924Board.org

[Fasteddie313]

on cold start it hasn't been revving past like 3k well (stumbled) until it was 3/4ish way to operating temp.. then it would pull wonderfully..

today I got it running, idled it for some time through all gears and changes the trans fluid to redline mt90.. it ran as good as ive ever sceen it up there today.. looked perfect...

I put it down and it started and ran just fine, well kinda I suppose, still cold startish doesn't want to rev past 3k much at first...

I took it like a half mile in a loop and it warmed up and ran great...

then I took it out on a bit further adventure..

a ways up the road, I thought the throttle stuck open a bit, I pulled over and checked the TB, one of those butterfly stops had wiggled its way loose and I corrected it thinking it was the problem..

I started it up, got through the first few gears and it still seemed like the throttle was sticking open, between shifts I noticed it wasn't coming down to idle fast enough..

from there out it wouldn't ever idle down below like 1800-2200- rpms, it had me a bit worried..

I managed to get it back to the house like that just fine, it was tough shifting not knowing the tranny well (first drive) and that high idle..

then I noticed it didn't run as good down low, it would stumble a bit until it cought up between shifts, almost like it needed the turbo spooled to run ok..

my TB is closing all the way, its good, and in an effort to curb the high idle I turned the idle adjustment all the way in, slowed it down a touch but not much, didn't really help..

I think that there may be something wrong with the AAV or throttle bypass valve.. sticking open and causing it to idle high or something...

there is very likely a vaccume leak between the turbo and the dizzy, I need to check that again now that's its all shook up good, but I don't really see that causing a high idle..

and while idleing high while I was trying to figure it out I could ever so slightly push down on the air metering plate making it too rich to slow the idle down to tolerable levels so I could inspect under the hood while it was running.. that high idle made me a bit nervous..

it was also quite hot, I had to idle it for a while to feel safe to shut it off, manifold/turbine housing had a touch of red...

idk.. just something else for me to chase down..

ive probably fixed over 100 things on this car already, one more cant hurt I suppose..

idk ill go digging this sight and see what I can find I suppose
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80 Turbo - Slightly Modified

[Paul]

All efforts are wasted until the system is air tight.
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[Fasteddie313]

[Rasta Monsta]

BROKEN RECORD TIME:

There is no way to reliably check a 931 for air leaks without a smoke machine.

A mechanic should do this for you for less than one hour's shop time.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[sciroccosteve]

[Fasteddie313]

thought about that smoke machine...

im kinda in a rural area, I don't think its realistic to try to get some mechanic and a machine to my car, unless I trailer it to a shop...

all new hoses would be cheaper, ive already replaces a few 90's and inspected everything I could find...

the car runs extremely well as far as drivability but I still cnat get the idle to stay down below 1500-1800 or so even with the air screw all the way in..

I am now almost 100% positive that its the decel valve..

sometimes when I start it up it will give me a super low idle (always starts with no throttle), and then if I can make it to the TB from the gas pedal to keep it running I can get a great idle with the TB air screw and dizzy mix screw... for a minute..

and then it seems if I blip the throttle by hand a couple times it will never settle back down to that nice idle, back up to 1500-1800 it stays until I start it over from scratch again.. pretty much in line with if the blow off valve pops off then the 1800 idle is there to stay for then.. im thinking decel valve.. I think it operates on the same vaccume principal that a bov does.. and its sticking open a bit...

between gears im getting an very slow rev down from 3500 down to 1800 or so..

and/or im not getting anything from the passengers side rad fan.. im not sure what the cause is but it may be a bad temp sensor witch I think I read could also fail to a cold read making you AAV open like its trying to idle a cold engine..

I don't think its the dizzy or wur because it just runs too well the way it is beside the high idle..

it is getting air into the manifold after the TB somehow whilst it shouldn't be..
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80 Turbo - Slightly Modified

[SlayerSST]

Don't expect to ever finish this car.


These cars are never-ending projects.

+ on that decel valve and replacing all the hoses with silicone ones.

[Fasteddie313]

I am suspicious of 2 3 and 7..

suspicious of the AAV or aux air regulator as it says here and the decal valve..

the only thing is I couldn't figure out witch of 3 and 7 the decel valve was.. now I know its 3..

what exactly does that purge valve do btw if you don't mind me asking?

and what is that arrow going into it supposed to represent?
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80 Turbo - Slightly Modified

[SlayerSST]

I think its like a small filter but I'm not sure.

The arrow is for the charcoal canister hose. Charcoal canister is bolted onto the side of the car, hidden by the driver side fender.

[Rasta Monsta]

Purge valve vents the fuel tank fumes into intake in high vacuum situations.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Paul]

Throttle position switch working?
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[Fasteddie313]

[Fasteddie313]

but the mission of the day today was to drive the car from my one location to the other now that all the big stuff is done..

today I started it cold with no throttle, started right up great and idled super low, after 20 seconds or so it idled up to 800 ish and stayed there for a good 10 minutes and through a couple light throttle blips...

drove the car and once we got about 3 miles that high idle reared its ugly head, back to 1800 again.. and didn't get much of anything on my temp gague, like it barely moved through a 10-15 min idle warm up and a 5-6 mile drive..

I am suspecting a temp sensor now, what I believe to be a temp sensor, at the top right inside of the radiator from the front of the car, I found unplugged and plugged it back in, maybe there was a reason it was unplugged..

and the drivers rad fan runs after shutdown on a lowish speed..

but I don't think ive ever got the pasengers rad fan on nor the drivers in high speed.. I believe the same sensor could be the reason im not getting fans, bad temp gague, and the AAV not closing when the engine gets up to temp,

thank got for good old physical thermostats...

I believe there are 2 temp sensors, one for regular and one for that after shutdown low speed rad fan with a resistor in the circuit, I believe I have the resistor one working correctly..

where is the other temp sensor located? I haven't found it yet, and also hane not tested the passengers fan at all yet manually...

off to search for the location of that temp sensor and troubleshoot it as best I can..

I have a multimeter at my disposal, I hope I can find the resistance specs or whatever for the sensor, I hope its just unplugged or something..


I did just last night find a wire, black as far as I can tell so far, that looks like it comes from the drivers side firewall area, runs forward on the drivers front wheel well where there is a inline plug, them more wire wrapped around an ac hose right there under the drivers headlight area on the wheel well side...

and it goes to nothing, and I haven't the slightest idea what it is for but I just found it going to nothing...

ill try to get a pic of it up if I cant figure out what it is on my own...

thanks guys btw.. I would never ever have been able to get this far without this forum, I owe it all to you..
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80 Turbo - Slightly Modified

[Fasteddie313]

im not finding anything good on what the temp sensors do other than that one on the radiator...

saw something about a hard pipe with 3 more of them on it...

and lets say that the aav isn't closing because of the temp sensor or some other reason, it seems if I unplug the aav I get no change in idle charactoristics what so ever..

idle very low when cold, idle very high when warm or its driven, no rad fans other than the drivers on low....

I don't know but god does she run good, but im not going to run it hard at all until I get the ARF set well and I cant do that until I get the idle set well, or even adjustable..

nose back under the hood I go..
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80 Turbo - Slightly Modified

[Carrera RSR]