> i got a 93 taurus, v-6 with trouble codes that were scanned at auto
> zone.. the codes are 25, knock sensor
> 34 EVP(EGR Valve position)voltage out of range
> 51 ECT (Engine Coolant Temperature) sensor
> signal voltage too high
>
> the check engine light would come on an go off all the time.......
> start car and drive off and about a block away and it would come on..
> then go off and back on and then stay on.... i learned that the Taruus
> GL that i have does not have a Knock sensor so i ruled out the code 25
> as being the culprit... i then checked looked at the ECT and did not
> knwo how to check it so i went to the EVP and did not know how to check
> it.. i then went to the air filter and it looked brand new.. remembered
> that i changed it about one month ago... i then removed the MAF sensor
> and cleaned the two little wires/sensors in there with some windex on
> Q-tips and scratched up the electical connection on it to make sure it
> was making good contact to the harness... put it back in and drove
> around and the car seemed to run alot better. before it was killing when
> starting up and seems to have a shake in the engine like when you have a
> car thats flooding with the old carbs. so far two days now and the
> check engine light did not return.... could this be the fix for this
> car??? three other codes and noting mentioned about the MAF, but
> cleaning it corrected the problem... or did it????? thenks for a > reply...
> well i found out that the ck eng. light came back on.. i checked the ECT
> by putting the ohm meter on it when the engine was cold and then when
> warm and it seemed to be OK... nothing when cold and movement on the
> needle when hot.... then took out the EVP and brought it to auto zone
> and they put pressure on the valve and cheed it with the meter after
> putting six volts on it and they told me it was OK... i later returned
> home and pulled off the EGR and blew into one side and it was closed(no
> air flow from 1/2 pipe hole)... i then put vacuum on the egr and the
> valve was now open.. it seemed to be OK... i checked the small hose on
> the EVP and it seemed to be alright, no blocked.. the passage that the
> EVP small tube that went to the exhaut manifold seemed to not be
> blocked.. the tubing from the EGR seemed to be clear also...
> any suggestions????? one more question: when is the vacuum line to
> the EGR valve suppose to have vacuum to it???? i think the vacuum is
> whats suppose to open the EGR valve.. if i remmber correctly the intake
> manifold should be high in vacuum when at idle, then go off when you
> give it gas, and then come back on when the car is coasting along??? at
> least that is the way it was back in the old days of the vacuum operated
> windshield wipers... any suggestions???? thanks for a reply.....