maft

[cantslowdown67]

Hi , I have a 88 Conquest Tsi and I just purchased a maft and a 3.5 inch GM Mas air. My question is, what wire from the factory harness do i connect the white wire to? There's also a purple wire that i have no idea were it goes! I put the MAS were the factory one was ,as a pull threw. Still trying to fine tune it, I have a Halmeter AF30 air/fuel meter and its not that accurate. Any help with the wire location and some tunning tips would be greatly appreciated! Thanks in advanced, Tony..

[96venge2.0]

Didn't it come with some instructions? White wire is tach signal and purple is aux switch. Not sure if that A/F meter is a wideband but to tune by the Maf-t a wideband is NEEDED. Just watch the wideband and turn the knobs accordingly. Don't let it run any leaner than around 14ish unless off the gas completely. Edited March 23, 2010 by 96venge2.0

[cantslowdown67]

Didn't it come with some instructions? White wire is tach signal and purple is aux switch. Not sure if that A/F meter is a wideband but to tune by the Maf-t a wideband is NEEDED. Just watch the wideband and turn the knobs accordingly. Don't let it run any leaner than around 14ish unless off the gas completely.

[cantslowdown67]

Thanks for the quick response, the problem is in the instructions it says not to connect the white wire to the coil so my question is what wire do I use to get the rpm signal? As far as the purple wire it doesn't say where to connect this wire at all. Im learning as i go along about these cars, I've only had this car for a few months. Thanks again, Tony.

 

 

[dstar88]

you do not use those two wires, just leave those two unplugged, folded away and ziptied back somewhere. the Maf-t will work just fine with out them.

 

i would definitely keep the a/f gauge from seeing 14 in boost. i would say 13 or lower while boosting. I noticed on mine that if it goes lower then 10 on the gauge, the engine starts to choke itself out and hickup. so i have mine sitting at around 13 under light boost, and when it builds up to 15+ lbs, it goes to around 11 or 12 due to the added fuel pressure.

 

when just cruising, you will never and should never see a specific #, it will always bounce around. Thats just how the stock computer is set up to do. Mine bounces around between 13 and 16 while cruising or driving normal. with the stock or 1g mass..that thing will bounce all over the place, i was seeing anywhere between 10-17 on the gauge.

 

for iddle, it just depends on how lean you want to make it. some people have their car iddling around 14-15. since there is no load on the engine, i dont think it will get hurt to have it iddle in the low to high 14's. I personally have mine iddling at around 13.5 -14. If i go any higher then that, the engine will start to pop a bit and annoy me. So that seems to be the happy medium for me.

 

 

 

Daniel

[cantslowdown67]

you do not use those two wires, just leave those two unplugged, folded away and ziptied back somewhere. the Maf-t will work just fine with out them.

 

i would definitely keep the a/f gauge from seeing 14 in boost. i would say 13 or lower while boosting. I noticed on mine that if it goes lower then 10 on the gauge, the engine starts to choke itself out and hickup. so i have mine sitting at around 13 under light boost, and when it builds up to 15+ lbs, it goes to around 11 or 12 due to the added fuel pressure.

 

when just cruising, you will never and should never see a specific #, it will always bounce around. Thats just how the stock computer is set up to do. Mine bounces around between 13 and 16 while cruising or driving normal. with the stock or 1g mass..that thing will bounce all over the place, i was seeing anywhere between 10-17 on the gauge.

 

for iddle, it just depends on how lean you want to make it. some people have their car iddling around 14-15. since there is no load on the engine, i dont think it will get hurt to have it iddle in the low to high 14's. I personally have mine iddling at around 13.5 -14. If i go any higher then that, the engine will start to pop a bit and annoy me. So that seems to be the happy medium for me.

 

 

 

Daniel

[cantslowdown67]

Thanks for the info..

[polarisman14]

FWIW this is what I learned from my experiences tuning and datalogging...

 

Stoich--14.7:1--is the ideal a/f ratio. When the engine isn't under load (IE idle) 14.7 is what you should aim for. When you're in any boost at all I would strongly suggest going to WOT fueling. For a conservative tune I'd go 11.5:1. If you're running race fuel and on the ragged edge, 12:1, but I would stay 11.5. On some cars it's normal for the programming to shut off the injectors entirely when the car is on decel. I would suggest running 11.5:1 when in boost at all.