Engine light comes on when i open up throttle

4.0L
what transmission, mines a 5 speed stick so?????
idles good, well that dont take much.
will only move, car moves?
with what wide open ,the throttle?
well just barely throttle is normal, why say that?

my guess is car has low power, or can not go fast in all gears.
is that it?
if yes, that is transmission slip or a weak engine,
transmission slip is easy RPM goes way high car dont move
weak engine acts like brakes stuck on , low RPM deep right foot.
post all symptoms and win, big time.

Start with 1 full turn out from the closed position on both the idle and high speed mixture screws. After the engine has warmed up, hold the throttle wide open and adjust the high speed mixture screw until the engine runs at the highest RPM then turn the screw counter-clockwise about 1/8 turn.
Next, turn the low speed mixture screw in whichever position gives the best idle.
After making these adjustments, check the throttle response. If the engine hesitates when applying the throttle, turn the low speed mixture screw counter-clockwise about 1/8 turn.

if the engine is in good shape..screw in both carb jets adjusting screws till they seat lightly, then back them out 1 1/2 turns, srew in the throttle adj screw a turn and start the motor,,warning if the chain is on make sure the blade isnt likely to touch anything when the engine starts as you will have to have the brake off to get started and adjusted. With the engine running, adjust the throttle srew until it is idling just above shutting off speed, then adjust the "L" low speed jet to get the best idling speed without srewing it in much, reset the throttle srew, then , while trying to accelerate suddenly each time, open the Low jet a little at a time until the machine accelerates smoothly without hesitation. Reset the throttle srew to a position that the chain stops running at idle and check again that the acceleration is without hesitation ( usually with "L" jet about 1/4 turn out more than best idling). The high "H" jet can now be set to give the best power while cutting a block of wood.

To start with, you have a throttle body instead of a carburetor.
On that throttle body is a component called an air control valve.
That valve is how the computer controls the idle speed. It should open and close the air flow into the intake manifold as needed.
Is the check engine light on when you are driving ? Have you checked the fuel pressure ?

There are two needle screws that can be adjusted to make the engine run properly. Be certain that the carburetor is clean and the diaphragm is in good condition, and the fuel is new. The two needle screws mentioned above should initially be adjusted at one turn open from turned in all the way (lightly seated). Each of these needle screws performs different functions. One is for idle and throttle response (this screw is marked "L" and the other screw is marked "H". L and H are marked on the carburetor body and also on the plastic "shroud" near the adjustment screws. These screws are not interchangeable, being foolproof since the thread sizes are not the same. When properly adjusted the low speed screw (L) allows the engine to idle properly and throttle response will work properly. When the high speed screw is adjusted properly the engine will have correct power at full speed. Adjust the low speed screw so that the engine idles and when you squeeze throttle all the way to wide open the engine should not hesitate and should come up to full speed and when you drop the throttle it should idle nicely without stalling. Now adjust the high speed screw. Hold throttle wide open, holding it there while you adjust the high speed screw. If this scares you (be carefully so that the spinning chain does not cut you!) you may adjust the high speed screw at idle, turning it just slightly in or out. The high speed screw should be adjusted so that the engine does not run clean at wide open throttle but sputters slightly, slightly adjusted open from running clean to slightly sputtering. When under load (cutting a log) the engine should run clean. Good luck!

white smoke out of the exhaust would be a sign that it is burning coolant... if it goes away after it warms up, it could just be condensation inside the exhaust pipe. 1800 rpm is a very high idle, maybe have your IAC motor on the throttle body checked... check engine light? if so have the code read at your local auto zone.

When you clean the MAS you should use no residue electrical cleaner - some solvent 'cleaners' leave a residue which affects the MAS operation. Two other areas to check are the IAC Idle Air Control valve on the throttle body. The ECU opens the IAC when the throttle is closed, at idle, and allows a measured volume of air to pass the throttle and thereby ensure an even running engine. Generally if the IAC is at fault the symptom is that if you put load on the engine at idle, such as engage the power steering, the engine speed dies away or stops. Just take the IAC off and clean it with Carb. or brake solvent cleaner and a cloth. Working in conjunction with the IAC is the TPS (throttle position sensor) which is a variable potentiometer that measures the throttle shaft rotation usually located on the throttle body opposite the accelerator to throttle spring loaded cam. There three electrical contacts: on one side it is at 0 to 0.48volts; the other side is 5 volts: and the middle one is the centre contact arm. When the throttle turns the contact arm sweeps in an arc from the 0 volts end towards the 5 volts end sending a voltage that the ECU interprets as throttle position. If the IAC clean up does not work and the TPS is OK then have a look at the EGR (exhaust gas recirculation) valve. If this valve fails open or the exhaust gas feeder tube is blocked the engine runs hot and is very hesitant with misfiring

You will have to get a service tech to attach a scanner and read the trouble codes. They should be stored in the computer memory. It should give you a starting place to diagnose the problem.

Here is the cause of surges, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

yes, this is the case of a failed throttle body, in which case it needs replaced, the car is getting too much fuel causing the high idle. this needs replaced asap. you could proably find a small independant honda shop that could do the work for less.