Engine Performance problem
1991 Hyundai Excel 4 cyl Front Wheel Drive Automatic 79, xxx miles
I have a rough running Hyundai.
if I adjust the ide of the engine for when its in neutral, I have to hold the gas & brake when I put it in gear.
if I adjust it to idle in gear it is too fast when in neutral.
plus it has a hunting idle. Slightly up & down.
also oil light comes on when idling in gear unless I have engine idled up.
the car runs & drives perfect, once I take off frm a stoplight, it behaves fine.
this is my spare vehicle, & it recently started doing this.
I checked for vacuum leaks. I tried several different methods, 1 was water, 2 was " either" is small stages while engine was cold, I sprayed all connections, hoses, & possible leak places with no speed up nor slow down of engine.
I replaced the injector O-ring seals, but that didnt change anything.
money is tight, actually too tight, & I cant afford to replace parts unless they are bad, I checked on TPS & they are aprox $50 which is almost out of my budget, but I will juggle finances if so, but I dont want to replace it & not fix my car.
if it is or could be something else? Give me some insight. I was a mechanic in earlier days of fuel injection, & worked on american stuff then at a dealership, & changed careers, due to a bad boss. &Amp; not kept up to date as well as I should on " modern" cars, I switched careers in 1993.