89 Accord Idle Problem

[twstice]

I have a 1989 Honda Accord SE-I 2.0 four cylinder fuel injected w/ auto transmission. it has 190k miles on it and runs fine until recently. I got in the car yesterday morning, start it, and it revs up to about 2,000 rpms(normal warm-up) but then it raises slowly up to 3,000 rpms and sits there. I finally put the car in gear and leave. It seems to be driving fine till i get a little ways down the road and let off the gas, it feels like the accelerator is stuck and its goin by itself, so i put the car in neutral and roll to a stop. It is idling ver erratic : from a normal idle, it revs way up 2,000 rpm and then stops and goes right back down to idle, then back up again, then down, etc. And it just keeps doing that. After reading all the threads that looked related to my problem, i narrowed it down to the Fast Idle Valve or the Throttle Position Sensor. I was almost positive it was the Fast Idle Valve because of the following symptoms : Starting at cold it would rev up to 2,000 rpm like normal but slowly climb up to at least 2,500. If i push the gas pedal it will rev up and drop down to 1,500 rpms and then the up and down starts from 1,500 to 2,100 rpms non stop. I took the fast idle valve off, cleaned it thoroughly, put it back on, started the car, and it was exactly the same. After just now reading another thread on here it said that if u take the cap off of the fast idle valve, start the car, put ur finger over the hole in the valve, then it should idle back to normal. I did this and it still idled exactly the same. I also took a screw driver and pushed the valve down while it was running, it revved way up higher, but still did the up and down at the same time....so i guess it can't be that?!?! So now, im guessing it is the TPS. If it is the TPS i noticed that it is rivitted (sp?) onto the throttle, which sucks *slaps Honda* would my best bet be to buy a whole throttle assembly at a junkyard (not sure what that would cost) and stick it on mine? or if anyone thinks it may be the Fast Idle Valve for sure, i can get one of those at a junkyard for 15 bucks. Anyone have any comments/suggestions/solutions/tests, please feal free to post, i really need to get this fixed. -Thanks

[Deadhead]

ok... if putting your finger in the center of the FICV did not settle down the idle, then that is not your problem. It's possible that it is your TPS, but I honestly don't remember there being a TPS on the accord I had (86 LX-i hatch). Please someone correct me if i'm wrong about that.

Honda does rivet them onto the back of the throttle body in every case i've seen. Just take a dremel and cut into the top of the rivit until you can get a flathead screwdriver to unscrew it. I used a hacksaw, but that was a bitch and a half lol.

You will also have to recalibrate your TPS if you replace it, so keep that in mind also... calibrating is not going to requre a multimeter and your going to have to check for resistance between points on the sensor. I'm not sure on the procedure if there is one for this. So check these things first.

1. Check for vacuum leaks
2. Check your cooling system for leaks and air pockets
3. Is your CEL on?

[twstice]

Im going to go check for vacuum leaks right now, i just bought a bottle of carb cleaner. And i looked at the shop manual and it looks as if what im calling the TPS is actually a "Throttle Angle Sensor" ....which sounds about the same lol, im not sure. What is a CEL though?

[twstice]

i just got done testing some stuff, here is what i did : Checked all vacuum lines with carb cleaner - I found no vacuum leaks ; Disconnected the Throttle Angle Sensor while the car was running - The check engine light came on but The idle didn't change at all, still up down up down up down, so im curious about that ; I also checked the Fast Idle Valve for the heck of it - Seems to be in perfect working condition. ; Disconnected the EGR valve at the electrical plug while it was running and nothing changed at all, also disconnected the vacuum line running to the EGR while the engine was running and nothing changed. ; I looked for the Idle Control Solenoid valve, and oddly i didnt find it o.O ; Im so lost now :(

[maxsideburn]

If you're car is an EFI make sure you have a decent fluid levels on all your fluids. Then unplug the battery for 5 minutes or so. Sometimes resetting the ECU can fix little problems like this. If you're carbed then I would definately think a vacuum leak, a pretty bad one for a carbed car to be doing that.

[twstice]

Alright, i will do that tomorrow and let you know what happens. Thanks!

[Shadowkat]

Have you done any coolant system work recently? I had drained my radiator when i was doing my engine swap and when the car was finally done i just filled it and started the car instead of bleeding the air out of the system like you're supposed to. So then, as you said, the car would rev up really high, then when the engine would warm up, the idle would become spastic. It would rev up then drop off, then rev up, then drop off. It did that because the air in the coolant system gave the temperature sensor false readings. I would try topping off your coolant levels and bleeding the system.

