intermitting sputtering on 1/2 throttle

[Whip]

1st: im getting a skipping or kinda like a bucking about 1/2 throttle. kinda like a plugs is going out or like it is starving for gas. then i put my foot to the floor as it is still skipping then it just clears up till i go 1/2 throttle again. it was running fine yesterday till i changed out the ect and tps i also put on cat back dynomax exaust cleared out the computer and reset the idle. but i get codes. here they are 118 ECT indicated -40degF. Circuit open. and 122 TP sensor circuit below minimum voltage on koeo but i get no codes and a 111 on koer and i made sure the car was up to operating temp on both tests.

2nd: last night when i ran the test i got the same 122 code but i got a 114 ACT out of self-test range also and a 111 on the koer test

could the ect and the tps i got from auto zone be bad ? any ideas on were to look would be a help thanks

 

[SASHO91]

if the ambient temp is below a certain temp it will throw that code I believe.
Is this while in like 5th and the engine loaded? if so i'd look into some new plugs/wires.

 

[Whip]

nope i forgot to mention it does this in all gears!!!!! plus i have recently put in new plugs,wires,maf,act,fuel filter and fpr! so as of now all i have left to check is fuel pressure. but i dont think it is the pump. i think it has something to do with the new sensors cause it ran fine till i changed them!

 

[SASHO91]

then uh... why did you change them

If it does it in all gears, i'd say give the maf a cleaning (i know its new) just incase.
Sounds as if its an A/F problem. If it were a spark problem it would show itself by doing it when under high throttle high load applications (going up a hill in 5th gear with the pedal at 1/2)

you sure you put the fuel filter on right?

 

[Whip]

yup i did put it on right gonna try the maf


thanks

 

[Whip]

still does it but i notice it more on empty tank. wonder if it could be the pickup ? or pump?

 

[jedhead]

still does it but i notice it more on empty tank. wonder if it could be the pickup ? or pump?

You may have some bad gas at the bottom of the tank.

Bob

 

[Whip]

was thinking of that to put some dry gas in still the same! now it seems to do it when i go thru the gears up to 7,000 rpm then drive normal and it starts doing it about 1/2 throttle. it was fine till i put the tps and the ect sensor in it has never done this before it also seems to run fine till i go over 1/2 throttle
check for codes but all i get is the 118 and 122. and other ideas would be greatfull!

 

[SASHO91]

you could have a flat spot in the TPS sensor... try swaping it out.

 

[jedhead]

118 The ECT (Engine Coolant Sensor) sensor was above max voltage or -40F or below coolant temp
122 TPS sensor circuit below voltage.

The ECT thinking the engine is cold will cause the car to run rich. Since you are getting codes that has to do with the parts you replaced, something was installed wrong or the part installed is bad

Bob

 

[Whip]

thats what im thinking jed! but i had sooty tailpipes and i only got about 200 to 250 miles to a tank of gas and i read on a couple of forums threads that the ect being bad would cause this. i did not have any codes saying anything was wrong with anything on the car i just assumed that they just were bad and being cheap enough to replace i figured i would replace them and maybe help on the gas mileage. im gonna check the tps sensor for flat spots and just go back to autozone and get a new ect sensor and see if that fixes it. is there anyway to test the ect sensor to see if is bad ?

 

[SASHO91]

get the car up to temp, pull the connector out, and check resistance. Im not sure of the exact resistance you should see.... but IIRC, that sensor is only on a 0v-5v scale, but dont qoute me.

But before you do that, one question.... When you pull the codes, is the car up to running temp (or atleast past 160*), if not then THATS why you are getting the ECT code. If thats the case, dont worry about getting another sensor, your problem lies elsewhere.

 

[40BelowSummer]

get the car up to temp, pull the connector out, and check resistance. Im not sure of the exact resistance you should see.... but IIRC, that sensor is only on a 0v-5v scale, but dont qoute me.

FYI Resistance is measured in Ohms whereas voltage is measured in volts.

I'd test the TPS make sure it has a linear voltage of about 0-5V. I'd also test the fuel pressure and grounding system (intake ground).

 

[SASHO91]

yeah i know...

I was thinking too fast..

what you could do, is back probe one of the wires, and see what the voltage is at as well (while the car is in KOEO.

 

[jedhead]

at 68F the resistance between the two contacts on the ECT should read 37,300ohms. As the temperature increases the resistance will decrease.

Bob

 

[Whip]

ok i will try all that and post the results

thanks guys