questions about maf conversion
 

im gonna redo the maf wiring because its a ****ty job and frankly i think it needs to be done over again. i bought this wiring kit : http://cgi.ebay.com/ebaymotors/ws/eB...863639550&rd=1 and am following these instructions : http://www.stangnet.com/tech/maf/massairconversion.html

everything is self explanitory but i just need to know one thing. it says i have to splice wires into the fuel relay and the vss. will these wires hurt performance if they're not hooked up? the instructions say it might. these 3 wires are not done when my car was converted to maf. im not sure if the thermactor pins were moved because it started raining before i got a chance to check that. bascially im going to rewire the whole conversion, but i just was wondering if those things not being hooked up will hurt performance.

reason im redoing it (besides a ****ty job) is because the cars been giving me a big headache for the past month or so and the other day we discovered that the power wire for the maf had been stripped of its insulation where it meets the firewall because the fool that did it didn't use a grommet and barely made the whole big enough for the 4 wires :mad: sorry for the long post, just aggrivated with this crap.

cliff notes: ****ty maf conversion by previous owner. do the vss and fuel relay additions to the ecu for the conversion matter?

Matters?
 

Yes sir! the VSS is very important, it is the Vehicle Speed Sensor, and it is a critical part of MAF Conversion.....heres why....when you convert to MAF, something has to tell your new computer that the vehicle is moving, this was not needed with SD, as it uses set parameters. And the fuel relay is your fuel cutoff for the 6250 redline/fuel cut-off, both are needed.

Jay

thanks for the info!

I went to gonzalas today, I should have looked you up. If you or any one you know saw a lime green mustang with weld wheels and a darker back hatch, that was me. I went to JOE HEBERT's place.

on a side note i have driven aournd without the VSS in the tranny on a MAF conversion car with no adverse side affects so i guess its a hit or miss?also did you plug the old MAP sensor or did you go out and grab a BAP from a MAF car?

i have the vacuum off but the hole open. i was told to do that by a few people, plus if ordering a bap i'd need some numbers that i didn't know how to get. i was told by the instructions for the converion and a mustang shop just to get a map sensor and leave the vacuum off.

see thread :
http://forums.mustangworks.com/showt...threadid=30284

The VSS only does two things. It senses that you are still moving so that when you are rolling up to a stop that it can keep the revs up to prevent stalling. It is also used for cruise control.

The computer controls the rev limit by cutting fuel and spark to the cylinders. It does this by just not opening the injectors. It doesn't cut off the fuel pump via the fuel relay. The connection to the fuel pump relay is only used to make sure that the fuel pump is working properly. If it's not, the computer can cut off spark to prevent you from running too lean and destroying your engine.

That is 100% correct for this application. Overall, the VSS serves 4 purposes. It is important for cruise control and the IAC solenoid, as mentioned, and it also affects the transmission torque convertor lock-up, as well as the electric cooling fan, where applicable.

:)

Take care,
~Chris

Thanks for the addition, Chris. Since I have a manual I tend to answer things from that perspective.

Jim
You were right on the money! His car is a manual, and doesn't have the factory electric fan either. I was just mentioning those other two functions for reference. Sorry if it came across wrong. You did a great job, like always!

:)

Take care,
~Chris

I didn't think you were correcting me or anything. I'm glad you made the addition. I like to give complete answers for those that may be looking on. As you said, for reference. If you didn't make the addition, someone with an automatic that was looking for answers could have made a bad decision based on my incomplete information.