Hi All,
First of all I am a newbie and would like to say to mods thanks for having a place where Honda ownwers can help and feed from each other. Thanks again.
I have searched and found alot of threads on the topic of idle surge, however mine is unique...
I have a 96 Accord EX 2.2L VTEC, at start up I am having a surger at idle, CEL code is P1508, I have taken of the IAC and replaced with new one, I also have replaced the FITV underneath the throttle body, and also EGR valve, bled system and still to no avail. I removed the intake completely and cleaned out with throttle plate cleaner and carb cleaner. I also had a mechanic from Honda come to my house and try to diagnose the prob, and could still not figure it out. He sais that from what I have done it should have corrected the prob.
Can you guys tell me what you think? Thanks

 

Im assuming you reset the ecu to clear the code. Everything is plugged in correctly? If you know the new IACV is not faulty I would suspect a short in the wiring. Im on my phone right now so i can't check but I would imagine the service manual tells how to check the IACV connector and ecu pins to look for a short.

 

I had a leaking intake manifold gasket that gave me the same issues.
Replaced it and haven't had an issue since.
A vacuum leak on any part of the manifold could cause your symptoms.

 

^2x on that, broken vacuum lines, faulty wiring, bad gaskets, clogged EGR ports ect.

have you looked into checking the condition of the EVAP canister/syster bellow the cruise control? just a thought

good luck!

 

Thanks guys for the replies,
Well yes, I have reset codes, and each time I reset, the CEL comes back on within h30 secondshere is all I've done:
Checked for vacum leaks all over, replaced the IAC valve twice, replaced the FITV valve, replaced the EGR valve, replaced the MAP sensor, today I changed the throttle body and put one from another car to see if my throttle body was bad, still have the same thing.
I bought this car with this problem and was told it was the IAC valve, I have put two new ones.
I'm wondering if someone might have swapped out the head and installed a VTEC head, there should be a pressure switch under the distributor on the head and it's not there, there is a plug in it's place. However, there is also no connector anywhere near or around that would have plugged into that pressure switch. Does anyone out there have a pic of exactly what the engine bay should look like? What color wires are on the connector for IAC, Air Temp sendor?
1996 Accord EX 4dr leather automatic with 2.2L VTEC F22B1
Thanks again guys.

 

Man, I know this is so simple, but I just can't figure it out.

 

Does the symptom stop at any point?

 

No, from the moment you turn it on, whether it's cold or hot, she has that surging idle.

 

Sounds like a vacuum leak somewhere! With the engine running, take a can of throttle body/carb cleaner/breakclean and lightly spray it around any gasket area and vacuum hose on the intake manifold. If you hear a change in idle rpm you found your leak.

 

Yeah, I've done that, several times, I even replaced both intake manifold gaskets.
I can't find, nor do I hear a leak.
I'm thinking about blocking all the vacum hoses, and then start the engine and then start unblocking them one at a time to see if I can narrow down what part is malfunctioning. What are the chances that one of my vacum hoses is routed incorrectly and is adding pressure as opposed to pulling vacum, you know working in reverse? I don't know just running things thru my head right now......

 

Pinch them with pliers. Leaking PCV valves can cause surging.

 

I'll give it another shot tomorrow. I'll give an update after, Thanks guys.

 

We I checked very thoughly for a vacum leak, went from hose to hose very slowly spraying carb cleaner throughout the entire hose from end to end on all hoses, intake manifold seams, egr seams pcv valve seams, IAC valve seams, fast idle thermo valve seams, MAP sensor and TPC seams and entire throttle body. I can definately say with out a doubght that I do not have a vacum leak.
Still have the surge.

There is a 97 accord at my job non VTEC that I looked at just to make sure that all my vacum lines are in the right order, funny thing is that most of the vacum lines are no even hooked up, and I started it up and no CEL and no idle hunting or surging at all....

IDK?

 

Well I finally concluded that my ECM is not communicating with the IAC, I have a new IAC valve, and the circuit to the IAC from ECM is good, I possitively have no vacum leaks. I have ordered a ECM and should have it bay the end of the week. I'll keep you guys posted. Thanks again to all on this thread who shared their input.

 

Well here's an update on my Accord. It turns out the prob was in the ECM. I ordered one on Ebay, and while I was waiting for it to arrive, I opened up the panels on the one in my car. I found that the terminals on the cirquit board had corrosion on some of them and there are two cards, similar to computer memory cards that had rust on the terminals that were soldered to the board.
When the one I ordered arrived, I opened it up just to see what I would find, and the board and all terminals were like new. I plugged it in and grounded it started the car and, WHALA!! No CEL and the car ran perfect.
So anyway, just a helpful tip, If you get this prob, GOD forbid, Clean your IAC, check for Vacum leaks, but before you spend $$'s on a new IAC, check your ECM. The IAC valve costs me $208, The Fast Idle Thermo Valve cost me $75, the ECM only cost me $40 on Ebay shipped.

Thanks for all of you guys help, now at least I know whem my IAC and FATV valves were replaced.
I am very happy now.

 

Thanks for the update. That information will undoubtedly be quite useful to others.