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pink_sleeve
04-27-2011, 02:25 AM
I know the car is supposed to idle around 800rpm... Mine has idled between that and 1000 for the most part. Now for the past few days the idle wants to stay around 1300 to 1500 and it idles higher and higher the longer you drive it up into the 1800 range :( ... Any idea what would or can cause this? The temps outside have been down in the 30s and 40s and below for the winter. The last few days have been 50 to 70s and this is when the idle has been acting funny.

Xaisk
04-27-2011, 05:12 AM
I know the car is supposed to idle around 800rpm... Mine has idled between that and 1000 for the most part. Now for the past few days the idle wants to stay around 1300 to 1500 and it idles higher and higher the longer you drive it up into the 1800 range :( ... Any idea what would or can cause this? The temps outside have been down in the 30s and 40s and below for the winter. The last few days have been 50 to 70s and this is when the idle has been acting funny.

I had a simliar issue to this while I still had my stock carb. My problem was I would drive and as I gave it gas it would come back down but not back to idle, it would be slightly above and it would keep going up like 50-100 RPM everytime it happened. Sometimes if I hit the pedal hard to rev it, it would unstick it. I finally got aggravated and took the air cleaner off. The metal plate in the throat of the carb had gotten gunked up and was having trouble shutting properly. A can of carb cleaner solved the issue for me.

Buzo
04-27-2011, 03:19 PM
There are a few things that controll the throttle position at idle

1) The accelerator linkage. Check the pedal and TV cables return is free.
2) The automatic throttle controller. It is the vacuum actuator in the passenger side of the car. It is normally extended, so check it is extended when the car is off and it must get pulled as soon as the car builds vacuum, leaving the throttle loose. If the hose has a leak, the actuator will remain extended.
3) If your car is automatic, there is the Idle Boost Controller in the driver side of the car. It gets vacuum when the car is cold or when the car is in any shift other than P or N.
4) The choke. Again in the passenger side there is a piece of metal with several steps and a screw sitting on it. The higher step when cold and the smaller step when the engine is hot.
5) The throttle itself as Xaisk mantioned below.

pink_sleeve
04-27-2011, 06:21 PM
Thanks for the info guys. I will try to check those things out tomorrow. However today the idle would not come below 1500 at all and it was jumping from 1500 to 2000. Up and down.

Buzo
04-27-2011, 07:40 PM
Thanks for the info guys. I will try to check those things out tomorrow. However today the idle would not come below 1500 at all and it was jumping from 1500 to 2000. Up and down.

So only the 2) and 3) from my list below can cause the intermittent problem you have.

So look straight to the actuators (they both have an screw with a spring to adjust the idle speed) you need to lift the air filter (no need to disconnect it completelly, just lift it with all the vacuum hoses still connected, so you can inspect the actuators).

If your car is automatic I'm almost sure the cause of your problem is going to be the idle boost controller in the driver's side. And the root cause will be a malfunction in the ECU underneath the driver's seat.

Before you buy a new ECU, loose the screws (one at the time) and check which actuator is moving in and out. You can use your car with the screws loose as long as you have good Idle RPMs in P to keep good RPMS in D.

pink_sleeve
04-27-2011, 10:05 PM
So only the 2) and 3) from my list below can cause the intermittent problem you have.

So look straight to the actuators (they both have an screw with a spring to adjust the idle speed) you need to lift the air filter (no need to disconnect it completelly, just lift it with all the vacuum hoses still connected, so you can inspect the actuators).

If your car is automatic I'm almost sure the cause of your problem is going to be the idle boost controller in the driver's side. And the root cause will be a malfunction in the ECU underneath the driver's seat.

Before you buy a new ECU, loose the screws (one at the time) and check which actuator is moving in and out. You can use your car with the screws loose as long as you have good Idle RPMs in P to keep good RPMS in D.

My car is a manual....

pink_sleeve
04-28-2011, 02:41 AM
Now the car is idling at 2500 and won't come down :( idk what gives... Any other clues?

TotaledTL
04-28-2011, 07:06 AM
...idle boost controller in the driver's side. And the root cause will be a malfunction in the ECU underneath the driver's seat...

