Outer Limits 4x4 Board

Hi All

I have recently put a G16A 16 valve MPI Vitara engine into my Sierra

I bought the motor as a halfcut and was connected to an auto box but I just used my 5 speed

The engine runs well but the engine light comes on when driven, the diagnostic code tells me it is a Vehicle speed sensor (VSS) fault. The VSS sensor gives the computer road speed info and is located behind the speedo cluster in the Vit but I can't use it in the sierra.

How do I solve this problem??

1. Trick the computer some how
2. Try and get a computer from a manual vit
3. Any other suggestions....................

Thanks
HR

use the electronic speedo sender as well as the vitra cluster

it may seem like a lot of stuffing around, but then you know you have instruments that are accurate to your motor..

the only problem this will cause is possibly a slight flat spot when ur cruisin down the road and ya wanna put ur foot down, and a slight increase in fuel economy, on the wide trac sierra dash there is a plug for it but not in the earlier ones, dont no about the coilies?, so in short i didnt hook mine up and have had no major problems.

the vss will be the speed sensor in the auto,u will have to trick it somehow

not sure if there is any difference between auto/ manual vitara speedo head but i know you can pull the speed sensor out of the back of the vitara speedo and fit it to the sierra speedo head. on mine there is a provision for the sensor on the speedo, its a 91 wt. clip sensor in and wire it up to computer.

will a manual g16a have the same issue if im not running the vitara cluster

bazooked wrote:the only problem this will cause is possibly a slight flat spot when ur cruisin down the road and ya wanna put ur foot down, and a slight increase in fuel economy, on the wide trac sierra dash there is a plug for it but not in the earlier ones, dont no about the coilies?, so in short i didnt hook mine up and have had no major problems.

Do run the auto computer?

I think that both manual and auto Vit's have a VSS built in to the speedo and the ECM uses it along with other signals to help control the ISC. The ISC works with the ECM to help control idle speed, improve starting, compensate air/fuel mix when decelerating and improve driveability while engine warms up and the auto has another VSS on the trans itself that inputs to an A/T controller seperate to the ECM. Anybody confirm this?

I recently changed my auto lwb vit to manual,and as for the electricals I closed the inhibitor switch circuit.At first i left the transmission module disconnected but found the check engine light to come on,so I plugged it back in and removed the overdrive light globe in the clusyer to sop it flashing.It has still gives great driveability,starts easy,no flatspots etc and gives better fuel economy

cj wrote:I think that both manual and auto Vit's have a VSS built in to the speedo and the ECM uses it along with other signals to help control the ISC. The ISC works with the ECM to help control idle speed, improve starting, compensate air/fuel mix when decelerating and improve driveability while engine warms up and the auto has another VSS on the trans itself that inputs to an A/T controller seperate to the ECM. Anybody confirm this?

Sorry what is the ISC?

sbfoot wrote:I recently changed my auto lwb vit to manual,and as for the electricals I closed the inhibitor switch circuit.At first i left the transmission module disconnected but found the check engine light to come on,so I plugged it back in and removed the overdrive light globe in the clusyer to sop it flashing.It has still gives great driveability,starts easy,no flatspots etc and gives better fuel economy

Which one is the inhibitor switch and what reason did you do this??

Thanks

HRZOOK wrote:

cj wrote:I think that both manual and auto Vit's have a VSS built in to the speedo and the ECM uses it along with other signals to help control the ISC. The ISC works with the ECM to help control idle speed, improve starting, compensate air/fuel mix when decelerating and improve driveability while engine warms up and the auto has another VSS on the trans itself that inputs to an A/T controller seperate to the ECM. Anybody confirm this?

Sorry what is the ISC?

Idle Speed Control - it's a solenoid valve on the throttle body that controls an air flow that bypasses the butterfly in the throttle body.

hrzook im not running any of the auto comp wires they all got the big chop, like i said earlier its not gonna make a huge difference to ur motor, alot of folk are runnin with out it.

just recientily did this to mine, you need to remove the speedo unit out of the speedo cluster and fit it into the sierra speedo head (direct bolt it fit)
will fit both NT and WT speedo's, the vitara's speed sensor is accually located in the speedo unit.

The new unit sends the signal out thru one of the two bolts that fastens the speedo unit to the cluster, so then attach the speed sensor wire from the ECU to this screw.

Also to detrmine which screw to use, follow the printed circurt board on the back of the vitara's speedo head unit......

hope that helps

pretty sure that the VSS wire is a yellow with another coloured tracer on it too

inhibitor switch lets you start the engine only when you are in park or neutral.

1 more question.....I hope

My Tacho isn't working with the new engine

There was a plug on the Vit loom the same as my Sierra that goes to the coil but it didn't make it work

What am I missing????

Thanks again guys your info has been

ok another question
if im about to try to run a manual g16a (16v inj) in my sierra, do i need the standard speedo or can i just piss it off ?

hey heath im pretty sure when i done my conversion i needed to piggy pack the 1.3 and the 1.6 wiring harness to get the tacho to work

ill double check and get back to your

heath

rgzook wrote:hey heath im pretty sure when i done my conversion i needed to piggy pack the 1.3 and the 1.6 wiring harness to get the tacho to work

ill double check and get back to your

heath

That what I was thinking

Piggy backing A to B

See pic below

that looks like that the one

Heath

rgzook wrote:that looks like that the one

Heath

Nope that didn't work on mine

Any other suggestions in regard to the Tacho?

i will have a look at mine tomorrow for ya and take a pic to.

bazooked wrote:i will have a look at mine tomorrow for ya and take a pic to.

You da mang

how did you go with the tacho wiring, did you get it sorted ??

Nope

Waiting on help from bazooked

hey dude, i was goin to take pix but i i sprayed all the wires with inhibitor and they are all red . but anyway ur wiring from the tacho should go to the negative side of the coil, there is also 1 extra wire coming out of ur puter for tacho signal aswell so we just cut it of , cause it wasnt needed.

benjamin78au wrote:how did you go with the tacho wiring, did you get it sorted ??

Got tacho going

These engines fly in a sierra

Good tech to install VSS from Vit into Sierra

http://www.azrockcrawler.com/_images/te ... otor2.html

Near bottom of page

Digging up this thread again.

There is some good tech in here, but I am curious about something. Is the VSS the same for all models? I have a G16b (16v multi point injected) and a mate has a G16a (8v throttle body injected). Would these both use the same VSS? What about the Jimnys, same again?

I can't see why they would need to be different but you never know.