You guys with the surging idle problem, I just discovered something that may be useful to check.

I just realized that if my engine isnt surging then it will start surging up and down immediately when the cooling fan comes on. After the cooling fan turns off it may stop surging after 15-30 seconds, but sometimes it may continue to surge until I steadily give it more gas and back off until it stops....once it stops it will immediately start surging then again once the cooling fan comes back on.

You guys with this problem, do me a favor. Let your car cool down, open your hood, start you car and just stand there until the cooling fan comes on and tell me if your engine starts surging up and down.

What all sensors are linked to the cooling fan? There is a coolant temp sensor, a thermoswitch, and another one or two isnt there?

 

OK, I had to do this!

I recorded the surging problem. It is a 15 meg zip file if anyone want to download it.

If you watch from the beginning you will see that the primary cooling fan is stationary and the engine is idling normally, at the moment the primary fan turns on the engine begins to surge erratically, I then count to 18 seconds and the engine returns to normal.

http://63.144.16.232/honda-tech/enginesurge.zip


[Modified by CaNaBiS, 10:17 PM 9/24/2002]


[Modified by CaNaBiS, 11:05 PM 9/24/2002]

 

If it's on the edge it will start at any engine/electrical load. Usually it's the A/C compressor that triggers it.

 

Is there a post as to why you're having the surging problem? It may help to check you're fast idle thermal valve. Even without the tb coolant bypass, some valves get loose inside.........

 

Mine is the other way around. at idle, Surges, fan turns on, surges stops, fan turns off,surges. Or at idle, headlights off, surges, headlights on, surges stops.

 

I swapped out the fast idle valve...still does it. What else could it be?

 

cant download your file..

 

Sorry,

http://63.144.16.232/browsable/honda...nginesurge.zip

 

yep, my car does the same thing....though now it only surges with the head lights on....

 

My car does this as well, did it last night after racing a damn Cougar...guy wouldn't leave me alone. My car through lights earlier that day, so I had to reset my ECU, seems to do this the next couple days, after I reset. anyone more info would help, cuz this can get annoying, everyone thinks you have a damn vacum leak..

D
97SH

 

Yeah, I know. Its no vacuum leak. I wish there was a more concrete way to nail down what is actually causing this!

 

did you try taking off your intake and puting your finger over the hole where the fast idle thermo valve is? i hear that if you block ths hole off and it stops it is the fast idle thermo valve, maybe the one you replaced it with needs adjusting or somthing because that valve moves coolent through it so it sorta makes sense with the other symptoms

 

I dont understand exactly what you mean. Take what off? The intake? Cant do that! The engine wouldnt run!
You mean take the coolant line off of the fast idle valve and plug it? There was a thread on how to bypass the fast idle valve....if I could only find it.

 

If you remove the intake tubing pre-tb, there are 2 holes for idling, the iac and fitv. You could cover one to see if the surging goes away, I think it is the lower one. Also, have you checked if your idle screw is set correctly? If you unplug the iac valve, the car should idle normally when warmed to normal operating temps.

 

 

Its not the fast idle valve. I have replaced mine with 3 differant ones and it does the same thing. And its not the throttle body, I switched that out also.All new vacuum lines,surges still. Cleaned the IAC, still surges. I know if you turn the idle screw all the way in and one full turn back out, it does not surge,but the idle is rougher. IMHO

 

A rough idle can be traced back to a bad charging system too, have you checked you alternator and battery. It could be dirty injectors too


[Modified by JDMET-2, 12:37 AM 9/26/2002]

 

I dont know of you have covered this but if you have a air pocket in your coolant it will do the same thing you are describing.You can bleed the coolant with a valve down and to the front of the TB.If you have ruled this out already sorry.

 

Im having an idle problem as well, i thought i had fixed it ere 2 days ago

https://honda-tech.com/zerothread?id=294069

it ran fine in under any kind of driving and then last night the bad idle returned.
i guess all my idle sensors are going bad i dont know what to check next. My FIV was the original culprit im assuming but now as its blocked off i dont know.




[Modified by ArchAngel Sabastian, 1:31 PM 10/2/2002]

 

OK GUYS, I THINK I GOT U ON THIS ONE!!!!!!!!!!!!
does ur car hesitate when u gas it? my car was doing just the same as all of u + it would hesitate briefly when i would gas it... after trying many things.. it all boiled down to my distributor... have u all replaced parts in ur dist at one time or another..?.. if so this could be the problem...

my rotor ended up getting turned 180* on the dist shaft... that was in turn causing my idle to be a little messed up.. could not get it to go smooth.. it would bounce around for a while then even out.. but hesitate when i gas it... we then figured out my dist was 180* off.. turned it.. and set the timing agen.. now it runs like a champ... i messed with the idle screw.. fast idle valve. all that stuff.. none of it helped.. it was my distributor...
hope that helps u guys...

 

i dont have the hesitation problem..


CaNaBiS i cant see your IAC pic or get the link to the vid to work.


[Modified by ArchAngel Sabastian, 2:05 PM 10/2/2002]

 

The rotor can only go on one way. How did you put it on wrong?

 

yeah isn't there like a notch/flat piece that only allows it to go on one way?

 

I unbolted the IAC from my car and the two "screen" areas that im assuming let the air pass into the IM are heavily gunked what can i use to clean it ?

i found it, carb/TB cleaner. i think ill remove the Coolant lines from this while im at it.


[Modified by ArchAngel Sabastian, 2:47 PM 10/2/2002]

 

ok ok, i know this is old, but i thought i'd put this back up top:

I've done the coolant bypass so i can block off the fast idle valve, and i've purged the coolant system, i guess next is the cleaning of the IAC.

I guess i can adjust the idle screw, but on my TB it has a yellow "tab" of paint where the screw shoudl be lined up.

anyone have anymore ideas? pcv? after year of surging and bouncing its starting to get annoying. I really thought cleaning the IM, and TB and blocking off the fast idle valve would do it, but i guess not