86 LXi Auto Very high idle

[sfcmikej]

Hey guys

As usual I am here hoping you can help me out. My LXi is behaving badly with the transmission making a knocking sound and the car not having any acceleration or power when it does. This is not a real hard mechanical knock. More along the lines of a softer sputtering sound. Not sure if it is the tranny of some component of timing/fuel. When it happens it stops if you take the load off the engine. In order to make this as difficult as possible it is not happening all the time.

Today my daughter calls on the way to work saying it is doing it again. She pulls over turns the car off and then restarts it. Now the idle RPM is through the roof. About 3000+ or so. She managed to get the last mile or so to work but when I went over as soon as it starts the RPMs go high. Tried tapping/slapping the accelerator to get it down but it was a no go.

So the question I have is what to look for when I go back in the morning.

Thanks in advance for the help

Mike Johnston
86 LXi - Automatic

[ShyBoyCA6]

ok the only thing i came up with either you have vac leaks or a unpluged hose and for the knocking you sir have rod knock try doing a tune up and check your hoses for air leaks...if i knew which hose number is doing this i would let you know but i havent encounter a problem since im always working on the car since she is a 21 year old car

[sfcmikej]

Thanks shyboy88. So far that is whatis in my mind to look at. Hopefully someo ne has experienced this situation and I might get lucky and get more specific places to look.

Mike

[w261w261]

Probably should at least make sure that the throttle cable is not sticking. It comes out of the firewall and goes from the driver's side towards the passenger side in front of the box that says "PGI FM 12 Valve." A little further you'll see a spring-loaded wheel a couple of inches in diameter that the cable attaches to. It has a little thing on the top that you can see move when the throttle moves. It should be straight up at idle. I know I would be nervous standing in front of a car at 3k rpm, but maybe put on the emergency brake and have someone stand on the regular brake, then start it up and check for the throttle sticking open. If so, take the cable off the wheel and the mount by the "PGM" box, hold it up and dribble some oil down it. There are those that say that this is a temporary measure, because the additional oil will only attract more grit and cause it to stick again, but I've never noticed this.

[sfcmikej]

OK Thanks for the help guys.

I have looked at the throttle sticking and I think that is the problem. Some lube on the cable helped some but did not completely fix it.

I can manually push the throttle lever back to where it should be and the idle goes back to normal. It seems that the return coil spring on the throttle is a bit weak. Is that possible? With the throttle at low the spring is actually loose to the touch. At 3-4000 rpm it is not really that tight. Is it possible that the spring is the issue here? I don't know what would be considered normal. Is it possible to replace the spring and if so how difficult would that be? Is there someplace on the throttle body that could use some lubrication?

Thanks again for all the advice.

Mike

[w261w261]

The process of lubing a cable takes awhile sometimes. I would tie off the top so that the oil flows downhill pretty well, and I would use a thin oil. Put some in there, let it go for a few minutes, and repeat the process over a couple of hours. It's possible that your cable is rusted in some part, and your original lube job didn't go all the way down.

As far as the spring goes, I would think it would be simple to replace, but I haven't heard of our cars needing it. Hopefully, the Honda dealer will be able to get one for you.

I think your cable is still binding. Have someone sit in the car and work the accelerator with the cable disconnected. You play the part of the spring and see how much resistance you get.

[sfcmikej]

Thanks W261. That will be tomorrow's chore. Nasty weather here today.

Mike

[Bluntman]

I would spray some lube on that spring also, it worked for me.

[w261w261]

I should probably mention that there is a potential safety issue with a sticking throttle, particularly if your daughter (or a non-car person) is driving it. Let's say she gives the car a jab on the gas to accelerate, and the throttle sticks not at 3k rpm, but 5k. Now she's panicked and the car is going out of control. This happened to my son in his Subaru SVX, which has 240hp and can haul ass pretty well if you punch it. The throttle cable there goes through two right angle bends on its way, and it had started to fray and the broken wires got stuck with the throttle wide open. My son kicked it and it came loose, but it was too close.

In that case I had to replace the cable. In your case just make sure it works freely, and without trying to frighten your daughter, make sure she understands that she should just shift to neutral if something should happen. All this fuss about the recall of the Toyota floor mats and the cars "running away," when all the people had to do was grab the shifter and push it into neutral. I guess it's something people don't think of in the panic of the moment, but if they have spoken of it before, they'll probably remember.

In any case, it's not as bad as leaving a soda can in front of the driver's seat, and have it roll forward and lodge under the brake pedal.