Do the ECUs fail in this fashion frequently? Not more likely to be a vacuum line and/or a solenoid?

Xaisk
04-28-2011, 08:04 AM
To be honest these old carburetors are such a pain in the ass to repair. Mine eventually started idling up and down from 1500 - 2000 and it wouldnt stop. I couldnt source the problem even after checking every damn solenoid in the car, so I did a weber conversion. Runs like a damned champ.

pink_sleeve
04-29-2011, 03:24 PM
Ok i have tried to check the things you guys mentioned with no luck so i decided to manually turn the idle down with the idle screw. The car ran fine yesterday and was idling around 800ish but was hard to start. Now today the car is back up to idling at 2000 to 2500 solid. WTF :banghead:

Buzo
04-29-2011, 07:01 PM
Do the ECUs fail in this fashion frequently? Not more likely to be a vacuum line and/or a solenoid?

When the solenoid is intermittent, switching on and off at a fixed frequency then the ECU may be the problem.
If the issue is always on or always off then the wiring or the solenoids are the common causes.

However, a lot of checks must be done before replacing the ECU, including testing with a known good ECU.

Buzo
04-29-2011, 07:08 PM
My car is a manual....

You should tell me that before haha,

The choke or the frequency solenoid C which drives the idle controller remain as a possible cause.

I would leave the idle controller out of the play by backing the screw off all the way, then you may need to compensate your idle speed with the idle stop adjust.

There are two different sympthoms here, one is the intermittent Idle speed going up and down, and the other is staying always up. Two different causes.

Buzo
04-29-2011, 07:22 PM
To be honest these old carburetors are such a pain in the ass to repair. Mine eventually started idling up and down from 1500 - 2000 and it wouldnt stop. I couldnt source the problem even after checking every damn solenoid in the car, so I did a weber conversion. Runs like a damned champ.

My car did that to me and fixed it replacing the ECU. A $15 USD fix.

g.frost
04-29-2011, 08:26 PM
Did you check, after the engine is warmed up, to make sure the choke is fully open and the fast idle cam has fully unloaded?

Demon1024
04-29-2011, 09:57 PM
If you haven't i highly suggest the vacuum removal. Check/replace all the vacuum lines / routes.

pink_sleeve
04-29-2011, 10:08 PM
If you haven't i highly suggest the vacuum removal. Check/replace all the vacuum lines / routes.

What are the things on the driver side of the car that the vacuum lines run to up near the fender?

rocketman
04-30-2011, 08:19 AM
If you intend on keeping the car I'd suggest spending the $$ for the Weber today. The old Honda carbs (this one is 22 years old!) are such a pain . . . I tried to diagnose and fix mine for YEARS, did anything I could think of . . . finally sent to a Weber, runs GREAT! That was 200,000 miles ago. Rocketman

g.frost
04-30-2011, 06:20 PM
You will have to put a technician hat on to actually diagnose the problem. Then read the manual for test procedures. Mine idles at 2000 and 1500 rpm every time I start it cold. When it warms up (more or less....) it idles down. So one good suspect is the mechanism that controls the cold/fast idle.

Do you have a vacuum gauge? Warm up the car, pull off the air cleaner and test the 'fast idle unloader'. (download the manual) Unpug the vacuum line and pump down the fast idle unloader. Does the idle drop to 800rpm? Yes/No? follow the vac line ... thermo valve A, is it open? ...now to the choke opener: do you have good vacuum on line 18 from the choke opener?

My 88 only has 154K miles, but original carb has never been opened. It needed to replace the choke opener and a thermovalve a couple years ago.

88Accord-DX
04-30-2011, 10:00 PM
To be honest these old carburetors are such a pain in the ass to repair. Mine eventually started idling up and down from 1500 - 2000 and it wouldnt stop. I couldnt source the problem even after checking every damn solenoid in the car, so I did a weber conversion. Runs like a damned champ.


