Weird hesitation
04-13-10, 12:05 PM
#1
Weird hesitation
This started last week and its driving me crazy.
Its just a weird type of hesitation. I have no idea where it came from or what happened. It seems to happen in any gear. I thought it might be clutch slipping but its a fairly new oem clutch with roughly 13-15k miles on it. It's kind of hard to describe, but it feels like when the throttle is lightly being pressed the car hesitates and does this weird thing like I'm pushing the throttle down and letting off of it really fast but my foot is completely still at the same position.
I usually have to press more to make it stop or go away for a few seconds. I thought it was a vacuum leak, but the only leak i found was that the hose for the cruise control had cracked at the end. I already replaced it but it didn't help at all. I've tried to adjust the tps and see if that made a difference. It didn't.
The car is a stock s4 vert. I recently did an engine swap with a rebuilt engine with 10k. It felt fine up until last week. There is no loss of power from the actual engine but it feels like something else is causing this to happen. I thought it might be the transmission, but I don't know. I thought it was clutch slip but I don't think thats the case here, but I could be wrong.
I'd really like to have an idea of what I should check because I have no idea what to check right now. Everything in the engine bay looks fine. I've checked the computer for codes. No leaks anywhere.
I don't know if it makes a difference, but I've been using difference shifters, one fb shifter and two fc shifters to see what i liked better. I'm using the fc shifter. But that wouldn't cause the problem...would it?
Its just a weird type of hesitation. I have no idea where it came from or what happened. It seems to happen in any gear. I thought it might be clutch slipping but its a fairly new oem clutch with roughly 13-15k miles on it. It's kind of hard to describe, but it feels like when the throttle is lightly being pressed the car hesitates and does this weird thing like I'm pushing the throttle down and letting off of it really fast but my foot is completely still at the same position.
I usually have to press more to make it stop or go away for a few seconds. I thought it was a vacuum leak, but the only leak i found was that the hose for the cruise control had cracked at the end. I already replaced it but it didn't help at all. I've tried to adjust the tps and see if that made a difference. It didn't.
The car is a stock s4 vert. I recently did an engine swap with a rebuilt engine with 10k. It felt fine up until last week. There is no loss of power from the actual engine but it feels like something else is causing this to happen. I thought it might be the transmission, but I don't know. I thought it was clutch slip but I don't think thats the case here, but I could be wrong.
I'd really like to have an idea of what I should check because I have no idea what to check right now. Everything in the engine bay looks fine. I've checked the computer for codes. No leaks anywhere.
I don't know if it makes a difference, but I've been using difference shifters, one fb shifter and two fc shifters to see what i liked better. I'm using the fc shifter. But that wouldn't cause the problem...would it?
04-13-10, 04:59 PM
#5
i think i fixed it. i got home and followed some instructions i found of how to adjust the tps. i got +/- 1 ohm within 1k and i drove the car around the block and seems to not hesitate during acceleration anymore.
i followed these instructions from Aaron Cake
i followed these instructions from Aaron Cake
Adjusting the TPS is a simple maintenance item that should be
preformed at any oil change. The benefits include better gas mileage,
better performance and a smoother idle. Adjustment only takes a few
minutes if you follow the directions below.
What You Need
· Ohmmeter
· Flathead Screwdriver
· Half an hour
How To Adjust
· Warm the car completely by driving for 20 minutes
· If your car is a turbo, remove the intercooler. Loosen the hose
clamps on the inlet and outlet, remove the vacuum line, and then
remove the four bolts (I believe 11 or 12MM). Lift off the cooler. Do
this quickly so the car does not cool.
· Unplug the TPS. On 89+ cars, you want to unplug the connector
leading from the lower TPS.
· Hold the TPS connector so the hump points up. Connect your meter
between top connection and rightmost connection.
· Adjust the stop screw until the meter reads 1K (1000 Ohms)
· Plug the TPS back in
· If necessary, reinstall the intercooler. Don’t overtighten the hose clamps
· Drive the car for a few minutes, then repeat the procedure
preformed at any oil change. The benefits include better gas mileage,
better performance and a smoother idle. Adjustment only takes a few
minutes if you follow the directions below.
What You Need
· Ohmmeter
· Flathead Screwdriver
· Half an hour
How To Adjust
· Warm the car completely by driving for 20 minutes
· If your car is a turbo, remove the intercooler. Loosen the hose
clamps on the inlet and outlet, remove the vacuum line, and then
remove the four bolts (I believe 11 or 12MM). Lift off the cooler. Do
this quickly so the car does not cool.
· Unplug the TPS. On 89+ cars, you want to unplug the connector
leading from the lower TPS.
· Hold the TPS connector so the hump points up. Connect your meter
between top connection and rightmost connection.
· Adjust the stop screw until the meter reads 1K (1000 Ohms)
· Plug the TPS back in
· If necessary, reinstall the intercooler. Don’t overtighten the hose clamps
· Drive the car for a few minutes, then repeat the procedure
04-15-10, 04:31 PM
#6
ok so the hesitation came back. i don't think its coming from the engine.
transmission? differential?
i've been meaning to change the oil in the transmission with some 75w-90 royal purple gear oil, but its raining and i cant do that yet. could this have any affect on this stupid hesitation? or would i just have to try and see?
i can rev the engine freely and there is no hesitation at all. goes all the way to 7k and back to idle just fine.
any ideas of what else i should check?
transmission? differential?
i've been meaning to change the oil in the transmission with some 75w-90 royal purple gear oil, but its raining and i cant do that yet. could this have any affect on this stupid hesitation? or would i just have to try and see?
i can rev the engine freely and there is no hesitation at all. goes all the way to 7k and back to idle just fine.
any ideas of what else i should check?
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