engine codes and poor fuel economy (Page 1/4)
cartercarbaficionado MAY 14, 04:49 AM
finally got it to throw a code again but not sure if it's the same one I was getting at speed
I got 4 different instances of code 22 (apparently tpms for my v6) which is weird but seems to run and rev out fine and the light quickly went out after a few seconds of idling, I'll be replacing my 02 sensor since I bought a new one and don't trust the old one and this is a new tpms that I haven't calibrated yet but kinda just bent the tab until the engine would idle smoothly at 1k rpm a month ago so it's probably time I check the sensors voltage output
82-T/A [At Work] MAY 14, 08:14 AM

quote
Originally posted by cartercarbaficionado:

finally got it to throw a code again but not sure if it's the same one I was getting at speed
I got 4 different instances of code 22 (apparently tpms for my v6) which is weird but seems to run and rev out fine and the light quickly went out after a few seconds of idling, I'll be replacing my 02 sensor since I bought a new one and don't trust the old one and this is a new tpms that I haven't calibrated yet but kinda just bent the tab until the engine would idle smoothly at 1k rpm a month ago so it's probably time I check the sensors voltage output



I usually disconnect the battery / reset the codes after I've fixed things, just to make sure I'm not re-reading old codes. Have you tried doing that since you've fixed it? Were you getting any other codes at all?

I just found this on YouTube: https://www.youtube.com/watch?v=sPIPiJvt-y8


FYI: TPMS is Tire Pressure Monitoring System (for 2005+ vehicles). The sensor you're referring to is just called the TPS (Throttle Position Sensor).
cartercarbaficionado MAY 14, 04:35 PM

quote
Originally posted by 82-T/A [At Work]:


I usually disconnect the battery / reset the codes after I've fixed things, just to make sure I'm not re-reading old codes. Have you tried doing that since you've fixed it? Were you getting any other codes at all?

I just found this on YouTube: https://www.youtube.com/watch?v=sPIPiJvt-y8


FYI: TPMS is Tire Pressure Monitoring System (for 2005+ vehicles). The sensor you're referring to is just called the TPS (Throttle Position Sensor).


apparently half asleep me can't type or think lol. yeah these are fresh codes since I had just reconnected the battery after redoing all my wiring under the dash
cartercarbaficionado MAY 15, 03:52 AM
ok no codes at all but is a complete dog. gonna actually check my timing but from previous experience with this specific car if I drive it more it will get all its power back and stop having long crank times as it goes into closed loop a few times. my brakes have gone back to sucking if I downshift and let the engine scream down from 4.5k rpm after the downshift so more vaccum makes them worse.
also gonna be replacing my 02 sensor with the new walker part I got that tested out perfect in a spare car
armos MAY 22, 06:08 AM
Service Manual says Code 22 will set if the TPS signal is less than 0.2V for 2 seconds with engine running.
The signal voltage is low at closed throttle, and high at wide open.
The 1986 manual says signal should be between 0.2 - 1.25V with throttle closed, and about 4.5V when wide open. But in that video I see that version of the manual gives a different range.
Voltages can be checked with the key on, engine doesn't need to be running.

There's a 3 pin connector on the TPS. Is the connector broken? If so, make sure it's not upside down.
The outer pins are 5V (Gray) and Ground (Black). The center pin (Blue) is the signal voltage that reports to the ECM. You can check the outer pins (5V & GND) at the connector from the car while unplugged. The center wire will only have signal when it's plugged in though, so if you can't backprobe it then you might have to pierce the insulation.
Don't bend the sensor to get the idle speed you want. The TPS has only 1 specific job and just needs to report the correct information. Use a multimeter to measure it. Voltage should steadily increase as you open the throttle, within the range described above from the service manual.

If you have intermittent random sensor problems then it could be caused by damaged wiring. If the signal wire is shorting to ground, or if it's frayed somewhere and losing contact, then it would cause this code. If the 5V line is failing it might have a similar effect. 5V is provided by the ECM, there are multiple sensors and the ECM itself that rely on the 5V supply, not just the TPS.


If you can set yourself up with WinALDL on a laptop, you could monitor the sensors while the car is running and get a better look at everything the ECM is seeing.

[This message has been edited by armos (edited 05-22-2024).]

Jason88Notchie MAY 22, 10:39 AM
Yeah. Everything armos said with TPS. And while the scanner is on, check IAC COUNTS with engine running. Make sure engine is at running temp. Should read close to 50 counts.
cartercarbaficionado MAY 22, 05:01 PM

quote
Originally posted by armos:

Service Manual says Code 22 will set if the TPS signal is less than 0.2V for 2 seconds with engine running.
The signal voltage is low at closed throttle, and high at wide open.
The 1986 manual says signal should be between 0.2 - 1.25V with throttle closed, and about 4.5V when wide open. But in that video I see that version of the manual gives a different range.
Voltages can be checked with the key on, engine doesn't need to be running.

There's a 3 pin connector on the TPS. Is the connector broken? If so, make sure it's not upside down.
The outer pins are 5V (Gray) and Ground (Black). The center pin (Blue) is the signal voltage that reports to the ECM. You can check the outer pins (5V & GND) at the connector from the car while unplugged. The center wire will only have signal when it's plugged in though, so if you can't backprobe it then you might have to pierce the insulation.
Don't bend the sensor to get the idle speed you want. The TPS has only 1 specific job and just needs to report the correct information. Use a multimeter to measure it. Voltage should steadily increase as you open the throttle, within the range described above from the service manual.

If you have intermittent random sensor problems then it could be caused by damaged wiring. If the signal wire is shorting to ground, or if it's frayed somewhere and losing contact, then it would cause this code. If the 5V line is failing it might have a similar effect. 5V is provided by the ECM, there are multiple sensors and the ECM itself that rely on the 5V supply, not just the TPS.


If you can set yourself up with WinALDL on a laptop, you could monitor the sensors while the car is running and get a better look at everything the ECM is seeing.



my voltage range is 0.35 volts to 5volts so I'm pretty sure it's fine and it has a new connector that works, I did have to bend the tab and tighten the arm attached to the throttle plate to make it read properly
cartercarbaficionado MAY 22, 10:42 PM

quote
Originally posted by Jason88Notchie:

Yeah. Everything armos said with TPS. And while the scanner is on, check IAC COUNTS with engine running. Make sure engine is at running temp. Should read close to 50 counts.


yeah no idea. timing isn't my issue and I thought that was it so I'm out of ideas
Jason88Notchie MAY 22, 11:20 PM

quote
Originally posted by cartercarbaficionado:

yeah no idea. timing isn't my issue and I thought that was it so I'm out of ideas



You need a scanner. Your flying blind. Do like armos said and get WinALDL. Or find a hand held that will read OBD I.
cartercarbaficionado MAY 23, 03:29 AM

quote
Originally posted by Jason88Notchie:


You need a scanner. Your flying blind. Do like armos said and get WinALDL. Or find a hand held that will read OBD I.


I'm not flying blind. I have a vauge idea of what could be causing this but everything checks out which tells me it's something much much more dumb. I haven't put a vacc gauge on it yet to see if maybe it's valve related because it could be but I'm not sure if that would cause the random loss and gain and power and the poor fuel economy. I thought i set the valves right but maybe I didnt?