Hard acceleration.
09-11-2017, 02:47 AM
#1
Hard acceleration.
Good evening to all, went out today in my 85 s3 5spd, and while driving when the car was cold, I'm assuming the temp outside was around 95_100, anyway, I get on the gas and the car takes off then all of a sudden it falls flat around 3k,rpm as if the car has died back out of throttle just a hair and she takes off, this continues until the car is warm then no issues at all, have done intake refresh, new wires plugs, maf , I have not done the tps or the ISV, any direction would be greatly appreciated thanks in advance.
09-11-2017, 07:13 AM
#3
Rennlist Member
No idea what your car tells you but mine tells me she does not want to rev until she is warm. No idea why this is but once she is up to temperature then and only then do I let the motor rev high. I put this down to tight build clearances.
As the motor warms up the enrichment mapping is variable with temperature and this is the case until the motor hits about 80C and once it reaches that point transient warm up enrichment is more or less over. What you are feeling is likely connected to this process and if the temperature sender is a bit out of calibration I dare say it might cause a flat spot and thus no issue when the motor is fully warmed.
As the motor warms up the enrichment mapping is variable with temperature and this is the case until the motor hits about 80C and once it reaches that point transient warm up enrichment is more or less over. What you are feeling is likely connected to this process and if the temperature sender is a bit out of calibration I dare say it might cause a flat spot and thus no issue when the motor is fully warmed.
09-11-2017, 11:15 PM
#4
update so this morning replaced the fuel filter, didn't know the last time it was done a way the problem still exists, will replace my tps since I have one new will post my results .thanks for your time and advice.
09-11-2017, 11:25 PM
#5
Rennlist Member
Check your fuel pressure. I have the same symptoms and I am thinking that my fuel pump is failing and consequently my fuel pressure is dropping off.
I am changing fuel pumps and I will let you know the outcome.
I am changing fuel pumps and I will let you know the outcome.
09-12-2017, 11:22 AM
#6
Rennlist Member
I believe the TEmp II is related to FredR's comments; search here for checking the voltages on that.
also wires, including coil wires??
Once in an '85, at speed warm engine, I could not accel in 5th past 60 to 65 mph, like a governor was holding it. Turned out to be corrosion on a coil wire. Easy fix that time.
also wires, including coil wires??
Once in an '85, at speed warm engine, I could not accel in 5th past 60 to 65 mph, like a governor was holding it. Turned out to be corrosion on a coil wire. Easy fix that time.
09-16-2017, 01:30 AM
#7
No idea what your car tells you but mine tells me she does not want to rev until she is warm. No idea why this is but once she is up to temperature then and only then do I let the motor rev high. I put this down to tight build clearances.
As the motor warms up the enrichment mapping is variable with temperature and this is the case until the motor hits about 80C and once it reaches that point transient warm up enrichment is more or less over. What you are feeling is likely connected to this process and if the temperature sender is a bit out of calibration I dare say it might cause a flat spot and thus no issue when the motor is fully warmed.
As the motor warms up the enrichment mapping is variable with temperature and this is the case until the motor hits about 80C and once it reaches that point transient warm up enrichment is more or less over. What you are feeling is likely connected to this process and if the temperature sender is a bit out of calibration I dare say it might cause a flat spot and thus no issue when the motor is fully warmed.
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09-16-2017, 01:41 AM
#8
I believe the TEmp II is related to FredR's comments; search here for checking the voltages on that.
also wires, including coil wires??
Once in an '85, at speed warm engine, I could not accel in 5th past 60 to 65 mph, like a governor was holding it. Turned out to be corrosion on a coil wire. Easy fix that time.
also wires, including coil wires??
Once in an '85, at speed warm engine, I could not accel in 5th past 60 to 65 mph, like a governor was holding it. Turned out to be corrosion on a coil wire. Easy fix that time.
09-21-2017, 01:36 AM
#11
update, so I have yet to replace anything, but I have noticed that if I allow the car to warm up, then drive not one issue, the car is super responsive, all is fine just start up and drive then there is a flat spot until warm, so no real fix just added a little patience before the drive.cheers to all.
09-21-2017, 10:49 AM
#12
Rennlist Member
What is the configuration of your cold air intake? The factory intake is a cold air intake, so assuming you just prettied it up it should have little to no affect. haw far of a departure is yours? Pics may help.
09-21-2017, 11:24 AM
#13
sorry for no pics, but the air box both inside and out have been wrapped in gold laminate heat shielding cloth like tape, outer is wrapped in same material except it's silver, have also replaced the airtubeairtubes.will take pics when I get a chance.
