Fast Idle 1989 accord lx

[HondaGuy32]

Greetings all I posted a message in the performance section and got some answers to a few questions. Then a guy directed me to this section which I in my ignorance didn't see being that I am new to the board.

My problem is this, my 1989 honda accord lx with 165,000 miles on it, it's an automatic and carborated obviously since I'm here in this forum. It has recently started to idle up to 3500 rpm's. It does this only after the engine has warmed up. There are a few things that are wrong with the car really. The cruise control doesn't work not sure why on that yet. It hasn't worked since I bought it, I replaced the little control box with a new one and got a brand spanking new nice blue glowing light when I push the button but this is off topic.

In any case what are some problems that could be causing the high idle and what are some solutions to them. I already messed with the throttle knob turned it in both directions and it had no effect on the high idle. I have never changed my distributer caps since I bought it and there was alot of bad stuff in the car that I had to change after I bought it. How do you tell if a distributor cap is bad???

After I shut the engine off when it's warm the engine diesels as well. I figure that if I remedy the high idle it will lead me to the engine dieseling problem. Or at least get one fixed first.

I'm going to check the choke flap tonight, and investigate the throttle cable. Also does your engine dieseling damage your car in anyway I would think it would be hard on the camshaft. I also have the entire shop manual downloaded from pauldesigns.
Best regards and thank you for any replies as I know this is a topic that comes up often and I have been reading all the threads I can find on it. If you need more information on my car to possibly figure out the problem just post here I will be checking this thread all day today about once an hour probably. As well as tomorrow if I dont get it fixed.

[A20A1]

Well with the engine idling at anything above 1,500 will casue it to diesel a little.

You most likely poped a vacuum line on the idle diaphragm.

The idle diaphragm on the right side needs vacuum in order to pull the idle screw off the throttle, and lower the idle speed.
You could turn the srew all the way out as a temporary fix, untill you find the vacuum leak.


You should also check the throttle stop screw at the back of the carb and accelerator cable to make sure they aren't causing the problem.

[HondaGuy32]

The car diesels even when the rpm's are below 1000 right now but it could still be that the idle is too high. I noticed today when I was driving it that there is alot of hesitation when I push on the gas it putters around I have changed both the fuel filters so I know that is out of the question.

Vacuum lines vacuum lines EYE yi yi there's so many of them, what do you think is the best approach to checking them for leaks??

[mindlos]

I have never tried this but the guys on the forum say if you spray carb cleaner on your vacuum lines in a controlled manner and the rpms rise then that area you sprayed is the problem. Make sure the engine is not sucking in any splatter cause that will give you a false reading.

[HondaGuy32]

Hahah reading around here I see that carborator cleaner is a remedy for everything. hehe got a little problem with this here hmm spray it with carb cleaner I'll give it a try though hopefully it makes things easier.

[HondaGuy32]

This also started the same day I changed the oil, I spilled a little but no more then usual. I did do one thing different I added an oil additive.

[DanG86LX]

Forget oil spill. What started, high idle or dieseling?
You damn right about carb cleaner, take a can and dump it around carb. Spray and listen..

Well, idle is high cuz something is pulling ur throttle open:
- check cable
- choke flap position, vertical when engine warm. if not it may hold high idle cam engaged.
- throttle controller as A20A1 suggested, right side of carb "K" and "E", look here. This is a little tricky, depends on what you got on the car..
- A/C idle boost diaphragm (if u got A/C), Left side of carb "J" and "F".

So what is it?

[HondaGuy32]

I think the dieseling is caused by the high idle, I unscrewed the distributor and turned it a bit to lower the high idle. I think it messed with the timing. I don't think this is a remedy for the problem I think it might just cover it up.

Today is a colder day and when I shut the car off it didn't diesel which I found to be odd. It only idles high after it is hot I shut it off and then it diesels and I restart and blam it's high but before I messed with the distributor it was high all the time. Right now my prime suspect is the vacuum hose on the dashpot on the throttle bracket. This problem happens in the warm weather after the car is warm so this problem fits but I could be wrong even still.

I'll fill you in on more information when I get home, I'll check out everything you listed DanG86lx and then post later tonight as well.

[HondaGuy32]

The wierdest damn thing happened yesterday. It just stopped dieseling and the high idle is gone. I didn't know cars could fix themselves but evidently they can. I think that it is because the temperature outside is cooler then if it starts to do it when it's warm again it definetly has to do with heat.

However I have noticed there is alot of hesitation in between gears and it is lacking in power now. I have to put the peddle to the floor to get it to go. I think I have the idle turned down too low. It almost dies but doesn't get close enough when I'm sitting somewhere.

Also when I am sitting in gear it tries to pull me forward the engine kind jolts around like the entire spine of the car is being shaken. I have never adjusted my valves so I was thinking that could have something to do with it.

[A20A1]

I think your timing is too far off now. But it could be the valves as well.

But thats most likely why you lost power, is cause you adjusted the timing. The lowered timing is also why the idle dropped... and the reason you have a hard time maintaining idle.

I get the rocking motion now and then but thats cause my ignition isn't working its best right now. I used to think it was the valves.. but I adjusted them twice and it didn't go away.
It still could be the valves though cause I did mess up once the first time I ever adjusted valves on my first engine and that cause rocking.

But anyways, did you check for vacuum leaks?

[A20A1]

If / When you find and or fix the vacuum leak I suggest you start from scratch when adjusting the idle and timing.

warm the car up
Set the ignition timing back to TOP DEAD CENTER with the ignition advance hose(s) unplugged.

Plug the advance hose(s) back in then set throttle stop screw to recommended idle when in neutral.
(Without a/c, fans, or headlights on)

Put the car in gear and reset the idle with the idle screw on the left side of the carb.

Turn on A/C fans and Headlights and reset the idle with the idle screw on the right side of the carb.

actually before setting the 3 idle screws it's best to turn them all out except for the throttle stop screw. That way the idle is held / controlled by the throttle stop screw only and you won't end up with a bad adjustment.

[HondaGuy32]

I plan on doing exactly what you say Michael(don't forget the carborator cleaner aye) right now the car idles very steadily unless I'm in drive. If I'm in drive for some reason when I stop at a stop light the car is fine for a few seconds but then tries to pull me forward to me it seems like the car is about to die. With all the little things wrong with it now I'm considering a tune-up since I'm giving the car to my girlfriend and buying a 1998 Honda Accord but I would like to try and fix all that I can on the 89