Engine Idle Problem

[Cesarfl]

I just went out for a nice Cuban cofee, hit the Dolphin expressway and ran the car to 6500 rpm on 2nd, 3rd and dropped down to cruising, all of the sudden the car starts idling from 750 rpm to 2000 rpm all by itself, drove back home still doing it in cicles every two or three it stays at 2000rpm, is a 99 C2 with 63,000 miles, cold air intake, Fabspeed headers and mufflers, never had this issue before, any help.

Thanks

[jinijazz]

I'm not an expert on this, but I had the exactly same experience with my 99 Boxster.

After replacing MAF sensor, it became normal for 2months or so but finally the engine got blown off.

Sorry for replying with the worst case scenario, but I really hope no one has to go through my experience again. Check with reputable Porsche service, do not ignore it even if it seems back to normal.

[1999Porsche911]

In addition to cleaning the MAF, remove the idle control valve (ICV) from the left side of the throttlebody and clean it with carb cleaner. Also check all vacuum lines and intake connections and make sure they are connected and tight.

[Izzy]

Cesar,

Cafe cubano y un pastelito the guayaba siempre me da el mismo resultado. And I do miss it in the Carolinas.

I had a very similar situation, when you mentioned idle between 750 and 2000 rpm, you mean at speed or just idling? My 99 was doing it at idle, and cleaning the MAF and valve did the trick. A few thousand miles later I replaced the MAF (around 60 K) since it was throwing a code. Now it has been perfect for 4K miles. Can be an inexpensive test just to clean it and see the response.

Also, don't forget to see if you got any codes being stored that can help you get pinpoint the issue. Codes could be there even though you don't have a CEL. If you don't have a code reader, most "Pep-boys" type of auto stores will lend you one to use in their parking lot.

[Cesarfl]

I just connected my Durametric tool and the following codes PO446, Evap Canister Shut Valve and PO 506 Idle air control engine speed too low.

Shoul I proceed with a cleaning of the MAF and the IVC

Thanks

[Izzy]

It can't hurt. But looks like the main problem is elsewhere. Do a search for the Evap canister, there is a good bit of information here about problems and locations.

[1999Porsche911]

I just connected my Durametric tool and the following codes PO446, Evap Canister Shut Valve and PO 506 Idle air control engine speed too low.

Shoul I proceed with a cleaning of the MAF and the IVC

Thanks

The P0446 indicates that you evap canister purge line is blocked, but sometimes this is a false fault. the P0506 indicates that your ICV is stuck in the open position and needs cleaning or replacement.

I would remove ICV and clean it, checking that the valve moves freely. Reset computer and see what happens.

Edited December 5, 2006 by 1999Porsche911

[Cesarfl]

Does anyone ahve a picture of the ICV I am not sure

[Loren]

Does anyone ahve a picture of the ICV I am not sure

http://www.renntech.org/forums/index.php?s...ost&p=45536

Item 7 in the diagram.

[Cesarfl]

Thanks Loren, this website pays for itself all the time, I hope verybody here is contributing to keep it going and healthy

[Cesarfl]

Well I just finished cleaning the MAF , and the ICV, car still at over 1500 rpm's drove back to the turnpike and ran the hell out of the the car, nice 6000-7000 rpm shifts, baby now is running smooth as silk I guess the cleaning did the job for now. Thanks to Izzi, Loren and friends, you guys just save me a ton of money and I don't even work for Geico.

[Izzy]

Keep an eye out for MAF specials from Sunset, you could be due soon for a new one and better to get it on sale. Just click on their link and it should come up.

And don't run over the gators, they are protected species.....

[Loren]

:thumbup:

[aracerx]

:thumbup:

This situation is perfect example of why I (in the business?) actually enjoy renntech more than ANY other site. Just as importantly, and a little "nice" strange is that THERE IS NEVER MUCH MALCONTENTS on here...as most of us are aware...other "sites" seem to harbor nasty people who always have a comment!

Loren and Co.-(you guys) are the best! Mark

[PrinciPorsche]

I'm new, so I haven't seen the extent of the board quite yet, but yes, just helpful sorts with no attitude.

Refreshing!