Ford Mustang Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
1,454 Posts
Discussion Starter #1
when i did my mass air conversion, i did not hook up the VSS signal wires, and my car was stalling all over town, it really got to me so i decided that i should do it today, and man what a difference it makes

some of you might remember a post i made a while ago about me not being able to chirp 2nd gear, well thats no probalem now, because my idle hangs longer now that i have hooked up the wires, before it used to drop fast, so i guess thats why i couldn't hit 2nd....

my car feels much stronger and shifts awesome, so to all those who did not hook up the VSS signal wires, do it!!!
 

·
Registered
Joined
·
2,548 Posts
very interesting.. I never did that.. or the FP relay either.. been about 8 years since I converted too.

Glad to see it worked for you, maybe soon I'll do mine, since I want to replace the carpet anyway.
 

·
Registered
Joined
·
291 Posts
i never hooked mine up either, and i've been stalling all over the place. my car did not come from the factory with one, as i do not have cruise control. does anyone know where to get a VSS from? how does it get connected? thanks for any help, i really need to get one hooked up.

~Paul
 

·
Super Moderator
Joined
·
27,653 Posts
Your car has a VSS whether it has cruise control or not, because the computer uses it to know whether or not the car is moving so it knows to hold the idle up until it's nearly stopped. It's connected to the speedo cable right as it enters the drivers side of the trans.
 

·
Registered
Joined
·
527 Posts
I'd also like to know...I have an 87 converted...with no cruise control...thanks!

Scott
 

·
Registered
Joined
·
1,401 Posts
Same thing I went through... glad you finaly did it! My car was stalling at almost every red light or stop sign, once hooked up, car acted totaly different... just how it was supposed to, more power, more responsive, and didn't stall.
 

·
Registered
Joined
·
1,454 Posts
Discussion Starter #8
i took this from the corral tech article

"There is a differential signal called VSS (Vehicle Speed Sensor) which comes from a small sensor on the transmission where the speedometer cable is connected. In 1986-1988 MAP cars this signal was used only by the cruise control and the sensor may not be installed if your car does not have cruise control. In MAF cars, this signal is used by both the cruise control and the EEC-IV. The wires/pins for these signals are not physically equipped in a MAP car's wiring harness, which will yield an error code for NO VSS SIGNAL- (code 29) from the continuous memory codes in the EEC-IV. These signals are not absolutely needed, though some people have reported stalling when coasting to a stop without them. You can hook the VSS signals up to the EEC-IV connector by connecting the input pins of the EEC to the appropriate wires on the cruise control module (located just to the left of the clutch/brake pedals). You need to hook the dark green/white wire going to the speed control to pin 3 of the EEC, and the orange/yellow wire to pin 6 (these are the colors for an '88, anyway). These positions on the EEC connector are empty and will require 2 EEC-IV connector pins."

if you did not hook it up, get out there and hook it up, because you will never regret it, the car feels very different now when i shift, and it feels more powerful, i wouldn't be surprised if doing this took a tenth or two off my 1/4 mile time :)
 

·
Registered
Joined
·
1,401 Posts
MFE, the only cars that did not come with VSS lines were speed density cars with out cruise. I have an 87' GT that doesn't have cruise and I had to add the VSS sensor itself down on the trans, change the speedo cable, and add the two wires to the computer. All Mass Air cars came with VSS as it needs to be there for that computer, Speed Density however does not, so if you didn't get cruise on your SD Mustang (87-89), then you didn't get VSS lines and need to add them in an event of a MAF conversion.
 

·
Registered
Joined
·
1,401 Posts
I don't know about the whole cruise control module next to my pedals, I don't have one. When I did it, I just hooked one of the wires up to Pin 3 and the other to Pin 6 just as you said... doesn't matter which wire goes to what. You will have to add and run these wires to those of you who are in the same boat.
 

·
Registered
Joined
·
1,454 Posts
Discussion Starter #11
right, you also need 2 pins that go into the EEC connector, i got mine from my fathers shop, you can get them off any car harness, you might need to modify them like i did, mine were too big...
 

·
Registered
Joined
·
1,401 Posts
My VSS wires and pins that were already connected to the wires came with the Pro-M mass air conversion kit that was something like $39 that came with the MAF pigtail and the pin re-location instructions
 

·
Super Moderator
Joined
·
27,653 Posts
Hey, you learn something new every day. I wonder how the SD/non-cruise cars handled cruise idle?
 

·
Registered
Joined
·
1,401 Posts
I totaly agree with you MFE... I just don't know. I was shocked when I did my conversion and I didn't have it. What a pain... had to get a new speedo cable and the sensor. Ford dealer doesn't know the difference between the headlight bulb and the engine, so it was like pulling teeth trying to explain to them what I needed when I didn't even know along with them not knowing what size speedo cable because for some reason Ford decides to build the same cars with like 5 different sizes evidently. Anyway, it was expensive and a pain. Other than that, night and day difference.

What I don't understand is WHY the computer needs to know how fast you are going. Doesn't make sense to me... seems like all it does is buffer the throttle a little so that the RPM's fall slower so that it's easier to shift... doesn't make sense to me why it wouldn't stall while you were driving and pop it into neutral while coasting... I guess it's convienient to stall when you are stopped, but still. Guess that's just the way it is though.
 

·
Registered
Joined
·
1,454 Posts
Discussion Starter #15
WA2FAST said:
What I don't understand is WHY the computer needs to know how fast you are going. Doesn't make sense to me... seems like all it does is buffer the throttle a little so that the RPM's fall slower so that it's easier to shift...
i think thats what it is there for......at least thats what i always thought unless someone can change my mind
 

·
Registered
Joined
·
1,401 Posts
Yes, you will need a new speedo cable. Reason is because the one that you have now is designed to be plugged directly into the trans. The ones that go into the speed sensor have smaller ends to fit into them. The speed sensor is like a piggy-back sensor that goes between the speedo cable and the speedo gear. I am prety sure that the speedo cable and the sensor are Ford dealer only parts.
 

·
Registered
Joined
·
47 Posts
pull the vss out of a tbird /cougar/ mark most came with cruise and the cable will fit can also pull wiring and plug off same car!

carl
 
1 - 18 of 18 Posts
Top