In need of help with speed sensor

[wulffman]

I'm stuck!

I bought a 1992 Jeep YJ for my son and I to rehab for his 16th birthday

Wen we bought it the speed sensor was broken off. We bought a new speed sensor, installed it and now the jeep sputters and want to die and idles rough.

When we disconnect the speed sensor it runs great. It is an electronic speedometer, not cable. I have three wires. One reads 0 volts, one reads 5 volts and one reads 9 volts. I connected the wires according to the diagram that came with the speed sensor and wiring harness.

when I switch what i believe is the power supply wire and the wire to the speedometer the jeep will not start at all.

could the fix be as simple as replacing the speedometer?

The jeep has had a brand new engine, new starter, new fuel filter, all lights, wipers, dimmer, switches, gauges and even the tachometer are all working.

any help would be greatly appreciated!

 

[JPNinPA]

Welcome to the board.

What engine 6 or 4 cyl? Do you know what year make model the engine came from?

The speedo is on the transfer case and is comprised of a gear and electronic component. The gear is exchangeable and sized to match your rear gearing and tire size. Based on the size it needs to be indexed so the speedometer reads correctly. The speed readout is also used by the PCM. If the rpm, speed and other sensors do not match the engine may not operate appropriately.



Check this site about gearing and indexing. It's for a tj but the process is the same.

http://www.stu-offroad.com/engine/speedo/speed1.htm
http://www.quadratec.com/jeep_knowledgebase/article-46.htm

 

[Bounty__Hunter]

I think the OP is more wanting to confirm the wiring of the VSS.

JPN, your pic is of a rare breed, it's a speed sensor that feeds both a mechanical speedo and an electronic signal to an ECM. Maybe off a Renix powered Jeep?

 

[wulffman]

JPNinPA - The engine is a brand new 2.5L 4 Cyl
Tire Size = 31"
Speedo Gear = 41 Teeth

Bounty_Hunter - The picture above looks like a mix of what was found on the transfer case when I bought the jeep and what a new one purchases at autozone looks like. I believe the previous owner tried to glue the pieces together.

I have attached pictures for everyone.

Any help getting the speedometer working again would be greatly appreciated.

Pic 1 = Old Speed Sensor and housing that I removed
Pic 2 = New Speed Sensor that I installed
Pic 3 = Front of Speedometer / Tachometer
Pic 4 = Rear of Speedometer / Tachometer
Pic 5 = What was left on the transfer case when I purchased the Jeep










If there is any other information needed please let me know.

Thank you

 

[wulffman]

How would I know if it is a Renix powered jeep ?

 

[JPNinPA]

It looks like two sensors are available for that year.. Not sure on what distinguishes which is used. https://www.rockauto.com/m/mobilecatalog.php


Auto or manual?
Rear gearing ??? 4:56

Have you verified it was clocked correctly?

 

[wulffman]

It is manual.

The transfer case tag says it is a model 231 J
ratio 2.72

 

[JPNinPA]

It is manual. The transfer case tag says it is a model 231 J ratio 2.72

Gearing would be on a tag on the rear pumpkin. Usually upper right.

 

[wulffman]

4.11

 

[Bounty__Hunter]

 

[JPNinPA]

Have you verified the gear is clocked correctly?.
The speedo output is used by the PCM and if not clocked correctly the gear doesn't spin all the time. When this happens sputtering and stalling will occur. If you had a auto trans you may even have erratic shifting issues.

Based on the gearing and tire size you should have a 37 tooth gear to read correct speed.