G$

Recently, I have been experiencing problems with my RPM being too high. When I first start the car, it will idle @ 3 grand and then eventually work its way down to 1500rpm. On the highway, I am redlining @ 65. Needless to say, gas mileage is shitty right now. It is all interelated. The rpm's on the car are just dialed up for some reason. I first suspected a vacum leak somewhere but can't find that. I disconnected the battery for a few hours hoping it might clear a bad code or something. I checked the ECU codes but it isn't throwing any. Any suggestions would be greatly appreciated!!! Thanks!
G$

92CivicSiR

kahren

check your throttle cable/TB

HXMan

Check your idle setting, plus check your IACV.

Is your car an auto? That is the only way you could be redlined at 65mph....no matter what your Idle is at if you are in 5th gear, clutch out, at 65 you will not be at redline. Not possible.

G$

I wish it weren't possibly, BUT, that IS what is happening. It is a 1988 CRX Si.
G$

G$

What should I be checking my throttle cable for? WHere is the throttle cable and what is TB? Thanks
G$

Gasoline Fumes

Either your clutch is slipping, or your tachometer is wrong.

d0nkeyxPunch

I used to have the same kind of problem when I got headwork, higher compression pistons, and CTR cams. Try getting your distribution timing corrected. That was the problem with mine and after that, it idled at stock. I'm pretty sure that its your distribution timing.

G$

Any idea what would have caused this? It used to do it intermittently. Now it does it constantly. The guy who posted earlier said its the clutch or tach. I know it isn't the clutch because it does it at idle as well. I know the tach is right because I can hear it rapping out. THanks
G$

88_SC_CRX_Si

Do like mentioned above and check your idle. On my 88 Si the idle air screw has a bad habit of backing it's self out, thus raising the idle speed. Get yourself a Helms Manual ASAP. This will give you help in locating where all this stuff is in the future.

In the mean time, the Throttle Body is where the big black hose connects to the engine from the intake box, on the right hand side of the engine bay. Look right above that on the TB, and you will see a brass colored T slot head in a inset hole. Thats you idle air srew adjument. Next look on the side of the TB closest to the fire wall, and you will see a round cylinder looking thing with a connector, and some wires going to it. This is your EACV/IAC sensor, and it needs to be unplugged after the engine has reached operating temp, and the cooling fans have kicked on at least once. When you disconnect the EACV/IAC the computer will throw an error code so just ignore it. Adjust the idle air screw by either turning it in to slow the idle down, or out to speeed it up. Check you Tach and set the idle to around 750 rpm.

Next, kill the engine and plug the connector to the EACV/IAC back in again. Then disconnect the battery for 30+ seconds , this will erase the error you got when you disconnected the EACV/IAC. Let it run for 5+ minutes without giving it gas so the ECU can learn the new setting.

G$

Excellent! I will try this ASAP! Thanks for your help!!!
G$ <U></U>

G$

Well, I tried it but to no avail. The screw is as far in as it can go. It can't go in any tighter and the damn thing STILL idles at 1500 rpm. I have NO idea what the deal is here. Talk about frustrating! Its about time for a !!! I will go get one of those manuals you speak of. Until then, please feel free to drop any more possible suggestions you may have. Thanks for all of your help! I really appreciate it.
G$

walker111

your fast idle sensor might be bad i had the same problem in my 90 teg

G$

Hey HH111, Thanks for your post. Was your problem IDENTICAL to mine? If so, I bet you may be right! I hate to throw parts at something but if you had EXACTLY the same problem, it might be worth a try.
G$

walker111

same exact problem let me know how it turns out

G$

Im not able to find a "Fast Idle Sensor". Closest thing is a "Fast Idle Valve". Is this the animal you speak of? Thanks!
G$

Spade

Just out of Morbid curiosity, did you check the trottle cable? and attempt to loosen it?

