ

Was that a typo or did you really mean 3 psi?

Makes sense with the HP readings. He's probably just running low boost until everything is set up and working properly.....you know......the right way to do things with a custom kit.

And FYI, two things (they're in the sticky i created at the top of the page too).

On the lancers, you HAVE to have the MAF on the intake side of the system, NOT the pressurized side. Even with an SAFC, you wont be able to control the fuel trims in closed loop mode and the car will run lean. If you have it on the intake side, make sure the BOV is recirculated into the intake tract AFTER the MAF. The order of operations should be filter-->maf--->BOV recirculation port--->turbo. The maf on the lancers cant read pressurized air correctly, and when you start boosting in closed loop, while the ecu is trying to correct your fuel trims, it will lean out. Big no no

ThunderOZ · Oct 26, 2009, 11:42 AM

I don't think that 165whp on a turbo like that at 3psi makes sense. What size is it? If it is the td04 I'm thinking of, it's like a 13a from a dsm, tiny in otherwords. I didn't even know you could get a wastegate spring that low...