bad throttle position sensor = won't start?

[bosango]

Hey Subers,

 

My 1993 Legacy LS was running great until I tried to start it yesterday.  It turns over fine, but behaves like it's not getting any gas or spark.  I checked both of those possible causes and those systems seem to be working fine.  The timing belt only has about 10,000 miles on it and as the engine turns over it doesn't cough or sputter or make any obvious timing belt related noises.  I checked the timing as it was turning over and #1 is firing at about 12 BTDC, though I 'm not sure that means anything for an engine that isn't running.  I checked the engine code and got #31 (faulty throttle position sensor) - not a cheap thing to replace.  So, is it possible that the the car would run fine one day and all of a sudden the TPS is bad the next?  If that's possible, could it cause the car to not start?  I haven't tested the TPS yet because I cleverly destroyed my multi-meter by not paying attention to what I was doing last time I used it.

[gbhrps]

bosango,

 

Its possible the the TPS failure is at a position on its arc of travel that doesn't allow sufficient fuel to be injected to enable a start.

 

But before you buy a new TPS, I would get a good mechanic to diagnose whether this indeed is the issue, or just a bad connector or bad harness. There is no sense throwing money at an issue if that doesn't solve the problem. Good Luck!

[Fairtax4me]

How do you know its getting fuel?

Have you tried spraying starting fluid into the intake to see if it will start?

[logic23]

also check the ignitor ... they have tricked me a couple times

[sirtokesalot]

im pretty sure mine runs with that sensor unplugged. i learned this unplugging things one day trying to find out if it would run better with somtihng unplugged when i was having running issues.