jgcox6

93 that idles down at 500rpm or lower when it is put in drive. It doesn't jump around when in park..it just drops when it is engaged in a gear..I have gone through procedures for checking the IAC and FITV and they check good..the procedure says that it is possibly the air boost valve....ordered one and waiting to see..but in the mean time...what do I next...? What can I check??

CrossCountryAccord

i'm assuming this is an auto tranny?

JimBlake

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jgcox6 &raquo;</TD></TR><TR><TD CLASS="quote">...what do I next...? What can I check?? </TD></TR></TABLE>
Try adjusting your 'base' idle speed.

jgcox6

It is an auto tranny,, and I have adjusted the idle speed...but to get it to not fall below 500rpm...I have to set the base idle too fast..and with the IAC plugged in it idles at like 1200rpm.. It does just sit at idle fine..no fluctuations at all....just when it goes in gear...I printed out a flow chart from autozone and it mentions something about the A/T shift position signal.???

jgcox6

Jim, I have increased the base idle speed and when it is at regular idle it is like 1200rpms! I would like to get it fixed instead of mal-adjusting the idle and idle at 1200rpms. As i mentioned earlier,,,a procedure put out by honda basically eliminated the IAC and the FITV...and the only thing left was the Air boost...I am going today and get the part and put it on...if that doesn't work..what do i do next? I don't have a clue....

JimBlake

I was just thinking that if the base idle is set wrong, the IACV can sometimes compensate during a steady idle without loads. But then it doesn't handle very well when loads are switched on & off. Drag of the torque converter being one of the biggest loads that an idling engine will see.

Base idle can get all screwed up by trying to adjust it with any of these things:
- if the throttle cable doesn't let the throttle close all the way
- if the throttle's mechanical stop doesn't let it close all the way
- if the throttlebody bore is cruddy
- if the FITV isn't closed (warmed up) properly)
- if you adjust the idle air bleed screw while the IACV is active (plugged in)
- vacuum leaks

The tranny shift position signal is important because in gear, the drag of the torque converter is huge. The ECU needs to know so it can compensate. I haven't had to mess with the air boost valve, but I have a feeling it's got a lot to do with compensating for the load of the T-C. (Newer cars seem to have the function of the air boost valve, built into the newer versions of the IACV).

jgcox6

So based on what you are saying...its quite possible to be the air boost valve? I have looked and listened for vacuum leaks and believe I am ok there. I will let ya know at the end of the weekend.