Shurt24

I just bought my 93 Accord (EX). (5 speed)

When i first start it, (cold) it idles perfectly, and runs how a Honda should.
When it warms up, it idles rough.

It will stall occasionally when I slow down or come to a stop.
The stalling will happen more and more the less gas I have in the car.
I get really good gas mileage when I have over a half-tank of gas in the car. It's almost as if these symptoms do not exist until I use half a tank of gas.
It recently began fluctuating it's idle, as well.

I have replaced my 02 sensor.
I have cleaned out the IACV.

I don't know enough about these little cars to have confidence in myself diagnosing them.

I put some more coolant in it, and that seemed to have fixed it (it, being running smoothly when warm and stalling) and it ran great when I drove it to work, but then it started running rough again. (this was before I cleaned out the IACV)

I know there are a thousand posts about this problem, but I just haven't found the one for my situation. I appreciate any help/opinions. Thanks a lot guys.

Dobird78

I had a similar issue and it wound up being the screen filter on my fuel pump. Which means dropping the tank. It's best to replace the pump which comes with a screen filter. You might want to change your fuel filter also, which is located on your firewall passenger side. You could try cleaning your egr valve with a small wire brush, you'll prob need a new gasket. Good luck.

NZXTInerTia

Honestly with the Accords it isn't worth it to drop the tank. Cut a hole in the back, it's completely covered by the trunk liner AND the rear seat. There will be no aesthetic depreciation.

MAD_MIKE

Does this occur as a closed loop problem or just when hot?
Get the car warmed up, and when it starts idling funny turn the car off, and then restart the car. Does it run fine initially but after ~20 seconds does the car start to idle rough again? If the later is the case this is more likely a closed loop problem.
Have you checked your FITV? Check the write up in the FAQ.
Albeit there is junk on the fuel pump sock. When it is fully immersed the top half of the sock is clear and fuel flows easily, when the fuel level drops there is sediment or junk blocking fuel flow.
If you can beg/borrow(rent)/steal a fuel pressure gauge and attach it to the fuel rail you can see if there is a pressure drop. Check it when the tank is full, note pressure. And check again when the car begins to stall/sputter.
If the IACV is working normally and you have cleaned it check the FITV, Accord FAQ at the top of the forum.
Little? *snicker* Granted a Rocket powered B-bod Rivvy-Riv is no small car, but an CB Chassis Accord is not either.
There may be an air bubble trapped in the cooling system. Turn the heater control valve to full hot. On the intake manifold where the thermostat housing bolts to look for a bleeder nipple. Using a 12mm wrench crack it open and verify that it is a solid stream of coolant that comes out, if it sputters there is air trapped in the system which can play hell with how the car operates.

Shurt24

Thank you guys for responding.
Mike, thank you for taking the time that you did to break that mess apart and answer piece by piece.
I'll go through list and come back with results.
If push comes to shove (just because it seems like the most labor), I'll replace the screen filter/fuel pump.

Again, thank you all for your information, I'm going to take it and run with it.

MAD_MIKE

If the sock filter is filthy you will want to clean the gas tank out prior to installing the new pump/sock. If the tank is heavily corroded it may just be cheaper/easier to replace the tank. Cost is about $140 shipped from Rock Auto.

Shurt24

Well, I'm going to wake the dead post here.I admit, I really haven't messed with it much with my dad driving the car while I've been at school.

I start the car when it is cold, it revs to about 1100, and as it gets warm, the idle drops down to about 800 when it the car gets warm. It will idle at 800 as long as I do not touch the gas pedal. When it is warm and I touch the gas pedal, the idle drops lower to the point of dying. (haven't even moved the car at this point, just letting it run in neutral.) I restart the car, and it idles just fine until I touch the gas again.

I don't know if this helps, I'm just trying to give all the information that I can.

Fliptard

maybe need to adjust the idle.

1: Warm car up to operating temp, make sure fans come on at least once.

