| Author | Message | ||
     Mike Goodell (Mikegoodell) Member Username: Mikegoodell Post Number: 76 Registered: 11-2002 |
What are the symptoms of a failing VSS? I have an intermittent problem, it almost feels like the engine is cutting out for a split second while driving. The engine makes good power, no nasty noises, and sitting still and revving it there are no cut outs or indications of a problem. I swapped the fuel filter yesterday with no effect. I tried an archive search for VSS but found nothing that helped Mike G. 96 Disco SD | ||
| Mike Goodell (Mikegoodell) Member Username: Mikegoodell Post Number: 77 Registered: 11-2002 |
After extracting my cranium from my anal orifice I figured out how to do a proper archive search and it appears that the VSS is going to be the culprit. Mike G. 96 Disco SD | ||
| Robert Pate (Racerx) New Member Username: Racerx Post Number: 3 Registered: 08-2003 |
Mike I had the same thing going on for about two years. No could tell me what it was not even the dealers. Im trying to remember what I changed either the TPS or the VSS. It was down on the trans case but it worked no more cutting out at freeway speed. | ||
| Todd Juneau (Toddxd) Member Username: Toddxd Post Number: 100 Registered: 11-2002 |
it definitely sounds like the VSS. I had the same issues on my 97D1. Purchased a new one, intalled in about 15 minutes, and presto...no more problem! | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 995 Registered: 09-2002 |
Mike, same thing happened on my 96 twice, both times it was VSS. | ||
| trevor griffiths (Trevorgriffiths) Member Username: Trevorgriffiths Post Number: 142 Registered: 11-2002 |
It's funny how the VSS does not set a MIL (aka check engine light), unless it goes out completely. I have had one confirmed fix and 2 undiagnosed vss potential failures in the last 2 weeks come through the shop. On a test drive with a scan tool, the vehicle speed would suddenly go from 63mph to well over 100mph, enough to trip the speed limiter in the ECU. A graphing program showed a lot of 'noise' as well as inconsistent dips and spikes. the new sensor was smooth up and down with vehicle speed. | ||
| andrew adia (Drew) New Member Username: Drew Post Number: 31 Registered: 03-2003 |
Trevor, You may have a third undiagnosed vss failure. I'm glad to see your always on top of your game. Are you going to be at the shop on Fri? Drew | ||
| Keith Armstrong (Keith) New Member Username: Keith Post Number: 6 Registered: 02-2003 |
I just started looking for this discussion this morning! While parked at the post office this a.m. my speedo started bouncing from 0 to 30 mph! Is this the VSS too? I don't have the surging at speed symptom  | ||
| Randall Smith (Mr_smith) New Member Username: Mr_smith Post Number: 35 Registered: 04-2003 |
I don't think the ECU pays much attention to the vehicle speed unless you are going to fast, or not moving. The speedometer and cruise control system do use the VSS sensor's out put. Randall | ||
| Mike Goodell (Mikegoodell) Member Username: Mikegoodell Post Number: 78 Registered: 11-2002 |
So far I can get maybe 3-5 miles of travel before I get the surging/cut out. I've got a new VSS coming from Nathan at Discount Rovers, so hopefully this will cure my ill's. The thing that realy gets me about it is the fact that I just changed all the fluids under the rig. Maybe the VSS doesn't like fresh 80-90wt. Mike G. 96 Disco SD | ||
| Jordan Pettigrew (Klecko) New Member Username: Klecko Post Number: 28 Registered: 05-2003 |
I had same symptoms. On long drives on very hot humid days I had this cutting out as well. Recently changed TPS and this has eliminated the problem. | ||
| Danno (Danno) Member Username: Danno Post Number: 245 Registered: 08-2002 |
keith, your problem is that your in KS. | ||
| Eric Dennis (Dcdisco) New Member Username: Dcdisco Post Number: 19 Registered: 07-2003 |
hey guys what is the tps vs. the vss... i assume the vss is the vech. speed sensor what is the other .. i have had this happed to me last weekend going up 2 ct. around 70mph after going for about 2hrs45 min non stop and once pulling out of toll both 2 days later at about 70mph it started to lose power but no MIL.. no rpm jumps or strange shift patterns?? valve job at 88k no other troubles.. Sorry i missied ya trevor on friday was the air dam ok for ya.. Eric | ||
| Keith Armstrong (Keith) New Member Username: Keith Post Number: 7 Registered: 02-2003 |
Nope Danno, still avoiding KS and in Iowa  Oh well, no repeat performances to date. I'll have to wait until it's a more regular occurance. Interesting experience w/ the new front trutrac though. After alignment it still drove to the left. After an extra 5psi in the left front, the straying from straight ahead is gone! Cheers. | ||
| Bruce Potier (Brucep) New Member Username: Brucep Post Number: 28 Registered: 06-2003 |
Keith, this is one area, tire pressure, that will get your attention with TTs in the front. I can feel 3PSI difference pulling left or right. I think it has to do with the TT applying more traction to the tire with lower pressure and combined with effects of a lowered PSI tire, it tends to pull towards that lowered tire PSI. What is really wierd is if you ever drop your front drive-shaft, the steering feels really loose and one has to be careful at highway speeds. | ||
| Mike Goodell (Mikegoodell) Member Username: Mikegoodell Post Number: 80 Registered: 11-2002 |
Just a note to everyone who thinks they may have a VSS problem, Do something obvious first, check your plug wires!! Ask me how I know!! It's always the simple things that get you. Marginal plug contact,engine warms up, wire moves, instant speed limiter!! throw in normal engine vibrations and it becomes an intermitent problem just like the VSS symptoms. Well at least I'll have a new VSS on hand for "next time" Mike G. 96 Disco SD | ||
| Rod Salter (Rmsalter) New Member Username: Rmsalter Post Number: 1 Registered: 08-2003 |
Hi, Have a 96 Discovery that losses power off and on for about a mile then then runs fine for a few miles. It does this at higher speeds (35mph and up) at first, but once it starts lossing power it will do it at as low as 20mph, whether the engine is hot or cold. Twice in the last month, after driving it 3-4 miles it has stalled at red lights, but it starts right back up. Can a bad VSS send mixed signals to the computer even when the car is at a red light? What's the diagnosis? | ||
| Mike Bauer (Mikeb) Member Username: Mikeb Post Number: 88 Registered: 02-2003 |
I just started experiencing the same problem this weekend on a 98 Disco. It only happens after driving a couple of hours. I did notice that the problem goes away if I turn the truck off for a bit (like to re-fuel and take a break!) I plan to replace the VSS this weekend and the fuel filter. I don't know if this is comforting or not, but according to the dealership guy, a bad VSS will not leave you stranded on the side of the road. Thanks, Mike B. |
