1993 Civic DX Auto(tragic) close to 150,000 miles.
My mileage is
horrible lately , but what puzzles me is that the car fires up with great gusto. Turn the key and it seems to explode to life. Not even a single rev of the starter is heard. Every time.
Despite this, the car has always had
super weak yellow spark. I changed out the distributor and have new wires and plugs. The car is grounded well.
I don't get it.
For the longest time I had an issue with the car not starting when it was humid outside. It was extremely predictable that the next day that the car failed to start, it would be raining.
I changed out the main computer box - the ECU- and that fixed the problem.
I guess that having the windows cracked was letting in just enough rain to trickle down into the ECU. ( which is located in the passenger side footwell )
As I posted in a separate thread, I sometimes smell a gas odor in the cabin after a fill up ( No it's not coming from
me 
) I changed out the fuel pump when i had the ECU problem, and the seals around the access panel are in good shape. I'll update you guys next time I fill up, since i will check the seal then.
Now, onto the VSS problem . For the last few months, I have been driving around with a funtional speedometer, but a
non functioning odometer and trip meter.
Fairly recently, the speedo has stopped working as well. Sometimes it does, sometimes it doesn't.
I notice one of the things that makes it act strange is to go over railroad tracks.
When i do that, the speedo goes nuts and bounces all around. What could that be a sign of ? ( this is an automatic )
Today I replaced the VSS ( Vehicle Speed Sensor ) three times, and each one failed on me.
So to ask my original question, could an otherwise reliable car ( cranks right up every time ) be affected by a bad VSS to the point of losing 15 mpg ?
The transmission shifts at all the correct points and makes no funny noises at all.
I think i have a combination of things bringing my mileage down, but it just puzzles me that the engine fires right up and the transmission shifts fine as well.
Thanks guys. You are appreciated.