If you intend on keeping the car I'd suggest spending the $$ for the Weber today. The old Honda carbs (this one is 22 years old!) are such a pain . . . I tried to diagnose and fix mine for YEARS, did anything I could think of . . . finally sent to a Weber, runs GREAT! That was 200,000 miles ago. Rocketman

Both these guys know what I know about these carbs! :cheers:
Weber is the way to go by far. Lost lots of time fooling with it, cause of how finicky these carbs are with all the vacuum lines & solenoids.. You can only beat a dead horse for so long. :deadhorse:

Buzo has some serious carb diagnostic equiptment by far, more advanced for the average Joe.

pink_sleeve
04-30-2011, 10:45 PM
Both these guys know what I know about these carbs! :cheers:
Weber is the way to go by far. Lost lots of time fooling with it, cause of how finicky these carbs are with all the vacuum lines & solenoids.. You can only beat a dead horse for so long. :deadhorse:

Buzo has some serious carb diagnostic equiptment by far, more advanced for the average Joe.

Is ebay the only source for Weber carbs or can they be found cheaper then $325?

88Accord-DX
04-30-2011, 11:41 PM
I think some other sources are carbs unlimited. I just bought a used one off ebay & rebuilt it for about $150.. The weber is easier to rebuild than the OEM Keihien carb.

Dr_Snooz
05-01-2011, 09:41 AM
I believe those Webers came stock on some cars. A little internet research and some trips to the junkyard might be worthwhile.

pink_sleeve
05-02-2011, 06:24 PM
You should tell me that before haha,

The choke or the frequency solenoid C which drives the idle controller remain as a possible cause.

I would leave the idle controller out of the play by backing the screw off all the way, then you may need to compensate your idle speed with the idle stop adjust.

There are two different sympthoms here, one is the intermittent Idle speed going up and down, and the other is staying always up. Two different causes.

How do you properly check the choke? I am not all that familiar with carbs :( Also is there a diagram somewhere so I can find this frequency solenoid? The car still keeps idling around 2 grand and sometimes does the 1500 2000 jump up and down. What can be harmed with it idling this high bc I don't have a ton of money to dump into this fix at the moment and from what I have read you can't use the Weber carb if you have to take an emissions test which I do have to do in about 6 weeks or less. Right now this is my only form of transportation and is only driven 5 to 10 miles at a time. Thanks again for the help guys

pink_sleeve
05-04-2011, 01:55 PM
Well I haven't been able to solve the problem and it just idles at 2500 solid now every time I start it. I think the high idle has started to take its toll because smoke just rolls from under the hood now and the whole underside of the motor is covered like it has an oil leak so I'm guessing it'll be going to the scrap yard soon :(

TotaledTL
05-04-2011, 06:41 PM
Well I haven't been able to solve the problem and it just idles at 2500 solid now every time I start it. I think the high idle has started to take its toll because smoke just rolls from under the hood now and the whole underside of the motor is covered like it has an oil leak so I'm guessing it'll be going to the scrap yard soon :(

Well keep an eye on the oil level. Did you check the pcv valve? Did you dnload the manual & look for the solenoid, idle screws, etc.? The idle controller, solenoid or whatever controls it was part of my idle issue as Buzo said. I just disconnected it & increased the idle w/ the throttle stop screw. Don't just give up & scrap it-:banghead:

Dr_Snooz
05-04-2011, 06:56 PM
If you can't fix it yourself, take it to a shop.

pink_sleeve
05-04-2011, 07:41 PM
Well keep an eye on the oil level. Did you check the pcv valve? Did you dnload the manual & look for the solenoid, idle screws, etc.? The idle controller, solenoid or whatever controls it was part of my idle issue as Buzo said. I just disconnected it & increased the idle w/ the throttle stop screw. Don't just give up & scrap it-:banghead:

I thought the idle control thing was only on automatics? I have really only browsed the site from my phone and not everything downloads. I don't want to give up on the car because I really do like the car. But I also don't have the kind of money a mechanics shop will want to fix and diagnose a carb problem since most shops are clueless when it comes to older Hondas or so it seems atleast in my area.

