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Hesitating throttle

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Old 01-09-2017, 12:48 PM
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Car: '02 Z06
Hesitating throttle

89 Iroc 305 TPI, auto, 50,000 original miles.

car has good power, runs good, no check engine light. But when I first take off from a light It takes a second after I hit the gas for the motor to respond. Where should I check first?
Old 01-09-2017, 01:00 PM
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Hesitating throttle

You might want to first sweep your tps.
If you have the stock multec grey body injectors you might want to replace them. Southbayfuelinjectors has the ne'er Bosch 3s.
Sweep testing

Probe the dark blue signal wire with your multimeter with the key on. you should see .54v -.57 .

if you are not in that range then you have to do 1 of 2 things.
if your TPS is adjustable (bolt holes slotted for movement) then you need to adjust the reading to above before continuing the test.
If you have a non adjustable (auto zeroing) TPS then you are in need of a new sensor.


Sweep test: Now you need to probe the signal wire with the key on while very very slowly opening the throttle. AS you give more throttle the voltage will start to increase. You need to watch carefully for a smooth, glitch free raise in voltage. If at anytime the voltage make a large jump, a large dip, drops to zero or jumps to above 4 volts the sensor is bad. Continue the sweep test until you have reached wide-open throttle at which time the voltage should read over 4 volts.
Old 01-09-2017, 01:46 PM
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Re: Hesitating throttle

I actually tried the TPS, and I could not get a voltage reading at all. I double check that I was doing it properly several times
. Here's a picture of mine
Old 01-09-2017, 02:11 PM
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Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Hesitating throttle

Key on engine off you can back probe with a paper clip. Grey wire should be around 5v D.C.
The blue wire is feedback to the ecm. This is the wire you want to slowly open the throttle looking for spikes or loss of voltage.
Old 01-09-2017, 07:23 PM
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Re: Hesitating throttle

sounds a lot like a failing maf sensor




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