[twstice]

I havent done any coolant work, but i did notice that the coolant was low. I filled the radiator back up, then i started the car and nothing was different. Maybe i should have reset the computer after filling the coolant? ....But one weird thing is i checked the coolant again the next day and it looked low again... Maybe there is a leak somewhere, but i dont have a clue where. The car never runs hot at all, it's always at the same temp on the gauge when it warms up. I'll update what i've done this afternoon. Thanks!

[maxsideburn]

Turn the car on, then fill the radiator with the motor running. Then disconnect your battery for a while like I said and reset your ECU. The same thing happened to me when I changed my thermostat.

[twstice]

I filled the radiator while it was runnin, then disconnected the battery, waited about 10 mins, then put the battery back on, started the car and it was still the same :( . One weird thing though, while i was filling it, there for a few seconds, the engine started doing its up down up down up down at a lower idle : around 1100 to 2000 instead of the normal up down at 1500 to (2100-2500). But it only did that for a few seconds.

[twstice]

Maybe that means the coolant system is what's wrong? is there any ways i can check it for sure, like check the temperature sensor some how? Or how do i bleed the system or check for air in the system? -Thanks

[maxsideburn]

yeah, my guess would be something with the coolant system. I mean if mine did that when I was low on coolant (just changed the thermostat) and yours changed the way it idled a bit WHILE adding coolant, then I would think you have some kind of coolant problem. Do you have any coolant leaks at all?

[twstice]

I dont have any leaks that i know of, BUT like i mentioned earlier, no coolant was visible at the top of the radiator when i first checked it (only brown wetness where it had been while running) and I also found that it was low today too, meaning i didnt see any when i took the cap off... I dont see any obvious leaks, except for it looks wet around one of the hoses somehow tied to the coolant system. Let me try to explain what it is : Inside the car, on the dash, between the two center vents, there is a little black lever that u can move up and down, if u move it up it shows a blue man (meaning blow cooler air i guess) and if u move it down it shows a white man (meaning blow the normal fan i guess) And when u move that lever it runs to an assembly with a cable that is connected to a coolant hose near the firewall. I guess it opens and closes with the lever. That little valve looks wet always, maybe there is a slow leak there?

[Shadowkat]

I dont have any leaks that i know of, BUT like i mentioned earlier, no coolant was visible at the top of the radiator when i first checked it (only brown wetness where it had been while running) and I also found that it was low today too, meaning i didnt see any when i took the cap off... I dont see any obvious leaks, except for it looks wet around one of the hoses somehow tied to the coolant system. Let me try to explain what it is : Inside the car, on the dash, between the two center vents, there is a little black lever that u can move up and down, if u move it up it shows a blue man (meaning blow cooler air i guess) and if u move it down it shows a white man (meaning blow the normal fan i guess) And when u move that lever it runs to an assembly with a cable that is connected to a coolant hose near the firewall. I guess it opens and closes with the lever. That little valve looks wet always, maybe there is a slow leak there?
Okay, it does sound coolent related. The thing is, you said you refilled the radiator with fluid, but you didn't say that you bled the air out of the system. That's the important part to get rid of any coolant related idle problems. Like I said, when I filled my coolent system, it was the air inside the lines that caused a spastic idle because it was giving false temp readings. I suggest following the correct coolant filling procedure outlined in the factory service manual or chilton's manual. If you don't have either of these, i can do a write up on how to bleed the system if you need.

IMPORTANT!!! I would also check to see if your passenger-side carpet(under the floor mat) is wet with coolant. The valve you said is wet by the firewall is the valve controlling how much engine coolant goes to your heater core. If that valve is leaking, it could be indicative of a heater core leak which would result in a wet passenger side carpet.

Try bleeding the air to fix the idle, and check the carpet and get back to us. I had to replace my heater core when something similar to your situation was happening to me, so I might be able to help!

[twstice]

I just checked the passenger carpet, it is all dry, not a hint of moisture anywhere. I don't have either of those manuals, so i'd really appreciate it if you could do a quick write up on how to do it. -Thanks!

[twstice]

I noticed another thing when i was doin some of this testing, when i would turn the engine on and let it run for a bit, when i turned it off, i could hear a gurggling sound in the engine compartment. Sounds like the coolant moving around a lot. Im not sure if this is normal or not?, i dont think ive ever noticed it before.

[Shadowkat]

I just checked the passenger carpet, it is all dry, not a hint of moisture anywhere. I don't have either of those manuals, so i'd really appreciate it if you could do a quick write up on how to do it. -Thanks!

How to fill coolant system properly, including bleeding the air from the system.

