|
|
|
|
| Author |
|
|
Writer/Teacher
|
high idle when very hot out
I haven't posted about this "problem" before because it happens so infrequently, but when it is very hot and humid out (88 degrees or hotter), once my 951 is warmed up the idle occasionally will not drop below 2K. It will do this at a few stop lights, but then will end up dropping back down to around 1K.
This problem does not occur at all when it is less than 85 degrees out. Am I looking at some kind of temp sensor?
__________________
Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
||
08-31-2007, 02:45 PM
|
|
|
Registered
Join Date: Jan 2007
Location: San Antonio
Posts: 462
|
same prob here, mine idles high enough to drive itself around,but only when hot, gets about 1600 rpms, its kinda like a cruise control,
__________________
1987 944 n/a |
||
|
08-31-2007, 08:36 PM
|
|
|
Writer/Teacher
|
bump
__________________
Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
||
|
09-01-2007, 06:19 AM
|
|
|
Registered
|
CJ i had a similar problem with my NA, im not sure exactly what it was but it did go away after that big project i did last winter. I think one of the few things it could have been was
1) DME temp sensor 2) ISV It was similar to yours, i would come up to a stop sign or such, the idle would just sorta hover around 2K for a little while then really really slowly come back down. the problem was very infrequent. but i havent seen it since...
__________________
1995 993 C2 |
||
|
09-01-2007, 06:30 AM
|
|
|
winter-hater club member
Join Date: Oct 2003
Location: salt lake city, utah
Posts: 24,705
|
mine does this also, but it has to be closer to 105F outside. it'll creep up to about 1500, slowly come down, repeat.
__________________
2000 Corvette - ????, 2007 Buell XB9R - Astrid, 1996 Discovery - Piglet, 2000 Forester "COOL PRIUS!" - Nobody Ever |
||
|
09-01-2007, 07:59 AM
|
|
|
Registered
Join Date: Jul 2007
Location: new york
Posts: 209
|
My dads 951 does the same thing qhen hot. It goes up to like 2k rpm. Haven't fix it though.
__________________
 1986 PORSCHE 951 3.0 project has begun!1989 IROC-Z(Show Car) 1961 Willys Jeep w/ 283 chevy(straight open headers) 1995 Dodge Ram 2500 HD 1981 Corvette 4spd |
||
|
09-01-2007, 08:23 AM
|
|
|
|
Writer/Teacher
|
I'm thinking it must be a temp sensor, but today when I had some free time before work, I cleaned all the electrical connections for the throttle body and flow meters, just in case.
__________________
Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
||
|
09-01-2007, 11:18 AM
|
|
|
Politically Incorrect
Join Date: Aug 2005
Location: Hoover, Alabama
Posts: 1,494
|
Just throwing things out here:
- heat soak related vacuum leak (I don't recall your mention about changing any lines since you bought "Ruby") - does the throttle fully return to the stop when this happens - is the TPS adjusted correctly PS: 88 deg F is hot? It was over 100 here for about three weeks! Of course I was in CT during this southeast heatwave and enjoyed temperatures that averaged 5-10 deg cooler than normal.
__________________
Edek '87 924S '91 535i |
||
|
09-01-2007, 01:01 PM
|
|
|
Writer/Teacher
|
It may be unrelated, but I advise everyone who has this problem to do the following:
Yesterday I swapped out a bad cruise control motor for a "new" one. When I got it back together I took the car for a drive, and once it got to standard operating temp, the idle climbed to 2K - in other words, the problem reoccurred, despite it not being incredibly hot out yesterday (around 84 or 85). I got back under the hood and loosened the throttle cable that attaches to the cruise control motor. Problem solved. I guess I won't know if this was the culprit unless we have any more 90 degree days this year (getting unliklier by the day), but it's worth a try 
__________________
Current Stable: Black 07 Porsche 987 Cayman S: Long-Tube Headers; FabSpeed Exhaust; VividRacing ECU Tune; IPD Plenum; 997GT3 Throttle Body. Blue 1983 Porsche 928S. 1985.5 Porsche 944 Rat Rod. 2011 Acura MDX. 2008 Mazda 3. Gone But Not Forgotten:Garnet Red 86 Porsche 951("The Purple Pig"). Alpine White 83 Porsche 944 ("Alpine Wolf"). Guards Red 84 Porsche 944. |
||
|
09-02-2007, 11:00 AM
|
|
2007 Porsche Cayman S
The Viridian Falcon
SOLD! -- The Purple Pig
SOLD! -- Mighty Mouse
SOLD!! -- Alpine Wolf
993 C2
