FIV not interchangeable between automatics and manuals?

[Shehzada]

I have been trying to solve my hunting idle problem for over 3 weeks now. I cleaned the IACV and then tightened the FIV, with no good results. The idle fluctuates between 1K and 2K. I even opened the coolant bleeder screw and verified that it was streaming smoothly with no bubbles.

So I finally found a new Honda FIV ($49) and bolted it up, but it made my idle worse. It turned out mine was made for 90-93 Automatics not 5-Speeds. Are they made that different? I guess I will take apart my IACV again since I can't afford a new one (my dealer wants $280). Is there a plunger inside the IACV?

[blackice]

This sounds exactly what happened to me. I ended up replacing both the fitv and iacv. Don't take the iacv apart, the little section the antifreeze flows through has nothing in it...I did that and f'd up the seal. Check your tps voltage yet? Also have you bled the radiator fluid to get the bubbles out? Vacuum leaks will also cause idle hunting, check your throttle body and intake manifold gaskets by spraying intake cleaner or something around them and see if the idle changes. Might also try cleaning the egr valve. I finally solved my issue (replaced those two parts, bled radiator, blocked egr off, checked all vac lines) by adjusting the idle to spec (750-850). I had done that before but I went and bought an aftermarket tach. The stock tach was off by almost 400rpm so i had been idling at around 1200. Anyway that cured the problem. Hope that helps.

[Shehzada]

This sounds exactly what happened to me. I ended up replacing both the fitv and iacv. Don't take the iacv apart, the little section the antifreeze flows through has nothing in it...I did that and f'd up the seal. Check your tps voltage yet? Also have you bled the radiator fluid to get the bubbles out? Vacuum leaks will also cause idle hunting, check your throttle body and intake manifold gaskets by spraying intake cleaner or something around them and see if the idle changes. Might also try cleaning the egr valve. I finally solved my issue (replaced those two parts, bled radiator, blocked egr off, checked all vac lines) by adjusting the idle to spec (750-850). I had done that before but I went and bought an aftermarket tach. The stock tach was off by almost 400rpm so i had been idling at around 1200. Anyway that cured the problem. Hope that helps.

That's so funny. I also took the IACV apart and broke that seal too. I had to go out and get some high-temp rtv to seal it back up again. When you replaced the FITV and IACV..........did you install new ones or got used junkyard ones?

[blackice]

I installed new ones...cost me an arm and a leg off majestic honda lol. Dunno if I would trust used ones...worth a try if you find em cheap. What else have you checked besides those two parts?

[Shehzada]

I installed new ones...cost me an arm and a leg off majestic honda lol. Dunno if I would trust used ones...worth a try if you find em cheap. What else have you checked besides those two parts?

I opened up the coolant bleeder screw but no bubbles came out.......only steady stream of fluid. That's about it. It seams like Majestic IS is the cheapest dealer out there.