my speedometer works once in a while. Check Engine light is on and the idle bounces

[holden j caufield]

with these symptoms it seems like a rather specific prob. Anyone had this before and know what the problem might be. The speedo works 1 in 4 times I start the car and the check engine is on after 30 sec and the idle bounces whenever I'm stopped. Thx

Edit 93 Prelude Si 2.3L 190K miles

 

[Black88GTA]

Year / Make / Model / Mileage / Engine / Transmission??

You'll get better / more relevant replies with this information...

Oh, and the surging idle thing is quite a common problem with older Accord / Preludes, and 90% of the time is a really simple fix.

 

[Heisenberg]

Make/model/year?

If it's a fairly modern car I'd say it's probably the vehicle speed sensor. Take it to an autoparts store and have them read the codes. That'll tell you a lot.

 

[Minjin]

Another good indicator for VSS is if the cruise control doesn't work.

 

[Pepsi90919]

the MIL is on. it is not worth guessing at any problem until a code is retrieved.

 

[holden j caufield]

93 Prelude Si 2.3L H23a

 

[holden j caufield]

bump

 

[thomsbrain]

failing vehicle speed sensor.

$250 to replace it at your mechanic.

very common issue in high mileage 90's hondas.

/thread.

 

[holden j caufield]

would a failing VSS cause a bouncing idle?

 

[OrganizedChaos]

Originally posted by: holden j caufield
would a failing VSS cause a bouncing idle?

i've heard that some fords use to use the VSS to determine when your coasting and shut the injectors off to save gas. perhaps you've got a similar setup.