Hello,

I have a 2002 Accord, Vtec 4cyl. The base idle screw on the throttle body will not turn and the slot in the screw is a somewhat stripped and bound to get worse.

Does anyone have a technique on getting that screw to loosen up? As I understand it, they put locktite or something similar on the screw at the factory. Can I apply heat? Has anyone ever drilled out one of these screws? If I go that route, does anyone have a screw they could sell? I've got a very low base idle and turning that screw will be the starting point for troubleshooting. Thank you.

 

First the screw never needs to be adjusted unless someone already deliberately messed with it.

Second you may be trying to turn the wrong screw. There shouldn't be any loctite on it.

 

Yup.

Why are you trying to adjust the idle via the screw?
If the TB is coked up this can choke the idle too low, if the IACV is coked up it may not allow enough air bypass to maintain correct idle under load. General tune of the engine, worn plugs/wires/incorrect plug gap/etc.

On unmodified FI cars one normally never goes near the idle screw.

 

Car idles at about 275 RPM without AC. Turn on the AC and the idle is around 800. Start the car without a foot on the gas and idle is 1100. Turn off the AC and jab the throttle and the idle drops to 275. Cleaned the throttle body and IACV real well about a year ago and replaced the TPS. Wanted to go at it again and check base idle but can't turn the screw. Will probably remove the throttle body again this weekend and look it all over and do some more testing.

 

Have you verified the basics? Base ignition timing, base cam timing, compression, ignition components quality, etc?

 

Take a picture of your idle adjust screw.

The car is designed to idle higher on a cold start at around 1500 rpms and will gradually drop down to 750.

 

The idle screw was definitely turned all the way in or almost so and it did look like there was some type of locking compound on it. I managed to loosen it and get it turning with a small screwdriver and hammer. I took the screw out and cleaned up the slot with a Dremel. Put it back in and was able to get a good adjustment on the base idle. I bought the car as a certified used Honda at a Honda dealer so I don't think it is likely the screw was ever moved since the car left the factory. I cleaned the throttle body and put a new air filter in and the car idles great now.

 

The FITV/IACV/TB Cleaning thread probably wouldn't be too bad to go through.