Pnem3
05-04-2011, 08:02 PM
For what it is worth, my car idled high a month ago and I just backed off of the main idle screw and it runs fine now. I think that months of cold starts and high idle let the screw turn by itself somehow. Stranger things have happened.

rocketman
05-05-2011, 06:19 AM
Sounds exactly like what my '89 was doing . . . when it started to run fast . . . like 2500 all the time . . . I had enough and scrapped the original carb for the Weber. And believe me I tried everything mentioned here and then some. Hours and hours . . . checked every vacuum line (and you know what that can be like), every electrical connection, cans of carb cleaner, played with the choke, adjusted it again and again, still ran around 2500 rpm. Pissed me off to no end! If I remember right it (the Weber) was less than $200, but what a change! Runs great! And that was over 200,000 miles ago . . . still runs great, never skipped a beat, never touched the Weber, a good upgrade. If your Accord is otherwise in good shape, I'd say shut if off, look for a used Weber (junkyard or e-bay) and put it on. You won't believe it. Rocketman

Dr_Snooz
05-05-2011, 07:59 AM
He has to pass emissions so I don't think the Weber is a solution for him.

At some point, every carb needs an overhaul. You have to pull it apart and replace all the worn out stuff. You have to test every vacuum control, every dash pot, every electric solenoid and replace every piece that isn't within tolerance. Most importantly, you have to put it all back together such that it runs and passes smog. These are pretty complicated carbs, so probably not a good choice for your first carb rebuild.

Basically, these are your choices:

1. Buy a rebuilt carb
2. Take it to a shop and hope for the best
3. Buy a Weber and try to sneak it through your next (and all subsequent) emissions tests
4. Scrap the car

If I were in your shoes, I would make absolutely certain that you don't have a vacuum leak. It really sounds like you do. If that doesn't get it, I would drive the car to a dealer's service center. Ask to talk to the Service Manager and explain your situation. Ask him if he has a tech still on staff who might have worked on these cars back in the day and can tell you how to fix it. He may be able to help. Or he may tell you to get lost, or if he's dishonest, he'll see a golden opportunity to pull your pants down and give it to you proper. If you don't get help at one dealership, go to the next and the next and keep going.

If you decide that you want to fix it, remember that you are driving an old car. You only fix one issue when the next issue arises to take its place. You need to find a strategy for fixing things, whether it's finding a good shop or learning to diagnose and fix things yourself. You can't just drive around in a car that isn't running properly, not fix the problems and expect good results.

Dr_Snooz
05-05-2011, 07:59 AM
PS: I'd also fix your oil leak.

g.frost
05-05-2011, 08:47 PM
When my idle hung at 2000+rpm (and eventually raced on above 3000rpm... look out) It traced to a vacuum leak in the choke opener diaphragm. This prevented the choke from fully opening (hey it's 'normally closed'!) and also prevented the fast idle unloader from getting required vac. OEM choke opener from Majestic fixed it. Also replaced a few vac lines around the carb that had become brittle with exposure to gas. The rest of the vac lines are all original....

The only other issue I've had with this carb in 23 years is the erratic idle down when cold. Sometimes it wants to idle(or stumble & stall) at 250-300 rpm. This problem I had to the dealer when the car was new, under the 12K mile warranty. (He tried to blame it on contaminated gas) No mechanic has ever been able to fix it! Doesn't happen very often though so it is extra hard to diagnose. Since I switched to Redline oil 8 years ago(to stop the valve guides leaking...), now it just idles on at 250rpm without stumbling or stalling, amazing. Overall I can't complain too much as it has always passed CA emissions by a mile and gets 26/34 mpg city/hiway. Ok I better shut up and not boast too much, I think it may be listening, it might want to prove me wrong & mess up tomorrow. I treat it nice and give it a maintenance dose of Redline SI1 fuel cleaner with each tank.

Demon1024
05-05-2011, 09:43 PM
your car idles at 250 rpm? Really?

I'd love to get a video of that with some kind of louder(than stock) exhaust system. And how? Set my idle to like 1k on most my cars, under 500 usually tries to die.

Dr_Snooz
05-06-2011, 07:37 AM
I think the old Hondas don't like the cold. That's when they always mess up in ways that you just can't figure out.

