# megasquirt aba... tps and rpm questions



## lroy12 (Jun 18, 2004)

I am running an obd2 aba in a mk3. I have megasquirt wired up to my system except i am running into some trouble. 
I have gotten my golf to idle roughly and the problems i am having are the following :
Where is a good RPM tach signal location?
My rpm signal is connected to the green and yellow wire coming out of my distributor, i believed this was my negative end on the dizzy so thought it would be a good tach signal... but it doesnt seem to give me my rpm when i idle








7 wire tps??
My tps is on my throttle body that has a total of 7 pins (for fidle solenoid i believe and tps all in one) i have the tps working backwards running of the stock ecu voltage reference... what should i do to correct this backwards tps issue?
thanks for reading


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (lroy12)*

what type of dizzy are you using


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*

Well the TPS and the IAC stepper motor have to be wired as two seperate things. You will need a wiring diagram to know how to wire it up.
Is your megasquirt a MS-1 or MS-2? What version PCB did you use?
I am using a V3 PCB with MS-1 using the MSnS-E code. I am going to use the VR (CKP) sensor for tach input and spark timing. I don't think you can use the hall sender for that as the ABA hall only has 1 window, or 1 signal per revolution of engine. That is good for indication of engine speed (gauge cluster tach) but it doesn't give the ECU much info to work with for deciding when to spark. You need to use a digi2 dizzy with a 4 window hall, or a VR sensor. I recommend the VR sensor because it is already there.


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (GodSquadMandrake)*

i do have the wiring diagram and for the tps signal i get a voltage reading of 0-11 and i know ms likes a 0-5v reading. how do you have yours set up?


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*

i have the same setup as you but i have a 96 golf with a xflow aba


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*


_Quote, originally posted by *qbngolf* »_i do have the wiring diagram and for the tps signal i get a voltage reading of 0-11 and i know ms likes a 0-5v reading. how do you have yours set up?

Actually I haven't wired it up yet lol


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (GodSquadMandrake)*

im wiring mine up tonight we will see how it goes. i had installed it last weekend but i wasnt getting an rpm signal. so i had to revert it back to stock. all the wires are there though so it should be a snap. oh and ps.. ive been doing alot of research and i dont think the engine speed sensor is a vr sensor. i think it is a hall sensor. thats how i have mine wired up with a few mods to the board

_Modified by qbngolf at 5:30 AM 2-24-2006_


_Modified by qbngolf at 5:33 AM 2-24-2006_


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*


_Quote, originally posted by *qbngolf* »_oh and ps.. ive been doing alot of research and i dont think the engine speed sensor is a vr sensor. i think it is a hall sensor. thats how i have mine wired up with a few mods to the board


That's what I have heard too but I was thinking that it's impossible for it to be a hall effect sensor. There is no hall field generated!


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (GodSquadMandrake)*

read this 
http://msefi.com/viewtopic.php...rt=12
and this
http://forums.vwvortex.com/zer...ge=28
im wiring this up tonight and i should be done tomorrow morning. ill let you know how it goes
read this sh*t and read it good. i mean click on the links too. i think i am just getting lucky putting the ms in at the right time because these are recent posts of people figuring this out


_Modified by qbngolf at 10:03 PM 2-24-2006_


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*

I read that. I'm still in denial that it's a hall sensor because I built my MS for a VR sensor.


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (GodSquadMandrake)*

well had to wire it up as fuel only because the sensor didnt want to cooperate with me. gonna pick up an audi 80 dizzy i think and the tps is givin me some funny voltage i can get it pretty good with resistors but i think since i had to cut up the cts and iat sensor the signal got screwed up somehow because when i depress the throttle a half an inch, ms says i have it depressed 100%. i see that these sensors are wired up to each other in the bentley maybe this has something to do with the problem. what do you think


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*

Well from what someone else said the TPS gives off 11v at ful throttle, and MS expects 5v. So it would make sense that half throttle seems like full throttle to megasquirt.


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (GodSquadMandrake)*

yeah but i ran a resistor in line with the tps so i measured voltage at wot and its only 4.5 volts. my thought is its reading that same voltage at half throttle also though


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*

Oh you could be right. I don't know enough about it though. Is it possible to use your multimeter at half throttle?


----------



## qbngolf (Sep 22, 2005)

*Re: megasquirt aba... tps and rpm questions (GodSquadMandrake)*

screw that sh#t. i bought an obd1 throttle body. too much of a hassle that stupid throttle body has seven wires. there is a tps wire that is five volts but it reads five volts at closed and 0 volts at wot so i said screw it, im sick of screwing around. just want to get these sensors running right. dont want to spend hours [email protected] around. i mean it would be ok if the car could just sit there but this is my daily driver


----------



## jetta gli (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (qbngolf)*

i have been running ms on my aba xflow for about 6 mouths and about to put a k26 turbo on it anybody have any tips for me


----------



## GodSquadMandrake (Feb 17, 2004)

*Re: megasquirt aba... tps and rpm questions (jetta gli)*

Anybody got that wiring diagram of the OBD2 throttle position sensor?


----------

