check engine light

**galantlvr34** · 01-08-2011, 04:57 PM

i have a 1994 galant gs the check engine light will come on sometimes and when the car moves it will shut off.do you guys have any suggestions on what it might be.thanks.

**mygalantwasfree** · 01-09-2011, 01:59 AM

Originally Posted by galantlvr34

i have a 1994 galant gs the check engine light will come on sometimes and when the car moves it will shut off.do you guys have any suggestions on what it might be.thanks.

I'm guessing that yours is OBD I? My guess is, either you have a loose ground on the MIL lamp, or you have a sensor that is on the verge of going bad. That is, when your engine's RPM's are above idle speed, the sensor reports voltage readings within the normal threshold, but when you go back to idle, the voltage readings fall back outside of the normal threshold and your computer throws a MIL code. I could be wrong, but I don't believe that OBD I computers can "store" codes.

(The above is just my 2 cents. I could be wrong about it, that's what I'm guessing is happening.)

Can't you just complete the circuit under the dashboard at idle and read the code?

**galantlvr34** · 01-09-2011, 09:45 AM

Originally Posted by mygalantwasfree

I'm guessing that yours is OBD I? My guess is, either you have a loose ground on the MIL lamp, or you have a sensor that is on the verge of going bad. That is, when your engine's RPM's are above idle speed, the sensor reports voltage readings within the normal threshold, but when you go back to idle, the voltage readings fall back outside of the normal threshold and your computer throws a MIL code. I could be wrong, but I don't believe that OBD I computers can "store" codes.

(The above is just my 2 cents. I could be wrong about it, that's what I'm guessing is happening.)

Can't you just complete the circuit under the dashboard at idle and read the code?

it rarely comes on.if it comes on and if i reverse or go forward it goes off and doesnt come back on.just a little bit of moving it shuts off.i just changed the plugs and wires because it had a misfire.the misfire went away after the tune up.i also changed the pcv valve.

**Galanttuner10** · 01-09-2011, 10:05 AM

see if you can scan for the code, i know scanning an OBD1.5 car is a bitch but if you can get a code i have the 94 galant shop manual with all probable causes of whatever code it is.

**galantlvr34** · 01-09-2011, 10:07 AM

Originally Posted by Galanttuner10

see if you can scan for the code, i know scanning an OBD1.5 car is a bitch but if you can get a code i have the 94 galant shop manual with all probable causes of whatever code it is.

yeah it is kind of hard to do though because it doesnt come on all the time.

**Galanttuner10** · 01-09-2011, 10:30 AM

i understand, do you have a friend with a scanner as if you do, it comes on dont even move the car and have them come over and scan it.

other than the light flickering sometimes is the car acting weird at all?

**galantlvr34** · 01-09-2011, 10:34 AM

Originally Posted by Galanttuner10

i understand, do you have a friend with a scanner as if you do, it comes on dont even move the car and have them come over and scan it.

other than the light flickering sometimes is the car acting weird at all?

no i have to get a obd1 scanner.it doesnt really seem to be acting weird.what is the car suppose to idle at when it is not warmed up?

**Galanttuner10** · 01-09-2011, 10:40 AM

mine idles around 1200 when cold then around 800 warmed up, are you auto or 5 speed? just so i know.

**galantlvr34** · 01-09-2011, 10:42 AM

Originally Posted by Galanttuner10

mine idles around 1200 when cold then around 800 warmed up, are you auto or 5 speed? just so i know.

my car is 5 speed.when i first start it cold it idles around 1500 and when it is warmed up it idles at 1000

**Galanttuner10** · 01-09-2011, 10:56 AM

idles a little high but thats fine, if you cant to lower it there is a screw on the top of the throttle body towards the front of the car, turn that down when the car is warmed up to lower it a little if you want

**galantlvr34** · 01-09-2011, 11:03 AM

Originally Posted by Galanttuner10

idles a little high but thats fine, if you cant to lower it there is a screw on the top of the throttle body towards the front of the car, turn that down when the car is warmed up to lower it a little if you want

alright so its fine?i wanted to make sure the idle was alright so i know it isnt the idle air control valve.