2G Speedometer is jumping all over the place.

[JMiller]

Got in my car to drive to work and hit fuel cut while i was just cruising, so i start checking my gauges and look down to notice my speedometer just bouncing all over the place (when it hit 160 it would cut fuel). At a red light i free revved and the speedo jumped some more. I checked a few threads and have been lead to believe that i need a new VSS.
Thanks in advance.

 

[SexperT]

Try replacing the speed sensor that attaches to the trans (VSS), it tells the ECU (in 2gs its electronic, in 1gs its a manual one) the speed of the car, hope this helps.

If that's not it, you can always return the part

 

[Maverick4g63]

I had the same problem last week. Luckily my sensor had somehow worked itself loose. Check that before you buy one.

 

[KMOSES]

Try replacing the speed sensor that attaches to the trans (VSS), it tells the ECU (in 2gs its electronic, in 1gs its a manual one) the speed of the car, hope this helps.

What this guy said, I just had the same problem, my speedo was jumping all over the place, then it finally quit and just went to 0, I drove it around for awhile just using the tach until i could get a new VSS.

It's a pita to get to, and make sure you have a magnet or something to get the bolt so it doesn't fall into the trans, I dropped mine but and it landed on the edge of the hole into the trans. I got very lucky.

I got the speed sensor from the dealership, just under 100 bucks, and reused the gear from my old one.

Part Number: MD756606 for the 2g.

 

[JMiller]

One more question, would a bad VSS cause fuel cut when the car is boosting normally?

I run 15psi on a T25 and if I go more than 60% throttle I hit fuel cut, problem started the day my speedometer messed up.

 

[SexperT]

Read; http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/186971-what-fuel-cut.html

Its DSMtuners Fuel Cut post, if the VSS is not causing it, chances are one of these things are. If you have not done any of those things and turns out your VSS is causing it, i would think the high velocity output from the VSS is tricking the ECU into speed limiting (130mphs).

Read more about speed limiter here;
Warning!!! This Mod Is Extremely Dangerous!!!

Hope this helps

 

[JMiller]

Well i ordered a new OEM VSS and Speedo gear so ill see next week when i get it in.

 

[JMiller]

I got everything in the mail monday and after doing some research i think they sent the wrong gear shaft. The car is a 98 GST manual, here's what i got.

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Thats as far in as it will go, is it right or wrong?

 

[Alex7747]

Yep that looks like the right one. The manuals have a shorter shaft while the autos have a longer shaft. You have the manual (short shaft) so you're good to go .

 

[Hortanica]

i know you have already ordered new stuff anyways, but a friend just had the same problem, and all it was, was the connector was loose on the VSS, I just reconnected it and put a metal clip to hold it on, and its been fine since.

 

[JMiller]

Yep that looks like the right one. The manuals have a shorter shaft while the autos have a longer shaft. You have the manual(short shaft) so you're good to go .

Well the manual ones I've been seeing on here don't show any of the shaft, wont know until Friday when i can put it in though.

@Hortanica
I figured its a 14 year old car might as well replace it now when i have the money for it than have it really break later and not have the money for it, if that makes sense?

Got this from another post, i looked at my receipt and the SKU shows they sent me the one in bold and the site doesnt have an option for anything, it just says "OEM Speedometer Driven Gear: Mitsubishi Eclipse 95-99"

For future reference...

The sensor comes separate from the shaft/gear (which come together). The sensor also comes with an o-ring and e-clip.

These are all 2g part numbers.

FWD M/T (all years), and AWD M/T 95-96::
Gear - MD746492
Sensor - MD756606

FWD A/T (all years), and AWD A/T 95-96::
Gear - MD757055
Sensor - MD756606

AWD M/T 97-99:
Gear - MD749150
Sensor - MD749149

AWD A/T 97-99:
Gear - MD760150
Sensor - MD760149