Maddening idle issue
01-17-2002, 01:09 PM
#1
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Maddening idle issue
Ok, I have this idle issue that's been driving me bonkers since Day One.
I get in the car, start it up. It runs like a champ, all is well. I'm truckin' around like nobody's business.
Until I stop.
If I stall it (which I still do occasionally! :rolleyes
or shut it off briefly and then re-start, it won't idle! The second I let my foot off the gas it just dies, and if it doesn't die immediately, it will oscillate a few times, the perigee of the swing getting lower and lower until it croaks, like how they'd milk a death scenes in those old spaghetti westerns.
Reference points: 1990 3.6L in a '77 911 with Patrick Motorsports lightended flywheel and crank pulley. Cyntex chip with (supposedly) special code to deal with the lighter flywheel.
It's fine if I don't shut it off or stall it, but once I do, I have a heck of a time getting it to idle again!
Thanks!
I get in the car, start it up. It runs like a champ, all is well. I'm truckin' around like nobody's business.
Until I stop.
If I stall it (which I still do occasionally! :rolleyes
or shut it off briefly and then re-start, it won't idle! The second I let my foot off the gas it just dies, and if it doesn't die immediately, it will oscillate a few times, the perigee of the swing getting lower and lower until it croaks, like how they'd milk a death scenes in those old spaghetti westerns.Reference points: 1990 3.6L in a '77 911 with Patrick Motorsports lightended flywheel and crank pulley. Cyntex chip with (supposedly) special code to deal with the lighter flywheel.
It's fine if I don't shut it off or stall it, but once I do, I have a heck of a time getting it to idle again!
Thanks!
01-17-2002, 05:09 PM
#2
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Dear Thom,
When they wired in your harness make sure they hot wired the DME to the battery. It almost sounds like the DME is being reset everytime.
Unfortunately the most common causes of this problem are the LWF and these aftermarket chips (despite what they say). Being a transplanted 3.6 it is tough to help much further. The fact that it runs like a champ until you stop or stall suggests to me a DME related problem,
Ciao,
Adrian
911C4
When they wired in your harness make sure they hot wired the DME to the battery. It almost sounds like the DME is being reset everytime.
Unfortunately the most common causes of this problem are the LWF and these aftermarket chips (despite what they say). Being a transplanted 3.6 it is tough to help much further. The fact that it runs like a champ until you stop or stall suggests to me a DME related problem,
Ciao,
Adrian
911C4
01-17-2002, 06:26 PM
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Is there any way to tell for certain a) if the unit is/is not hot wired to the battery; b) if it's truly being reset each time.
What wire goes to the battery?
What wire goes to the battery?
Originally posted by Adrian:
<STRONG>Dear Thom,
When they wired in your harness make sure they hot wired the DME to the battery. It almost sounds like the DME is being reset everytime.
Unfortunately the most common causes of this problem are the LWF and these aftermarket chips (despite what they say). Being a transplanted 3.6 it is tough to help much further. The fact that it runs like a champ until you stop or stall suggests to me a DME related problem,
Ciao,
Adrian
911C4</STRONG>
<STRONG>Dear Thom,
When they wired in your harness make sure they hot wired the DME to the battery. It almost sounds like the DME is being reset everytime.
Unfortunately the most common causes of this problem are the LWF and these aftermarket chips (despite what they say). Being a transplanted 3.6 it is tough to help much further. The fact that it runs like a champ until you stop or stall suggests to me a DME related problem,
Ciao,
Adrian
911C4</STRONG>
01-17-2002, 07:31 PM
#4
Burning Brakes
I think what Adrian is saying is to check that you have constant voltage to the DME. Can't remember what pins to check for that, but, there is a set of pins that should have 12V all the time.
01-18-2002, 04:14 AM
#5
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Dear Thom,
One way to check this is to do the following.
Go for a drive. 10 minutes say. Get everything warmed up. Stop and turn the engine OFF but DO NOT TURN THE IGNITION SWITCH TO OFF, just turn the engine off but keep the 911 powered. Then start again. See what happens. If the idle is steady etc and you can drive off without further problems, stop again and this time turn the engine and ignition completely off and try again. If the thing plays up it means the DME is not getting power and its adaptive memory has been erased.
Worth a try. To physically check the thing is powered you will need to access the plug and check for 12 volts when the ignition is off. I will not tell you the connector number. I would like you to check every pin and tell me which pin numbers have 12VDC on them. There is a reason for this.
Ciao,
Adrian
911C4
One way to check this is to do the following.
Go for a drive. 10 minutes say. Get everything warmed up. Stop and turn the engine OFF but DO NOT TURN THE IGNITION SWITCH TO OFF, just turn the engine off but keep the 911 powered. Then start again. See what happens. If the idle is steady etc and you can drive off without further problems, stop again and this time turn the engine and ignition completely off and try again. If the thing plays up it means the DME is not getting power and its adaptive memory has been erased.
Worth a try. To physically check the thing is powered you will need to access the plug and check for 12 volts when the ignition is off. I will not tell you the connector number. I would like you to check every pin and tell me which pin numbers have 12VDC on them. There is a reason for this.
Ciao,
Adrian
911C4
01-18-2002, 02:07 PM
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Thanks Adrian - I'll try and do this this weekend and report back!
Originally posted by Adrian:
<STRONG>Dear Thom,
One way to check this is to do the following.
Go for a drive. 10 minutes say. Get everything warmed up. Stop and turn the engine OFF but DO NOT TURN THE IGNITION SWITCH TO OFF, just turn the engine off but keep the 911 powered. Then start again. See what happens. If the idle is steady etc and you can drive off without further problems, stop again and this time turn the engine and ignition completely off and try again. If the thing plays up it means the DME is not getting power and its adaptive memory has been erased.
Worth a try. To physically check the thing is powered you will need to access the plug and check for 12 volts when the ignition is off. I will not tell you the connector number. I would like you to check every pin and tell me which pin numbers have 12VDC on them. There is a reason for this.
Ciao,
Adrian
911C4</STRONG>
<STRONG>Dear Thom,
One way to check this is to do the following.
Go for a drive. 10 minutes say. Get everything warmed up. Stop and turn the engine OFF but DO NOT TURN THE IGNITION SWITCH TO OFF, just turn the engine off but keep the 911 powered. Then start again. See what happens. If the idle is steady etc and you can drive off without further problems, stop again and this time turn the engine and ignition completely off and try again. If the thing plays up it means the DME is not getting power and its adaptive memory has been erased.
Worth a try. To physically check the thing is powered you will need to access the plug and check for 12 volts when the ignition is off. I will not tell you the connector number. I would like you to check every pin and tell me which pin numbers have 12VDC on them. There is a reason for this.
Ciao,
Adrian
911C4</STRONG>