I have seen a few posts with similar problem,never resolved. The car will start and idle. If you step on gas it dies. If you feather on and off gas it will rev but stall if you let off. This is a 98 accord 2.3 I have changed egr,cat,O2 cleaned throtle body and intake and the only code I get is P0135 (o2 heater). The car acts the same hot or cold. Any ideas

 

I should add the car will also kind of rev up and down if you hold at about 1200 rpm it will go to 2300 and drop back to 1200 and back up over and over but will not go any higher. If I step on gas more it just dies

 

Suggest checking spark plug wires for spark leakage by spraying w/ fine water mist at night. If any sparks appear, then new wires are in order.

If plugs are over 50K miles, suggest replacing them. If they're relatively new, check for good spark w/ timing light lead attached to spark plug lead. If you're missing any flashes, the spark plug is not firing. Try this check w/ car in gear and parking brake set to create load w/ light throttle.

good luck

 

If the above checks out, I would then inspect/test/clean the IAC and FITV.

 

Thanks guys but no go. Replaced plugs and checked wires. I am unable to put car under load as it will die. I did replace alternator awhile ago because all the diodes in it fried not sure if it related. Its almost like spark turns on and off if throttle held at 1200. Engine goes up and down by itself . brooom broom broom brooom If I step on gas more it dies

 

Inspect distributor cap and rotor for cracks that could allow spark to leak to ground.

Cleaning IACV and throttle body may help idle, but may not affect ability to accelerate. Easy to do and worth a try.

You are sure there are no other codes but P0135?

Some drivability problems have been corrected by replacing forward O2 sensor. Since you don't have a code P0133, this is less likely to fix, but I have read of fixes that did not set a code, but were resolved w/ O2 sensor replacement. A replacement sensor can be purchased relatively inexpensively on ebay, auto parts, online sources. Denso sensor is avialable for <$50.

good luck

 

Replaced O2 yesterday but I believe car should run on preset parameters at idle when cold while the O2 heats up and it doesnt. Today I will spend some time on distributer. Wish me luck. There is no check engine light and the only code is po135

 

If you have access to a scanner, check temperature inputs such as air and coolant temperature. Errors in these inputs might cause too lean or rich operation. Also check long term fuel trim for trending high/low trim. If trim exceeds a preset value, Check Engine Light will be set.

Check PCV and PCV hose for damage, splits and working PCV. Make sure vacuum boost line is secure.

It could possibly be a weak coil that is breaking down under load. These usually are OK when cold and get worse as it warms up. This problem could arise when an internal short allows a weak spark that would break down (fail to ignite) under higher load. It might show up by checking coil secondary resistance. Something similar may be possible w/ the ignitor.

Tough problem. Problem like this takes great patience and perserverance.

good luck

 

Afew people have metioned IAC. If I put my finger in throttle I can feel it sucking air on top left. As I open throttle a little it stops sucking on top left. I am assuming thats what it should do. Also when I turn key forward I hear fuel pump come on but not shut off. Should fuel system pressurize and pump shut off ? This is when key on but engine not running. I changed cap and rotor today with no effect.

 

On earlier models the fuel pump would run until ECU disabled the Main Fuel Relay. At same time the Check Engine Light should go off. Fuel pump run is usually 2-3 secs. It has nothing to do w/ pressure level to my knowledge, and is a preset time.

The previous suggestions on checking scanned items and checking coil secondary resistance. The website techauto.awardspace.com has lots of info for checking coil and ignitor.

I agree IACV is working OK.

good luck