Hello,

So a new problem, well... a problem that my car has always experienced is that, when parked for 20 secs - 1 min, the rpm begins to fall and rise sharply from 1-2 and vice-versa constantly all while parked.

This has happened before WHILE driving, but my coolant was low and I addressed the issue on the spot, and was fixed. This issue is only when the car is parked...

Is this a coolant issue? What other issue could this be? I have a brand new car battery, and a new starter.

Regards!

 

Hello,

I did some research and everything points to the sensor fault. Is this a good place to start checking?

 

You are having the coolant temprature sensor checked...Yes?

 

It should look about like this Image below.. click image for bigger picture.
WheelBrokerAng

 

1987 LX has a carburator, so it probably doesn't have THAT sensor.

Or is it an LXi ??

Better yet, WHAT sensor did you mean in the second post?

 

So my coolant temperature sensor should look like that? If it doesn't what would it look like? I need to find where it is, but I'll definetly check that.

My Honda 1987 LXI is a fuel injector.

 

The surging idle can be caused by air in the cooling system. There's a little air-bleed bolt in the thermostat housing (#22 in the picture). Open it a bit & see if air comes out.


I looked around the parts drawings for 87 LXi and I didn't find the temperature sensor. I hope someone chimes in who knows...

 

From the shop manual you can download from the online manuals thread in the DIY section, there is a sensor in the radiator.

Also look to see how to properly bleed air from the system when refilling coolant. That could also be your problem.

 

if it is a LXI could be the inner valve in the fast idle valve that is loose,,,,,,,,remove 1 screw and loosen the other, flip the top cover to the side get a flat tip screwdriver and tighten the inner valve till it bottoms ...DO NOT OVER TIGHTEN IT ..

 

The part near #25 could also be clogged. It controls idle via the antifreeze temp in the engine. Remove and clean screen and replace. You also just have air in your system or a small leak in one of the your hoses or radiator. Honda's are known for the hunting idle issues especially when there a problem with the coolant.