2: unplug the IACV

3: Turn the idle adj screw till your RPMs are about 800-1000ish. where it sounds like a good smooth idle.

4: Turn car off and unplug the ECU, Let the car FULLY cool down.

5: Plug IACV back in, then the ecu. Start the car and let it idle for awhile so it re-learns the idle.

94 accord typeR

^^^ that or it could be your TPS if your car has one (throttle position sensor) directly affects idle

accordturb96

mad mike what do you think about the evap system? Origal issue seems to do with fuel system and tank

Shurt24

Following Fliptard's procedure, except I pulled the ECU fuse instead of unplugging the ECU, if that will not work, then I will redo it tomorrow, (after somebody informs the newb {me} of where the ECU is on this thing) I am in the cool down stage. I will finish the procedure tomorrow and see what happens.

When I pulled the IACV plug, the car nearly died. After backing the idle screw out what seemed to be 2 or 3 FULL turns, it got to about 900 and sounded great. Is that normal to have to adjust the idle screw that far? I wouldn't be surprised if I started the car tomorrow and it wrapped up to 3K immediately. Seriously, all of this help is appreciated. Thank you guys in helping me learn.

holmesnmanny

This is incorrect. You want to set base idle from 500-600 rpms.

holmesnmanny

The car is supposed to sound like its going to die. You want base idle from 500-600 rpms. Keep in mind the first big line after 0 is 500 rpms not 200.

Just set it to 600 and youre good to go.

If you set it to 800 which will be as low as the idle will go then how is it supposed to idle at 750 which is normal non-load specs ?

It cant. Thats why you set it 600 and the ecu will bump it up to 750 or 820 depending on load.

Black R

Distributor cap and rotor button?

Easy to replace if those are the culprits.

Spark plugs too.

Shurt24

Whale, next up, is to retry the procedure using Holmesnanny's base idle recommendation.

Shurt24

Well, after setting it where I did with Fliptard's numbers, it seemed to work for a little but, but afterwards, it went back to doing it's extremely low idling/died once. By extremely low, I mean it once bounced down between 0-500. Then it tried really hard to sit at 600. So I think if I set the base idle around there (which I'm going to do either way, for testing purposes) It'll start letting the car do what it wants.

To be continued.

Shurt24

I go back outside to begin resetting the base idle (again) and as I unplug the IACV (the car dies) I notice the adjust screw is screwed all the way back in. Like it's screwing itself in while driving?

Shurt24

New thought.

Combination of bad base idle AND dirty fuel sock? Makes sense to me.

holmesnmanny

Its not a recommendation. Its straight out of the helms.

If you think its a fuel issue, get a fuel pressure tester from harbor freight. See what the fuel pressure is actually doing.

Shurt24

Ah. Okay. I wasn't questioning it. Thank you.

I'll see what I can do about checking the fuel pressure. Are there any helms' measurements of that fuel pressure should be at operating temperature?

Shurt24

Ah. Okay. I wasn't questioning it. Thank you.

I'll see what I can do about checking the fuel pressure. Are there any helms' measurements of what fuel pressure should be at operating temperature?

holmesnmanny

35-45 with the vacuum hose connected and it will be around 5-10 higher with it disconnected

Shurt24

I haven't checked the fuel pressure yet, but I did take some sewing thread and wrap it around my idle adjustment screw (opposite the way the screw turns) and set the idle that way........it hasn't died on me since. It seems that the motor was vibrating so bad (or just my driving) [probably a bad rear motor mount] that it would screw the idle adjustment screw all the way in to where it wouldn't idle when warm. I don't know if that makes sense or not, but driving this thing is a breeze again when I don't have to feather the gas at every stop.

holmesnmanny

There's an oring that goes around the idle screw. I suppose you could be missing yours. You can pull another screw from the junkyard.

I'm not really sure I even know what it is you're saying though.

Shurt24

No no, your response indicates you figured it out. Lol. The idle adjustment screw of mine did NOT have an O-ring on it when I pulled it out. That would explain why it was so easy to adjust itself.