Car starts up, but needs to rev up to stay on
12-24-09, 10:47 PM
#1
Car starts up, but needs to rev up to stay on
Hey guys,
I've come across a pretty annoying problem. I have an S5 T2. The car is completely stock. NOTHING has been done to it other than a rebuild. It has however, been sitting for 3 years in my friend's garage. Then i bought it and that was probably the first time it's been driven in a while.
So here's the thing, everytime I go to start up the car it would start, but if I didn't add any throttle to it, it would die. I would have to let it warm it before it would idle. Another thing I've noticed is that when I hold the throttle, I can see the Tach needle move up and down slightly.
I went out today and took off the BAC and tried to see if it was dirty or anything, but I didn't see anything. I'm pretty sure it's not a vacuum leak otherwise it would have a really bad idle and would drive like crap right?
I've searched a few times but I don't understand what people mean when they say closed loop or something. And do I check the TPS sensor from the where where it goes into the plug? or at the points inside the plug?
Would low compression also cause it to do something like this as well? In otherwords die when I try to start it up? It does have to crank over for like 3-5secs before it will start up. Maybe the plugs are kinda bad?
Any help is appreciated!
I've come across a pretty annoying problem. I have an S5 T2. The car is completely stock. NOTHING has been done to it other than a rebuild. It has however, been sitting for 3 years in my friend's garage. Then i bought it and that was probably the first time it's been driven in a while.
So here's the thing, everytime I go to start up the car it would start, but if I didn't add any throttle to it, it would die. I would have to let it warm it before it would idle. Another thing I've noticed is that when I hold the throttle, I can see the Tach needle move up and down slightly.
I went out today and took off the BAC and tried to see if it was dirty or anything, but I didn't see anything. I'm pretty sure it's not a vacuum leak otherwise it would have a really bad idle and would drive like crap right?
I've searched a few times but I don't understand what people mean when they say closed loop or something. And do I check the TPS sensor from the where where it goes into the plug? or at the points inside the plug?
Would low compression also cause it to do something like this as well? In otherwords die when I try to start it up? It does have to crank over for like 3-5secs before it will start up. Maybe the plugs are kinda bad?
Any help is appreciated!
12-24-09, 10:54 PM
#2
EDITED WITH TPS ADJUSTMENT INFO:
Closed loop has nothing to do with idle.
You check the TPS at the harness going into the TPS by backprobing the green/red wire with a paper clip and use a multimerter to get the voltage with the car running and adjust the screw until you get the appropriate voltage. You are basically touching the red meter lead with the paper clip, and using the black lead on a ground, battery works fine. Adjust until you get 1V. Make sure your car is fully warmed up.
I think on the T2 the BAC has an an adjustment screw for the idle, also get the FSM and test out the BAC properly and make sure it's not dead. There is also a thermal pellet on the throttle body that may not be doing it's job. The FSM covers all this.
Closed loop has nothing to do with idle.
You check the TPS at the harness going into the TPS by backprobing the green/red wire with a paper clip and use a multimerter to get the voltage with the car running and adjust the screw until you get the appropriate voltage. You are basically touching the red meter lead with the paper clip, and using the black lead on a ground, battery works fine. Adjust until you get 1V. Make sure your car is fully warmed up.
I think on the T2 the BAC has an an adjustment screw for the idle, also get the FSM and test out the BAC properly and make sure it's not dead. There is also a thermal pellet on the throttle body that may not be doing it's job. The FSM covers all this.
12-24-09, 11:53 PM
#4
I mean, the car starts up perfectly fine, but it just won't stay on until it warms up. I've only driven it once. I'm hoping after I do a tuneup on it, the hard start will go away.
I appreciate the help guys, I will check the BAC and TPS tomorrow, and if possible I'll get a compression test sometime next week. Hopefully it won't need a rebuild for a year =P
I appreciate the help guys, I will check the BAC and TPS tomorrow, and if possible I'll get a compression test sometime next week. Hopefully it won't need a rebuild for a year =P
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