Got an 89 Honda accord lx. When I start The car it idles rough at 1. to 1.5 rpm then it slowly goes up to 3 to 3.5 rpms and stays there, will not cut back after being warmed up. Also if i kick off the choke before temp gauge rises i have Min. heat, if i let it run till temp gauge is showing warm I have awesome heat. The temp gauge will go way done while running and when I stop it goes back up to normal and I have awesome heat again.

 

You need a new thermostat to control warmup and stablize temperature.

Choke may need cleaning/lubricating to avoid sticking.

good luck

 

Nice.....a 3rd gen

Just me but sounds like it could be two different issues. I'd start with getting a new thermostat. Be sure to properly bleed the air out of the system when you replace it.

Run the car for a few days and see if the temp settles out.

After that, if you are still getting the high idle (~3K). You are going to have to start checking the "fast idle unloader". Don't really want to get into all of the details of that right now.....gets confusing ....but in the end it is really simple, trust me I've had/have serveral 3rd gen's in both carb and FI trims. I've delt with the unloader on several of the carb'd ones I've had.

EDIT: Slow typing....I see TX posted while I was typing

 

changed out thermostat and have constant good heat will run for a few days and then will see if carb changed any, thanks for the advise fellows
John

 

Sounds good....thanks for the update.

If the high/hanging idle comes back let us know. IMHO, 90% of the time this is the thermo valve/ported vac switch on the back side of the block on the right/drivers side.

Of course a good cleaning of the carb with carb cleaner never hurts anything - top of the air cleaner off, remove the little screen over the throat of the carb - two nuts that take a 10mm socket, just don't drop them into the carb - Give it a good spray, use a finger to open the butterflys and get both sides of them and down into the throat of the carb.

 

Well finally found a ported vac switch and replaced the old one, nothing has changed, one thing that I have noticed is I got about 100 miles out of a full tank of gas, heat is good but still have the other problems, can you help me out some more, by the way cleaned the carb several times with cleaner, that didn't help either, thanks

 

Really should have tested the PVS - it is a three way valve that opens different posts (vac) at different temps.

Does this "high idle" always happen or is it a once in a while thing.

Is the upper butterfly on the carb opening all the way when warm.

 

It does it everytime I start the hot rod, also I am not sure about PVS you mentioned in last message and yes the butterfly does work

 

PVS - ported vac switch

 

Ok....sorry for being slow but I'm now guessing the car has been doing this since you got it and not something that has just started happening?

While it is running and the upper butterfly is open - are you seeing gas drops going down the throat of the carb? Are all of the vac lines connected - I know there is only like two miles of them on this thing.

Next, when the engine is cold - not ran for a few hours. Test the resistance on the ECT sensor - two wire sensor on the back side of the block.

Sorry it is not a whole lot of fun on these OBD-O systems to figure things out....you get no codes and have to know the 20 different things that might be "off" and are giving the ECU a wrong reading.

PVS = Ported Vac Switch. One of the PVC's for the fast idle unloader is on the back side of the block - engine to firewall, under the intake manifold