ok, today my car start doing this thing,:
when its on idle, it revs up around 2000-2200rpm.
but its not like a normal idle, it sounds like im pressing on the gaz pedal to have it rev up to this rpm.
and when im in gear (1st-2nd-3rd) like on a small street, the car drives on its own, almost like if i was on cruise control.
could it be that the throttle cable is stuck somewhere, or could it be that i should adjust my idle.
i drove it thursday,friday with no problems at all, and even saturday morning too,
it kinda started to do it later in the day.

the car has no problems accelerating, with the exception of the 4000rpm stuttering when going normal cruising speed on the highway,

engine is a 1988 T2 ,hks air filter, racing beat FCD , corksport 80mm catback with downpipe, msd spark plug wires.

any hints would help, thanks in advance guys !!

 

Ya, the first thing i would do and check the throttle cable to see if its too tight. Check the cable play and make sure its in spec. It could be that the cable is too tight and its opening the plates at all times.

 

Also check the cruise control cable , if applicable

 

Get the TPS set spot on and adjust idle speed to 750. Then go back and verify the settings. Start with the simple stuff; it might be something really easy.

 

yes it has cruise control, ill look at it.

 

what do you mean the "TPS set spot on" ???

 

OK UPDATE....
i totally removed the cruise control unit, and the throttle body cable doesnt seem too tight ...
and it stills do it ... ill get a video tomorrow.

 

check things that have to do with the idle and acceleration, like timing mite have something to do with it( maybe too advance) like chuck said see if the tps is adjusted correctly, if that doesn't work you mite want to check the throttle body maybe take it off and clean it, see if the plates are stuck open not closing properly? just some suggestions

 

Just to clarify, is the idle steady at 2k+ rpm or does it bounce from 750 to 2k+?
If steady, check for a small vacuum leak. Especially around the intake manifold nipples. I knocked one off and it set my idle at ~2500 rpm. You can try spraying carb cleaner on intake components and see if they are leaking. If the engine speed increases, that's the problem area.

 

its not like it was on idle...
its really like if im pressing the gaz and it constantly revs up to 2000-2500rpm.

 

have you modded your throttlebody? when i removed all the smog crap off my last build i had left what i think mighta been the fast idle arm or some such thing on the throttle body because the screw holdin it stripped. a couple days later throttle would stick intermittantly as the arm was riding against the throttle plate shaft and holding it open. check your throttle plate shafts for shiny spots

 

where is that fast idle arm located ?? and shiny spots from where ???
and no i havent modded the throttle body. its still oem spec.