driveHonda757

Hello Honda Tech I am new to the forums here but not new to the honda game in any way..

I have a 97 hatch with a b16a2 from a 99 si, running a p2t ecu

Recently I decided to run seafoam thru my motor using an atomizer machine, (I work at a shop and have ran this service on many vehicles and have had good results, either way I was skeptical using this on my vehicle but decided to do it anyway)

I have an issue with the idle now, I have checked alot of things on it and as of now it will run fine when the weather is warm, when the weather is colder out and I have any load on the engine (ie headlights, ac, heat running) the idle will jump to around 1200 and if I sit at a traffic light it will raise up to 1500 rpms and throw a p0505 code.

What I have replaced so far and checked...

Tps sensor threw a code so it was replaced and re calibrated
Iacv has been changed 4 times with no luck
tested all iacv so the click and have ohms tested them and extensively cleaned
Have adjusted the idle screw
Checked all Vacuum lines and have looked for leaks at the
throttle body gasket and intake manifold gasket
Bleed the coolant system about 15 times
checked and sanded all the engine bay grounds
cleaned the throttle body vigorously
checked temperature and ohms on ect
replaced spark plugs and wires
new rotor and cap and fuel filter
voltage at alternator and battery tests


Have not checked...yet

Map sensor (no code thrown not sure how to test it)
ignition timing
fuel pressure

anyway if anybody can point me in the right direction it would be greatly appreciated, I can not figure out for the life of me why my car will not idle and I cannot trust it for daily driving, when the p0505 is thrown it is difficult to take off at traffic lights due to hesitation, as well as shuddering when pressing the throttle down or letting off.

I understand this topic has been covered a million times here and on other sites but I am really stumped here.

Alpha Q

I know you said you tested the alternator but swap it out with a new one.
just because it test good don't always mean its good..

I had same problem, tested and replaced everything... ended up being the alternator..

Tested it when its cold and you have your headlights, ac, or heat running..

This is typical of an alternator on its way out....

jbpnoman

Have you reset the ECU to verify the code comes back? An alternator wouldn't throw P0505. Have you checked the coolant lines running to and from the IACV? I assume since you bled the system, you've also checked the levels.

Check out this thread.

driveHonda757

Yeah I have double checked the level and the lines also checked to
Make sure that the throttle blade is fully sealed which it it and the idle stop screw has not been messed with because the yellow paint is still intact I have noticed that at about 20 to 30 percent throttle there is a whistling sound Coming from the intake which occurred after adjusting the idle screw