89 Accord Idle problem

ephebert · #1 01-04-2005, 08:56 PM

I have an 89 accord with a 2bl 2.0L 5sp Manual. WHen I reach normal operating temp the idle is a shot in the dark. It might work fine for a bit 700-800rmp then it might dip down to 200-300rpm or stall. I have had this problem on 3 different Honda's and it dies when fast idle is no longer in the picture.

On my 78 Civic I had the carb rebuilt to try and correct it. It didn't work. On my 82 Prelude I had the clutch rebuilt because an "expert" said that was the cause.... it still died. Now with this 89 Accord I have found that cleaning the carb out helps a bit but I know it isn't fuel related but ait or air/fuel mix related. I did read about in the forum that the IACV (Idle Air Control Valve) should be cleaned out and it should take care of the issue. If the 89 Accord has one I can't find it. I can find the Idle Stop Solenoid but I don't know if this is the same as the IACV.

Need some help. SO far I have replaced the O2 sensor, PCV, Air, Fuel (primary and Secondary), ERG, Oil. The previous owner thinks the Idle jet is gummed up but if it were I would see the idle have more major issues then just every once in a while. The Accord does idle about 600-700 on a good day with out major problems.

Yuu89Lxi · #2 01-05-2005, 04:19 PM

I recently had similar trouble... Did you check your Electronic Control Unit (ECU).
It would be located underneath your driver's seat.

Mine got flooded and the circuits corroded, causing my engine to act funny... The ECU reported that it was an Idle Control issue, but it was the ECU itself. I went to a wrecking yard and got a new one. but you have to be sure to get the EXACT right one or your car will run like crap.

ephebert · #3 01-06-2005, 02:38 AM

I am going to look at the ECU this weekend. I still feel it is a sensor or vacuum problem somewhere. The replacement ECU for it is $300 so if it needs it the junkyard here i come.

Thanks for helping.

Yuu89Lxi · #4 01-06-2005, 12:57 PM

The most expensive I found an ECU was $125... and that's in California... surely Oregon can't be more expensive. I got mine for $45. If it is your ECU, do some shopping.

ephebert · #5 01-06-2005, 02:38 PM

Ok, checked the ECU and do not see any lights on. I even pulled the fuse to clear it of any errors. The O2 sensor was very ugly when I replaced it.

When looking at the ECU through that little door I really don't see an LED anywhere. Does the Carb version of an 89 Accord have an ECU with an LED? I can see a little part of PCB (Printed Circuit Board) but not an LED from the view I have.

Where to go from here?

slipknotcraig133 · #6 01-06-2005, 03:35 PM

I had the same problem with my 86 lxi. First check your air screw. Im not sure were it is at on the carbed cars. Next check your o2 sensor and your egr.

EDIT: Also check your map sensor. I talked to a person on a different accord forum and there map sensor is bad but it is not throwing a code. I changed mine and it helped my idle and got rid of my bog that i had. Then i messed with my air screw and got it right.

Yuu89Lxi · #7 01-07-2005, 11:53 AM

Yeah... mine is PGM-FI, so I'm not sure about he Carb. But if the ECU matters much on the carb, you might check the circuits.

ephebert · #8 01-16-2005, 04:20 AM

Thanks for all the help. I have been reading and reading and one thing is certain.... it's going to be fun tracking this down. Of course parts are hard to find.

Carb engines don't have MAP or MAFS so it's by valves which are everywhere. Found some good ground to start with over at 3geez and should update in the next week.

ACCORD2 · #9 01-19-2005, 10:06 PM

I have the same problem if you find the solution would you post it please.
TIA

ACCORD2 · #10 01-25-2005, 07:07 PM

Check the intake gasket. Spray some carb cleaner on it and if the thing smooths out that is the problem. I replaced mine today and that was my problem. $4.00 fix.

ephebert · #11 03-10-2005, 04:52 AM

I think I found my problem. After months of research here and at 3geez, in the service manuals and in the Chilton's and Haynes..... it was the thermovalve. Now here's the funny part.

In the Chilton manual it says to pump air pressure into the thermovalve and it should hold on a cold engine. Well it didn't and it said to replace it. At the Honda place where I bought my parts they have the thermovalve as some other peice, it's a a small vavle that has three hose connections. But the part that I tested was on the right side of the Carb. The gas line connects to it. So I found that part and replaced it today.... no more idle issues so far. I have to get a new rim at the junk yard so I am going to see how it holds up. I'll get some pics on the web so you can see what I am talking about.

Thanks to everyone for all the input!!!!

mhendu · #12 10-24-2005, 02:31 PM

Quote:

Originally Posted by ephebert

I think I found my problem. After months of research here and at 3geez, in the service manuals and in the Chilton's and Haynes..... it was the thermovalve. Now here's the funny part.

In the Chilton manual it says to pump air pressure into the thermovalve and it should hold on a cold engine. Well it didn't and it said to replace it. At the Honda place where I bought my parts they have the thermovalve as some other peice, it's a a small vavle that has three hose connections. But the part that I tested was on the right side of the Carb. The gas line connects to it. So I found that part and replaced it today.... no more idle issues so far. I have to get a new rim at the junk yard so I am going to see how it holds up. I'll get some pics on the web so you can see what I am talking about.

Thanks to everyone for all the input!!!!

I have the same problem, but can't figure out what the "thermovalve" is, do you have a part number or another name?

Thanks.

russiankid · #13 10-24-2005, 04:25 PM

change your breather filter, make sure the air filter is clean, have clean fuel filters, clean the carb with carb cleaner, and i adjusted my distributor, that helped alot

ephebert · #14 10-25-2005, 06:07 AM

Quote:

Originally Posted by mhendu

I have the same problem, but can't figure out what the "thermovalve" is, do you have a part number or another name?

Thanks.

Let me check around and get some pictured for you. There is a test you can do that will tell you if it's the part I replaced. Give me a couple days to get this

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