Ben W
Probationary Member
- 25
- 2
- Mar 7, 2017
-
Camp Lejeune,
North Carolina
Forgive the oncoming wall of text- im trying to provide all the details of the quirks surrounding this behaviour
So ive had the car for over 6 years, and to my memory this surge behaviour has always been there, BUT, since up until recently I never worked a "traditional" job (was Military, followed by student) i never really got caught in traffic consistently, so this was a fairly rare nuisance.
Since getting a "traditional" job, ive unfortunately started encountering traffic on my daily commute, which makes this surging appear almost every day
Behavior:
Idle surges from 1000rpm (which is slightly above normal idle) up to anywhere from 1200-1800 rpm, and then drops back down
(As if someone was lightly blipping the accelerator)
Trigger:
The engine must be FULLY hot, and then you simply get into stop and go traffic; going in and out of idle repeatedly in this hot-engine state is what seems to trigger it
Additional Quirks:
The above mentioned surging is the PRIMARY behaviour, but there is some variation, from how fast it surges up and down, to sometimes the idle simply SITS high (Ive noticed a difference in behaviour between rolling idle and sitting idle)
Additionally, ive noticed that if i get out during the surging behavior, go under the hood, and physically push the throttle return spring mechanism closed, the idle drops back down to normal
However, getting back into the car and doing anything triggers the surging again
AFR's read "normal" for someone slightly blipping the accelerator
As it climbs up, its 14.7
And then cuts as the idle drops back down from the surge
Actual driveability is totally unaffected as far as I can tell
Cruises nicely at 14.7, no strange behaviour
With enough time NOT in traffic, i can once again go into idle, and the idle is normal
The Car
Is NOT stock, at all
Its been awhile, so I cant remember everything in it
But I can tell you any major installs that are involved
Front Mount Intercooler
500cc Deatschwerks injectors
etc
It was tuned about 6 years ago, at sea level
I know live in Denver so im gonna get it retuned once I replace my Turbo this summer
But like I said, even when I was living sea level, i remember this surging occurring from time to time
Any idea what the cause may be?
I recently replaced the Throttle Position sensor, but that didnt fix it
So ive had the car for over 6 years, and to my memory this surge behaviour has always been there, BUT, since up until recently I never worked a "traditional" job (was Military, followed by student) i never really got caught in traffic consistently, so this was a fairly rare nuisance.
Since getting a "traditional" job, ive unfortunately started encountering traffic on my daily commute, which makes this surging appear almost every day
Behavior:
Idle surges from 1000rpm (which is slightly above normal idle) up to anywhere from 1200-1800 rpm, and then drops back down
(As if someone was lightly blipping the accelerator)
Trigger:
The engine must be FULLY hot, and then you simply get into stop and go traffic; going in and out of idle repeatedly in this hot-engine state is what seems to trigger it
Additional Quirks:
The above mentioned surging is the PRIMARY behaviour, but there is some variation, from how fast it surges up and down, to sometimes the idle simply SITS high (Ive noticed a difference in behaviour between rolling idle and sitting idle)
Additionally, ive noticed that if i get out during the surging behavior, go under the hood, and physically push the throttle return spring mechanism closed, the idle drops back down to normal
However, getting back into the car and doing anything triggers the surging again
AFR's read "normal" for someone slightly blipping the accelerator
As it climbs up, its 14.7
And then cuts as the idle drops back down from the surge
Actual driveability is totally unaffected as far as I can tell
Cruises nicely at 14.7, no strange behaviour
With enough time NOT in traffic, i can once again go into idle, and the idle is normal
The Car
Is NOT stock, at all
Its been awhile, so I cant remember everything in it
But I can tell you any major installs that are involved
Front Mount Intercooler
500cc Deatschwerks injectors
etc
It was tuned about 6 years ago, at sea level
I know live in Denver so im gonna get it retuned once I replace my Turbo this summer
But like I said, even when I was living sea level, i remember this surging occurring from time to time
Any idea what the cause may be?
I recently replaced the Throttle Position sensor, but that didnt fix it
