just picked up an 88 accord lx for the kid.. runs great, looks goood etc etc.. starts fine, idles on choke, kicks down to about 12-1300 rpms, and runs great.. until the water temp gets into the normal operating area.. then it surges between 700 and about 1600 rpm, only at idle.. and pretty continuously..

I've changed the PCV valve, fuel filter, flushed the radiator, checked the (thousands of) vacuum lines, cleaned the little selenoid on the back of the carb and made sure it's grounded, sea foamed and B12'd the carb..

any ideas where I should go next?

Thanks in advance

 

This is the single carb setup on the 2.0, right?

There should be an idle compensator solenoid if the car is equipped with A/C that kicks up the idle slightly when the a/c is turned on, and also provides a fast idle when the vehicle is started cold. If the solenoid is erratic, it can cause a surging idle speed. I think it's vacuum signalled -- been a long time since I worked on one of these. Find the solenoid with the plunger near the throttle linkage, it should have a vacuum hose going to it, or possibly a wiring harness connector. If it's vacuum, check the hoses for cracks or rotting. If it's electrical, clean all the connections, and retry.

Also, go over the rest of your vacuum hoses with B-12 and look for leaks, even the ones you've checked, as a surging idle is often caused by a vacuum leak, especially when warm. Pay particular attention to the intake area.

 

That idle is a little bit high, be sure there is just a little slack in the throttle cable.
The idle adjustment is a black **** on the back passenger side of the carb, but it has a slot inside it so you can use a small screwdriver. under 1000 RPM is close

You can take off the breather and plug the vacum lines on the passenger side of the carb, the one on the drivers side is a vent so don't plug it.
Now that you can see something, you can look thru the little window on the drivers side of the carb to see the gas level; should be visable in the glass port.
Next thing to check is the choke pull off diaphram located on the top front passenger side of the carb, it has 2 vacum lines going to it and a rod going to the choke plate linkage.Under any conditions, with the engine running,if you pinch off those 2 vacum lines the choke plate should pull open.
Now look to the passenger side of the carb and you will see a small lever with a phillips head screw that pushes a lever on the lower throttle plate. back that screw off so that it is not opening the throttle plate.
That is a throttle let down system that is not worth the effort of using ! LOL

Another couple places for vacum leaks, the hot air door diaphram on the breather snorkle, and the vacumadvance diaphrams on theDist.

 

Yep, single carb on a 2.0 I believe.. I did pull that idle compensator off the back of the carb, cleaned it, checked the wiring.. I'll put a MM on the wiring and check for continuity, and make sure it's plunging with a jumper tho.

I'll bring that idle down a bit, and back that throttle plate adjustment out.. think I might've been adjusting the idle with that throttle plate screw :P


I did check the diaphram on the hot air door, seems ok.. guess I'll just keep testing out the rest of the diaphrams and vacuum lines.. frustration got the best of me so I took the week off from piddling with it, but the kid's getting his liscense in a coupla weeks.. suppose I should get back on this project heh

thanks for the tips, I'll keep you posted!