1) Drain radiator(if you are completely replacing old fluid)
2) Loosen the cooling system bleed bolt located on the top of the thermostat housing. (a couple turns should be plenty loose)
3) Using a solution of 50% DISTILLED water, and 50% anti-freeze, fill the radiator via the cap on the top.
4) When coolant flows steadily without air bubbles from the BLEED BOLT, close the bleed bolt and finish filling the radiator up to the bottom of the base of the neck.
5) With the radiator cap off, and the heater control in the cabin set to Hot, start the engine and let it idle up to oporating temperature (temp guage needle about halfway up, and it's recommended that you let the cooling fan cylce on at least twice).
6) Once the engine has reached operating temperature, top off the radiator with fluid, and keep watching for 5 ish more minutes to make sure the level is stablized. Once the fluid levelis stable, close the radiator cap and tighten it properly.

After you do this, turn off the car and let it cool down for quite some time. Then start the car again, and see if you still have the idle problem as it warms up(i'd watch it for at least 10-15 minutes)

If the idle problem is still there, then your idle problem is for sure not related to the cooling system, and my guess is that your idle problem is related to a different sensor malcuntioning, or a vaccum leak somewhere.

Good luck, and i hope this helps, let me know if bleeding the air helped the problem at all.

[Shadowkat]

here are a couple pictures of where the coolant bleed bolt is located on the thermostat housing. I hope this will help you located it better.

http://i24.photobucket.com/albums/c22/shadowkat1/coolantbleedbolt2.jpg

http://i24.photobucket.com/albums/c22/shadowkat1/coolantbleedbolt1.jpg

[CruzenNC]

Don't know if this will help, I had similar problems and I did two things. One which was bleed the air out of coolant system. The other was replace my AIT sensor on intake manifold. Only because the ECU threw the 10 blink code. My idle is now steady at about 900rpm, but it still goes to like 2200rpm at startup, then drops after about 30sec or if I give it gas, it drops back down to 900rpm.

[l3aLLa]

I had a similiar problem with my 86 lxi fi. I checked over vacume leaks many times and the whole time, it was right in front of me. I had a vacume hose break which caused high idles and jumping in idles. I also had went to every vacume hose and pinched them off to see if the idle would settle. It ended up just being the one hose, which i ended up just plugging off.

[modu03]

i have a similar problem riight now, it sits at around 2000 rpm after start up,which is actually normal for these cars, according to honda. as sson as the car starts moving it holds steady at 3000 and will keep the car driving down the road. 2 seconds after i stop. it drops to normal idle....

if i disconnect the eacv (air control valve) it idles fine, but the check engine light comes on. there is nothing wrong with the eacv, the computer is telling it to set the idle up that high... i haven't been able to figure out exactly what is causing this

[l3aLLa]

When I had fixed my vacume hose, I had to set the idle down, now when it warms up in the morning, its usually about 1200-1400 RPMS, and within 20 seconds is at a normal idle of about 750-800 RPMS.

[CruzenNC]

had a similiar problem with my 86 lxi fi. I checked over vacume leaks many times and the whole time, it was right in front of me. I had a vacume hose break which caused high idles and jumping in idles. I also had went to every vacume hose and pinched them off to see if the idle would settle. It ended up just being the one hose, which i ended up just plugging off.

What is best way to check for vacuum leaks?

l3aLLa - what hose was it that you plugged

[bobafett]

did you try simply adjusting the fast idle valve? take a really large standard screwdriver and spin the top part clockwise a couple turns. that solved all of my erratic idle issues. :D

['A20A3']

I know this sounds like a noob question but where is the fast idle valve?

Does anyone have a pic?

[bobafett]

its on the BACK of the intake manifold, near the throttle body.

it will have 2 screws or bolts holding a little plate onto the top of it. take off that plate, and use a large standard screwdriver or a quarter or something to turn the center peice clockwise to lower the fast idle. :)

[Shadowkat]

be careful when adjusting the fast idle screw though, it may fix the symptoms but not the problem. If there is something causeing your idle to be too low or too high, simply adjusting the idle screw will fix the idle for the time being yes, but it may not fix the problem causing the idle to become off in the first place.

EDIT: oops, i thought this thread was newer for some reason, didn't mean to revive an old thread, but my car's been having another idle problem so I was browsing around for idle threads and posted on this one because i thought it was newer. However, since I've posted on this one, maybe someone can help me.

Recently my car has been having an idle problem only when going through the cold weather warmup sequence. When it's cold out side the idle moves up and down between 1 and 2 thousand rpm until the car is warmed up. Does anyone out there know what could have caused this problem? Please Help!

[blaze one]

I just bought a 88 lxi Automatic sedan .

It has done this " erratic jumping" at idle , when cold out , . But it always goes away once the engine warms up in 2 mins. or so .
Maybe it is Honda's way of bringing in warm air from the engine .

[Shadowkat]

Me again back to revive this post yet again. Now that winter is thoroughly upon us (here in Illinois) my cold weather start-up idle problem is at it's worst.

