yes another maft pro question

[808mkiiisupra]

heres my setup. 550s walbro fp set to 27ish with vacuum connected. i dont have any provisions for a factory 02 sensor so its unplugged.

I just got my car running and here are some issues. at idle it is running real rich at about 10.5-11 on my lc-1. aux 1 is another issue. Sometimes it reads 2.0volts and then sometimes it doesn't real anything (.01). but after warm up if i hold a constant rev at around 1700rpms it revs back and forth to 1400ish rpms. While the rpms jump the aux1 reads 2.0 then .01 volts then back to 2.0 ect.

Let me know if you guys have some experience with this thanks a lot!

 

[arizzle]

have you tried pulling fuel out with the main scale?

 

[Sawbladz]

Do you have any codes?

 

[MA70Snowman]

what version are you running, what are your settings? your symptoms describe numerous problems. What is your static FP? 27ish w/ vac.. well your vac could be any number so we don't resonably know what your baseline is. The MAFT pro is a finky beast at best, but when we don't have any information its hard to assist.

 

[89supra7mgte]

What do you mean exactly about the o2 sensor?

 

[808mkiiisupra]

yea i have tried pulling from mainscale (-25 for 550s') and it does lean out more. im getting codes 21 and 24. using version 5.11. fp is about 37psi with vac line disconnected. and also factory 02 sensor is disconnected completely. using wb for the afrs.

 

[89supra7mgte]

I dont know exactly how the maft installs as far as wiring goes, but doesnt the computer still need to see some sort of o2 reading? Or is the wb tied into factory wiring also?

 

[GrimJack]

I dont know exactly how the maft installs as far as wiring goes, but doesnt the computer still need to see some sort of o2 reading? Or is the wb tied into factory wiring also?

The MAFT Pro needs to see the WB output. The stock ECU still needs to see a narrowband output. Furthermore, the heater circuit for the original narrowband needs a resistor installed in it to prevent the ECU from thinking it's dead.

 

[CajunKenny]

Double and TRIPLE check all of your connections AND settings! Search fullthrottletech.com for the latest instructions. Also, Doward has a really nice beginners writeup on mkiiitech.com. Search on ‘Maft Pro’.

Once you’ve done the above, set your fuel pressure per the TSRM.

Make sure your LC-1 is calibrated correctly.

As far as ‘Mainscale’ set it to 0 for now.

For now let’s forget about the vf signal. What are your ‘Op-Temp’ idle afr’s?

Are you Speed Density? (I don't like to assume)

 

[808mkiiisupra]

yea im sure the connections are good. they are soldered. Normal Op temp afrs are around 10-11ish. Fuel pressure is tsrm specs with and without vac line connected.

 

[CajunKenny]

Are you Speed Density? (I don't like to assume)

Try pulling the mainscale down to -15 and then work your idle using the VE Table. Once idle AFR's are close, then try to make your Vf happy.

Leaving the mainscale at -15 will leave you pretty safe for the rest of your tune.