1992 Mitsubishi Galant, 2 liter, SOHC, auto transmission, 130K miles

Hello and thanks for your ideas. The check engine light came on about a year ago and the diagnostic code that came up was 14 - Throttle Positon Sensor. After some adjusting, the light went off and all was pretty good (there was some idle surging when the engine was cold at times) until a few days ago, when the car suddelnly was very hard to start when cold - and the check engine light came on again. By depressing the accelerator, it finally did start after 3-4 short tries, and, once warmed up, the car ran fine. But the next morning the same hard-starting problem occurrred. I read the Diagnostic code again and this time it was 15 - the "Idle speed control (ISC) motor position sensor fault". I wonder if this is really the problem?? After shopping aroound, it seems this part is hard to find for this year (?) and VERY expensive. If the Idle Speed Control just increases the idle under certain conditions (i.e., when cold, or A/C is running, etc.), could I just unplug the ISC and speed up the idle a bit manually and get by (actually I tried this, but the car is still very hard to get started and keep going until it is a bit warmed up)? Since these cars are not worth a whole lot, I hate to spend a lot for a part that may not fix my problem......thanks a lot!!!

Adjusting the TPS wont correct a problem when yu get one. Lots of people think adjusting the TPS will magically fix the issue when it should be replaced. Thus changing the correct desired TPS position , depending if its alot of a little changes and alters many driving conditions , especially with an auto transmission. If the TPS is adjusted up a few degrees than wut its spossed to at cold idle , the computer will read that the throttle is opened a bit to which it will not need the aide of the IACV (idle air control valve) and also maing the fuel injectors spray an additional amount of fuel because of the read throttle signal. Which works against this case because the the throttle is infact not open to any extra degree as being read frum the TPS, so yur getting more fuel than needed on start up , and since its reading teh throttle is slightlly open it isnt correctly opening the IACV , which will cause idle surge when it does start and the TPS reads open , and then it decides to open the IACV because of the rpm read.

Thus this will make the IACV over operate , and most times not operate when it needs to when the a/c is on and slowing to a stop etc. It can be the issue now but originally wasnt. That tps is on many models which if yu could have taken a trip to a salvage lot and taken one off another Mitsubishi and put it on yur car.

ive had similar problems on my eclipse, turned out the problem was the mass-airflow sensor. worth a look, a new one is only like 30 bucks. by 'new' i mean a used one... one other than the one you are currently using. yea.

Yeah MAF is a sure candidate. Its simple in ways to tell , if yu have , well yur transmission shifts early , no matter how hard yu are pressing the accelerator , or does not readily select a lower gear when giving it a very good press on teh throttle , most likely the TPS is playing out alot.

Check your ECU!

Mine had the same issue. I had it rebuilt & all is well.

(It was leaky capacitors that were causing my issue.)

-Shawn