The symptoms: When the engine is starting in cold weather and warming up, the rpms move up up from 1000 to 2000 and then drop quickly back down to 1000. This happens repeatedly in close succession and continues until the car is at operation temperature.

Possible causes: I'm thinking it has something to do with my vacuum lines or possibly fuel delivery. My guess is vacuum lines but I'm not sure how to test this or even if it makes sense that it would be the probem. I also say fuel delivery because I have been smelling gas vapor in the interior an have noticed some visible stains around the injectors and I thought that maybe it was having a hard time getting fuel when running cold because there is also clearly a problem w/ the injectors/seals as seen by the stains.

Solutions? I would really like to take cae of this problem this winter before it gets worse. If anyne has any testing/fixing suggestions they would be greatly appreciates.

Thanks all.

[Shadowkat]

Don't tell me no one else has had this problem... Please, if anyone has any suggestions I would very much appreciate them.

[shepherd79]

check the coolant level. make sure it is toped off and you have enough coolant in overflow tank.
if that doesn't fix it.
locate the fast idle valve. it is on the back of the Throttle body. unscrew two screws and remove the top. use large flat screw driver turn the clock wise direction untill rpm stop jumping.
put everything back and you are done.

[w261w261]

make sure you don't have any air bubbles in the system. unscrew the bleed valve by the thermostat, turn the heater on full heat, and let the water fountain out until no bubbles. an air bubble can make the idle valve behave as you've stated.

[Shadowkat]

I know for a fact it's not air in the coolant system. I know this because I already discovered that problem and fixed it recently when I replaced my malfunctioning heater core. In fact, I was the one that suggested that problem to someone else on this forum earlier beacause I had already discovered that problem. So I know it's not air in the coolant. And the fast idle control valve only raises and lowers the idle speed I thought, so in essence adjusting that would cause my engine to idle high all the time, thus covering up my probem but not fixing it if I'm not mistaken. Does anyone know of any other possible causes for this? could it be vaccum problems like i originally thought, or would that not cause this?

[Fushi]

Bump !
I'm just having the same problem.
This afternoon, I'll try to bleed the air out of the coolant since I didn't do this after the swap.
I'll post my results here if something changes.

The problem is : The idle is bouncy, between 1100/2000rpm.

I'll also check for coolant leak.

[88Accord-DX]

An engine with EFI surges at idle only when at operating temperature. The MOST LIKELY cause would be a bad coolant temperature sensor.

Not that I have a EFI Accord. Just one of my ASE test questions I have.

[MessyHonda]

An engine with EFI surges at idle only when at operating temperature. The MOST LIKELY cause would be a bad coolant temperature sensor.
Not that I have a EFI Accord. Just one of my ASE test questions I have.

yay your back.....:welcome:

[Fushi]

I've bled the air out of the coolant, and it didn't solve anything... :crying:
I'm feeling depressed.
I have to figure out what the problem is !

[maxsideburn]

just be glad you have a 3G, you can figure this problem out. I've been battling the surging idle issue with my 90 Accord Coupe since I bought it, and I don't think I'll ever get it sorted out.

[Fushi]

My idle problem is now solved !
In fact, the throttle cable was a little too tight... :Owned:

Everything is now working the way it should :)

[Tecknixia]

And the fast idle control valve only raises and lowers the idle speed I thought, so in essence adjusting that would cause my engine to idle high all the time, thus covering up my probem but not fixing it if I'm not mistaken. Does anyone know of any other possible causes for this? could it be vaccum problems like i originally thought, or would that not cause this?

The idle screw controls the idle speed... the FAST idle valve sends more air into the intake manifold to aid in warming up the engine by creating it to rev higher when the coolant is cold.

When this valve is loose, it sends too much air into the engine... which causes the engine to rev too high. The ecu senses this and cuts the injectors, which causes the rpms to drop back down to an acceptable speed. Since the same amount of air is still going into the engine, it revs up again until injectors cut out, and it continues in this cycle... that is what causes the irratic idle at warmup.

When the car warms up, the valve closes completely and you get your normal idle.

Under the FIV (fast idle valve) cap is a plastic peice that is screwed down into the valve... over time this piece will turn and loosen, which allows the FIV to send more air into the engine then it should. When this is screwed back down, the valve should then be operating normally.

[skyline95770]

I don't know if this is still a problem for any carb Honda cars use what I call a crush gasket between the intake manifold and carburettor and it works the first time when you tighten it down but over time it develops leaks.my 79 accord had this problem and it mimics the ficv jumping rpm to a tee.i could learn my weight on the air cleaner and get the idle to change or spray something around base of carb , but it is hard to get around the entire carb.

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