Trailing Throttle Hesitation
05-06-2011, 12:11 PM
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Trailing Throttle Hesitation
My AP-1 has a very slight intermittent hesitation when I step lightly on the gas. It seems to be worst coming off trailing throttle, especially after a downhill stretch using engine braking. It's more annoying than anything, but the car runs great otherwise. Turning the ignition off and on to reset the computer doesn't clear it. No CEL and no codes. Before I throw in a MAP sensor, what are your suggestions? (Mileage is 125K.)
05-06-2011, 12:16 PM
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What's the mainenance history?
Plugs, air filter?
Any blue smoke out the exhaust when you get on the throttle after engine braking?
Is the throttle body clean?
Is the hesitation in the throttle cable or the engine picking up?
How much slack in the throttle cable?
(^) check this first!
Plugs, air filter?
Any blue smoke out the exhaust when you get on the throttle after engine braking?
Is the throttle body clean?
Is the hesitation in the throttle cable or the engine picking up?
How much slack in the throttle cable?
(^) check this first!
05-07-2011, 04:30 PM
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I picked up the car a little over a month ago, so don't know the history. It has good maintenance records and under the hood has been regularly cleaned. The PO definitely took care of the car.
Plugs, air filter? Not sure on the plugs. I'll put those on the fix list, right after the cam chain tensioner (which is scheduled for tomorrow). AF is almost new.
Any blue smoke out the exhaust when you get on the throttle after engine braking? No blue smoke and oil consumption is reasonable.
Is the throttle body clean? Not sure, will check this.
Is the hesitation in the throttle cable or the engine picking up? It's in engine pickup. It's nothing....nothing....oops, time to wake up!
How much slack in the throttle cable? Throttle cable was extremely loose when I picked up the car. I stopped and tightened it up even before I got home, very annoying!
I like your Spit! That's on my punch list. Nearest I've come is a T-34.
Plugs, air filter? Not sure on the plugs. I'll put those on the fix list, right after the cam chain tensioner (which is scheduled for tomorrow). AF is almost new.
Any blue smoke out the exhaust when you get on the throttle after engine braking? No blue smoke and oil consumption is reasonable.
Is the throttle body clean? Not sure, will check this.
Is the hesitation in the throttle cable or the engine picking up? It's in engine pickup. It's nothing....nothing....oops, time to wake up!
How much slack in the throttle cable? Throttle cable was extremely loose when I picked up the car. I stopped and tightened it up even before I got home, very annoying!
I like your Spit! That's on my punch list. Nearest I've come is a T-34.
05-08-2011, 11:40 AM
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Blue smoke (= oil) after engine braking usually means worn valve stem seals.
A lot of oil in the combustion process may make the engine run less responsive.
Once the new plugs are in you could do the ECU reset: cold engine, pull fuse named "BACK UP", wait 5 minutes, put fuse back in, start, don't touch throttle, don't drive, wait till cooling fan comes on twice.
I'm not sure if this fuse also messes up the radio settings.
Disconnecting the battery works to - this does mess up the radio settings.
A lot of oil in the combustion process may make the engine run less responsive.
Once the new plugs are in you could do the ECU reset: cold engine, pull fuse named "BACK UP", wait 5 minutes, put fuse back in, start, don't touch throttle, don't drive, wait till cooling fan comes on twice.
I'm not sure if this fuse also messes up the radio settings.
Disconnecting the battery works to - this does mess up the radio settings.
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