JaysAccord94

I have a 1994 honda accord dx. when i start the car it will idle solid at around 3000rpms then after a minute or two the car will begin to surge between 1000 to 3000rpms, after the car seems to warm up (about another 3 or 4 minutes) the engine idles normally. any ideas....i have cleaned the iacv and replaced the fitv. thanks

P_Adams

As in all cases of this type, make sure you have no air in the coolant system.
The FITV requires a good engine temp thermal sourse and the cooling system is it. If a bubble of air should form under it, it would delay any engine heat from reaching it. Raise the nose of the car and purge the system.

P

ALLDATAdiy INFO

Another possibility is the Idle air control Valve, or the MAP sensor. Both of these will cause irregular Idle Problems. Is your check engine light on? Have you pulled any codes?

I attached a picture showing you where the MAP sensor is on your car.

JaysAccord94

if there is air in the coolant system, isn't there a bleeder to let air out(if so how do i do this). and what do you mean by purge the system.

ALLDATAdiy INFO

Sure is ALLDATAdiy shows it here in the picture:

JaysAccord94

now do i just jack the car up and bleed it until ir comes out. i was told once that there is a bleeder on the top of the engine.

ALLDATAdiy INFO

This is the procedure given on ALLDATAdiy

ENGINE COOLANT REFILLING AND BLEEDING
Ensure relay box lid is shut when pouring engine coolant to avoid damage to electrical parts.
For best protection, mix anti-freeze with an equal amount of water (50 percent concentration) in a clean container prior to starting the bleeding procedure.

1. Set heater temperature lever to maximum heat.

2.When radiator is cool, remove radiator cap and drain plug, then drain cooling system.

3.Install radiator drain plug and tighten securely.

4.Remove, drain and reinstall coolant reservoir.

5.Fill reservoir to MAX mark with coolant mixture.

6.Loosen air bleed bolt in water outlet, then fill radiator to bottom of filler neck with coolant mixture.

7.Tighten bleed bolt to specifications as soon as coolant starts to runout in a steady stream without bubbles.

8.With radiator cap off, start engine and allow cooling fan to cycle twice.
If necessary, add more coolant mixture to keep coolant level at bottom of filler neck.

9.Install radiator cap and check cooling system for leaks.

billyrusa

The bleed bolt is located in the thermostat housing. You can find it by tracing the low radiator hose to the engine.

1. Drain the coolant by loosing the drian plug on the bottom of the radiator. Use a clean container to receive the coolant if you want to refill the coolant.
2. Loosen the air bleed bolt in the thermostat housing, then fill the coolant.
3. Tighten the bleed bolt as soon as coolant starts to run out in a steady stream without bubbles.
4. With the radiator cap off, start the engine and let it run until warmed up.
5. Add more coolant to the radiator to make it full.

palacios

First time poster here. So on my 93 Accord, I had a mechanic in Mexico swap out the IACV with one from a junk yard because the idle would go crazy when the engine was cold. Once the engine was warm there was no surging. Anyway, he changed that out but then it started doing the whole crazy surge thing when the engine was warm. I didn't have any more time or money for a less-than-stellar mechanic to troubleshoot the problem so I took the vehicle as it was. The car works great and it made it all the way home to Utah. Once I got home and started looking into the problem a little more, I noticed that when I start the car for the first time of the day, the engine would idle at about 1700 RPMs but if I go into Reverse or Drive without letting the engine warm up to normal operating temperature, the engine RPMs would surge between 200-500 and the car would shake like crazy and occasionally stall if I didn't give it some gas. The car was also surging between 500-1700 RPMs when the engine was at normal operating temperature going from Drive to Park. I found and followed the advise from this forum and removed and cleaned the TB, IACV, FITV (also tightened valve). It seemed like after I cleaned those components the car started working much better but after a couple of days, I noticed the surge again but only with a warm engine going from Drive to Park. Apparently, I didn't bleed the coolant system well enough because after I re-bled it the problem went away. Now, about a month later, I am now getting the exact same problem. I should add that my center and rear mufflers have rusted through and exhaust is coming out from more than just the rear tail pipe. I have no clue if this would cause the surging problem. Anyway, lately I have been getting the 200-500 RMP surge with occasional stall on cold engine going from Park to Reverse or Drive and the surge on warm engine going from Drive to Park. The warm idle is not as bad as it was before and only happens for maybe 2 seconds immediately following the gear change. I am going to try bleeding the cooling system again but I have no clue what to do about the cold idle surge. Like I said, most of the TB components have been removed and cleaned, so I'm guessing my next move will be another component replacement. I also adjusted the idle screw just enough to keep the engine from stalling during the cold surge. Is there anything else I can do to fix this?

stpeteshorty

I JUST fixed this problem in my 94 EX.. I suggest you try this
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/

This is the write up I used to fix my problem. I replaced the IACV a month ago with little to no change, the this weekend we took the FITV out and sure enough it was all the way out. Tightened it up and voila! No more surge... not even a little :D

palacios

stpeteshorty,
Thanks for the reply but I also followed the same write-up last month and it didn't really help my situation. I got maybe one turn on the FITV and I didn't really notice any improvements in my idle. If anybody else has any helpful suggestions, I would greatly appreciate them.

stpeteshorty

Even cleaning it didn't help?

What about the IACV? Did you try cleaning or bypassing the IACV to see if there was an improvement?

palacios

I cleaned the Throttle body around the butterfly area. I completely removed the IACV and FITV and cleaned them both with B-12 carb cleaner. I also tightened the FITV and no significant improvements occurred. The IACV was changed in December with a junk car part. I have not tried to bypass the IACV because I didn't know we could even do that. What do I need to do and what am I looking for? I re-burped the coolant again after my original post and the warm idle surge has disappeared for now. Right now all I'm dealing with is my car shaking and wanting to die when I start it for the first time in the morning but only after shifting into R or D. After looking at it again, it looks like that surge is actually between 400-700 RPMs not 200-300 as previously stated. Any help is appreciated.

Turbowa

If its idling to low there is an adjustment screw on the top of the TB. You may need to screw it in some to raise your idle.

palacios

I already did that. That's basically what's been keeping if from dying lately. As it is right now, my idle with a cold engine on neutral is about 1700 RPM. Once the engine is warm the idle stays at 850 RPM. The problem is, I normally don't give the engine enough time to warm up before I take off and I normally drive off after the car has been on less than 30 seconds. When I do that in the morning, as soon as I shift into R or D, the RPM will drop from 1700 to about 400 then continuously flux between there and 700 RPM. Sometimes it does that but stays on and sometime it just turns off. After I adjusted the throttle screw I experienced less stalling but it still happens occasionally. I don't want to turn it up any more since the normal warm idle is supposed to be 750 and I'm already at 850.

stpeteshorty

hm.
There are so many things that can contribute. Timing could be off for one... vacuum leak can mess up the idle too. Unfortunately it's going to continue as a game of emilination until you get it figured out
After each attempt have you reset the ECU? Have you checked the coolant again? If it's too low it can cause the same reaction as the IACV.

I'm not 100% sure of how to bypass the IACV... I just know it can be done. You can even just unplug it (I think... I own a Civic but it should be the same general idea).

sxm5369

i had this same issue last year, and i cleaned the FITV and IACV and still the same problem, it ended up being that i had a gasket leak on my intake manifold. hope this helps