G$

Nope. Not the throttle cable. I got to thinking earlier today, could it be the Ignitor? I used to have the dancing tach problem and then it just went away a few months ago. The car also used to just jump up 1500-3000 rpm for no apparent reason. For instance, I would be cruising at 40 mph and the tach would be reading 3000rpm then just all of a sudden, the thing would act like I downshifted or something and be revving @ around 5 grand. THen after a while, it would go back down to normal. Now, it just STAYS high.

whagkangmakulet

I have the same problem on my car which is 91 Honda Civic Si . I've been trying to fix it also. I have an identical car which is a 90 Si also and i've swapped almost every component within the throtle body such as Throtle control, Idle speed, Temp, EAC, map sensor, Injectors, adjust the idle screw, ECU..and adjust the timing! NO LUCK!! I thinks its the ignition system, but it's impossible due to some fuel control that is being applied during idle. My las resort is go to the dealership and have it check.. but i know it would be a grip of $$$ for them to check it.. PLS Help US...

Spade

I have a 97 EX, it will Idle sometime at 1500 and then drop to 750. Sometimes it stays at 1500 until I come to a complete stop then drops to 750, does anyone else have or have had this problem? Is it some screwy thing that EX's have or no? My 00 HX doesn't do this so I am wondering what it is. Any suggestions would be appreciated.

G$

Just found this info (this may not be it either but every little bit helps, right?):

As you may recall from a previous post, the car would randomly establish it's idle as low as 300 to 500 rpm--a wonder it didn't reoutinely stall. After sitting there for ten seconds or so, it wouldn't spontaneously rise above normal, and then settle back. Any small touch to the throttle would immediately cause the idle speed to pop back up.

I appreciate the suggestions from list members to change the plugs. I did that, and also the fuel filter, but without results.

As it turns out, these cars ('90 Civic Si) have a mechanical screw that determines how far the throttle close. It is hard to see, located underneath the place where the throttle shaft enters the throttle body. The screw is of a harder material than the part of the throttle assembly that rests on it. Over the years(our car has almost 170,000 miles on it) the metal part which rests on teh screw has worn, which allowed the throttle plates to close more than necessary.

The easy solution (if you have very flexible fingers) is just to tighten the throttle stop screw. Here is how to do it:

Remove the throttle cable--just undo the two bolts that hold the outer part of thecable to the front of the engine for enough slack. There is also a vacuum line you may want to remove to get more room. The throttle stop screw takes an alan wrench of 2.5mm. Get a short one--there is very little room. The screw is locked in place with a nut (I think it is 7 or 8mm). Again, a short wrench will help. You may findthat the screw and nut were painted at the factory to show that they were adjusted. This will be helpful.

Undo the nut a little bit and adjust the screw inward no morethen 1/8 turn. The paint marks should help you keep track. Lock it back down with the nut, being sure the screw does not turn in the process.

If you are clumsy, and/or want to do a more compete job, you can remove the throttle body itself. It comes off with 4 nuts, but you also must remove the air intake, two fuel-related hoses on the bottom, the electrical connector to what I think is the throttle position sensor, some wires that are held in place by a fixture on the throttle body, and a few vacuum line hoses. If your car is as well worn as ours, you will certainly find a lock of black stuff in and around the throttle plates--which probably contributes to blocking the air from getting through at idle. Gently clean it off with carb cleaner and wip away any residue. It is very easy to adjust the throttle stop with the throttle body off, but again, keep it to 1/8 turn, max.

BoostedED9

i have a similar problem but only the oposite, when i come to a complete stop it drops to like 900-1100rpm and then out of nowhere it drops down to like 500.. anyone had this problem before???

Spade

I have the problem currently on my 97 EX and am researching it.

G$

Damn! It sure seems like a LOT of people are having this problem! I can't believe NOBODY has had any experience in FIXING it!!! Surely SOMEBODY can help us all out here!!!

Spade

So the Idle is supposed to be at 1500 until I come to a complete stop? What the hell is that about?