Timing 5.0 & TPS Testing
#1
02-02-2015, 10:53 AM
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Timing 5.0 & TPS Testing
Truck: '93 F150 5 liter engine code N, 2 wheel drive
I am having real problems with this truck When checking the TPS resistance the manual and the sensor wiring don't match up. The ref, grd, & signal wires seem to be in wrong location. I have bought 2 sensors and they are the same as the one in the truck, which looks aftermarket.
I am using 2 different Haynes manuals and they show the connector and Values as the same.
Also I had to replace the Dizzy because the bearings were screaming. I set the initial timing at 10 deg BTC, with the "SPOUT" out. With it connected I am getting a timing of 20 deg BTC Is this normal?
I am having real problems with this truck When checking the TPS resistance the manual and the sensor wiring don't match up. The ref, grd, & signal wires seem to be in wrong location. I have bought 2 sensors and they are the same as the one in the truck, which looks aftermarket.
I am using 2 different Haynes manuals and they show the connector and Values as the same.
Also I had to replace the Dizzy because the bearings were screaming. I set the initial timing at 10 deg BTC, with the "SPOUT" out. With it connected I am getting a timing of 20 deg BTC Is this normal?
#2
02-02-2015, 04:24 PM
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That threw me off too. I found out that testing resistance between vref and tpsig seems to match up with the haynes manual. SeattleFSB has posted this in his tps thread on fullsizebronco.
Link to thread Throttle Position Sensor Testing, Replacement and Adjustment - FSB Forums
Link to thread Throttle Position Sensor Testing, Replacement and Adjustment - FSB Forums
TPS Resistance Testing is normally done on the unplugged TPS on the TPS SIG and VREF wires. You are looking for resistance values of <4k ohms at closed throttle and >350 ohms at WOT.
When testing resistance on the TP SIG and VREF wires, the resistance will decrease.
When testing resistance on the TP SIG and SIG RTN wires, the resistance will increase.
This is due to the design of the sensor and direction of the internal "wiper" that mechanically changes resistance. Depending upon which side of the TP Signal wiper you are testing (VREF or SIG RTN), the resistance will either decrease or increase with the counter-clockwise rotation of the sensor. The specification listed is for the VREF decreasing value.
Although resistance can tell us the condition of the sensor, our end goal is always the resulting voltage range being processed by the EEC.
For more TPS information, see this link: Throttle Position Sensor Management
When testing resistance on the TP SIG and VREF wires, the resistance will decrease.
When testing resistance on the TP SIG and SIG RTN wires, the resistance will increase.
This is due to the design of the sensor and direction of the internal "wiper" that mechanically changes resistance. Depending upon which side of the TP Signal wiper you are testing (VREF or SIG RTN), the resistance will either decrease or increase with the counter-clockwise rotation of the sensor. The specification listed is for the VREF decreasing value.
Although resistance can tell us the condition of the sensor, our end goal is always the resulting voltage range being processed by the EEC.
For more TPS information, see this link: Throttle Position Sensor Management
#3
02-02-2015, 06:52 PM
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That's great. Just what I was finding. I replaced a coolant temp sensor, a brake switch and found the EVAP purge valve installed backwards. Balance is good. The only codes I have left are 12, 13 & 77. Both to do with Idle control,can't figure what went wrong operator error. I am not going to take on trip tonight like I wanted. So I will have to look into it in a couple of days. Any suggestions??
#4
02-02-2015, 07:47 PM
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It MIGHT be a user error code. When I have done the KOER test. Ill let the CEL do it's thing and when it blinks the last time. I steer left/right, push brake pedal and floor the truck. Try that and see what happens. Probably don't have to steer left/right if you don't have a psi sensor on the high side power steering line.
#5
02-06-2015, 06:44 PM
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Operator error was that I did not press gas pedal after single blink.
I am still getting 12 & 13 codes. Idle is high. How do you set the air gap for the throttle plates in the throttle body? I can raise the idle but not lower it. Not much in manual to cover this.
Also I had to replace the Dizzy because the bearings were screaming. I set the initial timing at 10 deg BTC, with the "SPOUT" out. With it connected I am getting a timing of 20 deg BTC Is this normal?
I am still getting 12 & 13 codes. Idle is high. How do you set the air gap for the throttle plates in the throttle body? I can raise the idle but not lower it. Not much in manual to cover this.
Also I had to replace the Dizzy because the bearings were screaming. I set the initial timing at 10 deg BTC, with the "SPOUT" out. With it connected I am getting a timing of 20 deg BTC Is this normal?
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