Rejckt

iTrader: (2)

While driving normally on any gear, everytime as I approach a redlight or slow down drastically, I put the car into neutral. Now I normally idle at around 700-800rpms, I notice that once I step on the clutch the rpms will sometimes drop down to 200rpms or around that nature. I'm not sure if it's the IAC valve or not. Anyone one have any inputs on this?

assclown

iTrader: (1)

tried taking it off and cleaning it? a new one is at least $150 iirc

Rejckt

iTrader: (2)

Tried cleaning it, even purchased a new one for $150 but after installing it. The rpms jumped up and down. Now returning it.

assclown

iTrader: (1)

vacuum leaks?

Rejckt

iTrader: (2)

Maybe, but unlikely. Is the rear motor mount vac assisted? (cls6 mount that is)

assclown

iTrader: (1)

not sure, haven't ordered my mounts yet. kris should know

notbrant

iTrader: (2)

My car was doing this after I reset ECU and immediately revved up engine after cleaning out my upper IM and EGR port, I think it learned that it was getting a lot of air right off the bat, so I disconnected battery again and let it idle for about 10 mins before starting to drive again and the problem went away. Hope this helps.

Rejckt

iTrader: (2)

I have reset the ECU many times from since this started happening in the winter, I think I'm going to do the 7year/100k , and just waste the money changing the IAC and praying it will fix. But I don't know what else could be the problem.

zeta

iTrader: (1)

IIRC, you are swapped and S/C'ed?

My car (CLS-6 S/C'ed) does this occasionally; however, it only does it when it is extremely hot out (FL summer heat, stop/start traffic = high underhood temps.) down here.

The CLS Helms has the ECM/PCM Idle Learn Procedure:

The idle learn pricedure must be done so the ECM/PCM can learn the engine idle charateristics. Do the idle learn procedure whenever you do any of these actions:

Reset the ECM/PCM.

NOTE: Erasing DTCs with the Honda PGM Tester does not require you to do the idle learn procedure.

Remove the battery or disconnect its terminals.
Remove the ECM/PCM or disconnect its connectors.
Remove the driver's or passenger's under-dash fuse/relay box.
Remove the BATTERY (120A) fuse from the underhood fuse/relay box.
Remove the BACK-UP, ACC (40A) fuse from the under hood fuse/relay box.
Remove the No. 13 CLOCK, BACKUP (15A) fuse from the passenger's under-dash fuse/relay box.
Remove the PGM-FI main relay.
Disconnect the starter cable terminal from the underhood fuse/relay box.
Disconnect the connectors between the engine wire harness and the left engine compartment wire harness.
Disconnect the connectors between dashboard wire harness A and dashboard wire harness B.
Disconnect the ground terminals, G1, G2, G11, and G102.

To complete the idle learn procedure, do this:
1. Make sure all electrical items (A/C, audio, rear window defogger, lights, etc.,) are off.
2. Start engine, and hold it at 3,000 rpm with no load (in Park/neutral) until the radiator fan comes on, or until engine coolant temp. reaches 194f.
3. Let the engine idle for about 5 minutes with the throttle closed.
NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.

That is what the Helms (Section: Idle Control System; pg. 11-170) states; however, when I perform the idle relearn procedure, I make sure that all electrical stuff is off, start the car and let it idle through 3 fan cycles. Never had a problem doing it that way.

Also, if you are swapped, it might be a good idea to check all of the harness connections and such to make sure they are fully seated and waterproof. Just a thought.

Rejckt

iTrader: (2)

^--- Yeah man 6spd and s/c. I've notice that it stalls more when it gets ridiculously hot as well.

My car gets HOTT under the hood.

assclown

iTrader: (1)

mine will get hotter

Rejckt

iTrader: (2)

sometimes, the coolant disappears...

assclown

iTrader: (1)

i will be taking my engine exhaust to spin a turbine to compress intake air and force it into the throttle body

notbrant

iTrader: (2)

Saw this posted on another forum...maybe it will provide some insight?

It's actually blower surge. This is caused by the supercharger's vacuum signal to the power valve not being the actual engine vacuum, but the vacuum created by the supercharger. The power valve reads the higher vacuum created by the supercharger, this vacuum closes the power valve, causing the fuel mixture to go lean, the engine then slows down due to the lean air/fuel mixture, so the vacuum signal from the supercharger causes the power valve to open as the supercharger's vacuum drops, so again the engine speeds up due to the richer air/fuel mixture, rolling from rich to lean, causing the engine to speed up and then slow down.

Rejckt

iTrader: (2)

You may be right notbrant, my afr does go to 21.7 when I let off gas... but I can also dump more fuel on the decel too and this only started happening recently. I've been s/c'd for over a year now.

zeta

iTrader: (1)

Very interesting. By force of habit, I usually blip the throttle when down shifting or coming to a fast stop and it does not happen. Sometimes I forget (to blip the throttle) though and it does not happen either.