S4 T2 Can't Hold Idle
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S4 T2 Can't Hold Idle
Hello Everyone,
Today on my way to do some christmas shopping, on a wet rainy day, i jumped on the freeway and drove about for 4 miles and exit off, and when i was coming to a stop, the car's idle just jumpped to 4ooo rpm. I quickly pulled into a gas station and popped the hood. First, i notice the afm sealant has partially came off. You know, the sealant on top of the AFM, and it black. So I went to Kragen and got me some sealant and sealed it. Now the car is fluctuaing at idle bewteen 1300 and 1800 rpm very quickly. I check the TPS and noticed when i pushed in the TPS, the car's idle jumped even higher, like to 3000 rpm,when it was suppose to stumble.
I wonder if you can help me out.
Why is my idle, all in sudden, is fluctuating? Please help out.
Thanks everyone.
Today on my way to do some christmas shopping, on a wet rainy day, i jumped on the freeway and drove about for 4 miles and exit off, and when i was coming to a stop, the car's idle just jumpped to 4ooo rpm. I quickly pulled into a gas station and popped the hood. First, i notice the afm sealant has partially came off. You know, the sealant on top of the AFM, and it black. So I went to Kragen and got me some sealant and sealed it. Now the car is fluctuaing at idle bewteen 1300 and 1800 rpm very quickly. I check the TPS and noticed when i pushed in the TPS, the car's idle jumped even higher, like to 3000 rpm,when it was suppose to stumble.
I wonder if you can help me out.
Why is my idle, all in sudden, is fluctuating? Please help out.
Thanks everyone.
#3
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I don't have a TID. I moved it to the cold side of the intercooler.
I ohms test on the TPS and AFM and everything is specifications!!!!!!!!!!
AHHHHHHHH!
Anymore ideas.
I will check the pressure sensor tomorrow. i want to check the fuel pressure regulator, but how do you do it without a vacuum pump?
I ohms test on the TPS and AFM and everything is specifications!!!!!!!!!!
AHHHHHHHH!
Anymore ideas.
I will check the pressure sensor tomorrow. i want to check the fuel pressure regulator, but how do you do it without a vacuum pump?
#6
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I will recheck the clamps, from TURBO to the TB.
I would think i would have an air leak after the TB, correct me if im wrong, because if it's after the AFM and before the TB, it would cause a misfire(air leak) and the car would want to die. And if it after the TB and AFM, then it's a vacuum leak which cause the car to over rev or idle high.
No matter what, Karach, your right. It has to be a air/vacuum leak. But would any sensors, like the pressure sensor, or the FPR would have an effect on it?
I would think i would have an air leak after the TB, correct me if im wrong, because if it's after the AFM and before the TB, it would cause a misfire(air leak) and the car would want to die. And if it after the TB and AFM, then it's a vacuum leak which cause the car to over rev or idle high.
No matter what, Karach, your right. It has to be a air/vacuum leak. But would any sensors, like the pressure sensor, or the FPR would have an effect on it?
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#9
soooo you blew off the black plastic cap ... with boost ... assuming all your piping from afm to tb is good ... did you check the electrical inside the cap b4 u sealed it back up?
#11
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Hrm I had a simliar problem. I tightend my throttle cable too much.
With the tps it would be a lot easier to see with an safc.
Though from the looks of it, it seems your car is idling high somehow and you have a vac leak so of course the car is hesitating to want to die, but since your idling so high it cant.
Check TPS screw, throttle cable make sure it isnt too tight, loosen if you have to.
For the vac leak, buy some brake cleaner and spray all around. Watch for hissing noises. Put your finger around the problem area(s) if there is a vac leak youll hear it.
I know it seems like i'm just throwing out random things to check, but like i said I've had similar problems.
With the tps it would be a lot easier to see with an safc.
Though from the looks of it, it seems your car is idling high somehow and you have a vac leak so of course the car is hesitating to want to die, but since your idling so high it cant.
Check TPS screw, throttle cable make sure it isnt too tight, loosen if you have to.
For the vac leak, buy some brake cleaner and spray all around. Watch for hissing noises. Put your finger around the problem area(s) if there is a vac leak youll hear it.
I know it seems like i'm just throwing out random things to check, but like i said I've had similar problems.
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I did blow off the black plastic cap off the afm. One corner came off and i sealed it back up without checking the electrical. But i did the resistance test on it and everything is in specifications for the AFM. I wil recheck it though, because i do feel it is electrical.
As for vacuum leaks, i don't have any emissions, and everthing capped off. I have an S5 T2 manifold with all the block off plates including the BAC being blocked off. But i will recheck them.
I will take all suggestions into consideration and will recheck everthing. Thanks guys, keep them coming.
As for vacuum leaks, i don't have any emissions, and everthing capped off. I have an S5 T2 manifold with all the block off plates including the BAC being blocked off. But i will recheck them.
I will take all suggestions into consideration and will recheck everthing. Thanks guys, keep them coming.
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I retighten every clamp, resealed every gasket, and no difference. But there was something went wrong. One of my secondary injector ohm resistor blew up and caused a small fire ball. I rechecked the surroundings and wires and everything is fine.
If one a fuel injector, like the secondaries, would it cause high idle and unstable idle?
I popped off the afm's black cap and rechecked the wires, and no connection or circuit show any sign of wear of burns. So i resealed it and put it back.
I think this is a sign for me to get my EMS ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If one a fuel injector, like the secondaries, would it cause high idle and unstable idle?
I popped off the afm's black cap and rechecked the wires, and no connection or circuit show any sign of wear of burns. So i resealed it and put it back.
I think this is a sign for me to get my EMS ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#15
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ok...the tPS was out of whack because somehow...the green wire was severed...the black was gettin there and the brown reference wire was ok. we happened to find an uncapped vaccum line between the primary injectors. AFAIK, sao1 plugged it up, but it didn't change his problem...
Also, his manifold starts glowing red-orange after about a minute of the car running. I'm thinking that maybe one of his primary injectors is stuck open...
So far, we've checked any vaccum lines left on is engine, loosened the idle stop screw, screwed with the TPS, checked for piping leaks, and messed with the variable resistor thinking that maybe it would do something....obviously, at 3k rpms, the VR didn't do ****...
So...after running through all of those things in search of the cause of his problem, the idle still jumps to 3k and holds there....
anything we may be overlooking??
Also, his manifold starts glowing red-orange after about a minute of the car running. I'm thinking that maybe one of his primary injectors is stuck open...
So far, we've checked any vaccum lines left on is engine, loosened the idle stop screw, screwed with the TPS, checked for piping leaks, and messed with the variable resistor thinking that maybe it would do something....obviously, at 3k rpms, the VR didn't do ****...
So...after running through all of those things in search of the cause of his problem, the idle still jumps to 3k and holds there....
anything we may be overlooking??
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Alright... new updates. Still running at a constant 3k rpm and the turbo manifold is glowing red in about 5 minutes from start up.
Changed the fuel filter and it drop the idle to 2500rpm and then slowly goes to 3000rpm.
What else can i check or test?
Thanks!
Changed the fuel filter and it drop the idle to 2500rpm and then slowly goes to 3000rpm.
What else can i check or test?
Thanks!
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i still think the car is insuffient fuel or the fuel is combusting in the manifold according to some articles i found in SEARCH. But that doesn't explain the 3k rpm idle!
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