Bones7201
05-12-2011, 12:35 PM
Sounds like the same issue I have now.. Mine was fine until it got warm and now the idle at cold is perfect and when hot it hits 2k plus easy.

I am going to check into it after I check some diagrams and such.

TotaledTL
05-12-2011, 07:39 PM
Sounds like the same issue I have now.. Mine was fine until it got warm and now the idle at cold is perfect and when hot it hits 2k plus easy.

I am going to check into it after I check some diagrams and such.

I have the opposite problem. Now that the temp. is getting to be 80 degrees + here the idle drops to 500 or less, intermittently, occasionally dying (auto transm., only when in gear does this occur).

Bones7201
05-12-2011, 09:01 PM
I have the opposite problem. Now that the temp. is getting to be 80 degrees + here the idle drops to 500 or less, intermittently, occasionally dying (auto transm., only when in gear does this occur).

Found mine....

I just recently bought my accord and was driving up the road and the idle kept getting higher and higher... like 4k. So............long story short the last owner was a douche and adjusted the throttle linkage to adjust the idle up when there was a vacuum leak and the idle screw was backed out all the way so when I found the loose linkage got that fixed...

I was a head ache.. some people should NOT work on cars EVER!!!! :gun:

2oodoor
05-13-2011, 03:39 AM
The fast idle diaphragm and choke unloader are separate, which is retarded.

Next time it is idled up too high try pulling the vac line off the thermowax valves one at at time. Hold your finger over the end of the vacuum source there. If the idle changes to "normal" that would be are either low on coolant or the valve is not working right. Of course this is not a perfect science but it would give you a piece of the puzzle to use for diagnostic logic.

Otherwise there are a dozen causes for this same problem.
When I was using the oem carb I just took the fast idle hardware off the carb, putting the screws back in afterwards. Also I removed the choke rod going to the butterfly and wired the choke butterfly to stay open all the time.
Too high idle issues disappeared, and it still cranked fine on cold mornings.
That would allow the car to possibly pass emmisions testing I would think, as long as everything else is working right.

You can also check on the drivers side of the carb, the secondary diaphram controller sometimes holds the secondary throttle open slightley which would cause the too low idle as well as the too high depending on the other conditions there such as vac leaks, compensated settings to overcome other issues etc..

You could very well replace the carb with a perfect one and still have the same issue because of all the other controls for the carb in the black box and the thermovalves. arghhh

It is a real pain in the ass to deal with the breather assembly every time you check the carb, this adds to the quandry. I would try plugging off all vac lines that are open when the breather is off, and work with it like that but not drive it much without air cleaner as it will ruin the piston rings.

If the vac advance diaphragm is leaking, which can be intermitant, it also would be a hard to trace vac leak that would rob the vac needed to hold pressure on the fast idle or any other diaphragms for that matter.

TotaledTL
05-13-2011, 05:16 AM
By far this %^#@! carb. & associated rat's nest of vac. lines, solenoids, etc. is the most frustrating thing to deal with on this car. I got rid of freq. sol. C & some sort of vac. chamber associated with it & got rid of the intermittent high idle. Now it's the opposite problem. I wish I had waited & found a FI model but it's too late now.... aarrgh....

g.frost
05-13-2011, 02:06 PM
As roodoo mentioned, you can wire the choke and/or high idle open if that's where the problem is. I did this until parts arrived. As long as it's not too cold out you can pump and feather the gas pedal to get going without the choke.

g.frost
05-13-2011, 02:23 PM
I have the opposite problem. Now that the temp. is getting to be 80 degrees + here the idle drops to 500 or less, intermittently, occasionally dying (auto transm., only when in gear does this occur).

My 88 does the same in warm weather; it wants to idle down before it's warmed up. The Manual is in Neutral so it idles on at 4-500. Put the Auto in Neutral, it's easier than trying to fix it.

g.frost
05-21-2011, 01:40 PM
Now the car is idling at 2500 and won't come down :( idk what gives... Any other clues?

It would be interesting to hear how you fixed it. :cheers: