Are they really that hit or miss when you buy them?

Anyhow, this is now my 3rd one in 2 years. I just replaced it on Sunday, and that one Just died. Worse yet - it wasn't even a cheap chinese part. Well, hopefully its a defective part and not a trend.

Symptoms: Started backfiring on the way home, and now it seems to be dead (truck wont start/run unless I have my foot on the gas). Same symptom I had Sunday and was fixed when I replaced it. The truck drove home, but the minute I turned it off, it wouldn't start or run without a foot on the gas pedal. Took it back to the store, got a new one and it seems to be running again.

I'm just looking to see if anyone had a few of these go bad and if they were symptomatic of a larger problem.

I did have both O2 sensors disconnected, because I was trying to solve a backfiring problem (which turned out to have been the TPS which is why I replaced it on Sunday).

98 dodge ram 1500 5.9 Plenum was done prior to me buying it (3 yrs ago).

 

What brand are you using?
Standard Motor Products stuff seems to work well on these trucks as well as BWD.

 

It was actually an SMP sensor.

 

Odd, several members swear by SMP. Have you actually tested the sensor to make sure it's the sensor and not the wiring?

 

how does one go about testing one of these?

 

Multimeter for sure, I don't remember the procedure though.

 

From service manual
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
PCM) represents the throttle blade position. The
PCM receives an input signal voltage from the TPS.
This will vary in an approximate range of from .26
volts at minimum throttle opening (idle), to 4.49 volts
at wide open throttle. Along with inputs from other
sensors, the PCM uses the TPS input to determine
current engine operating conditions. In response to
engine operating conditions, the PCM will adjust fuel
injector pulse width and ignition timing.

Dave

 

with tps installed and electrical connector attached, you can probe the electrical contacts with a multimeter. if you don't have skinny probes, you can insert small nails or paper clips to reach the contacts, and then probe those.

i've replace mine about 3 times in 5 or 6 years.
i had a 87 or 88 dodge caravan that used to eat them and need replacing about once a year.

if you haven't done so yet, get your next one from someplace local that offers a lifetime warranty - Advance or Autozone.

 

Damn - this new one seems to be DOA, as well. Another SMP.

I would think its a harness issue, except for the fact that putting in a new sensor makes the truck start and run smoothly - like it was brand new. That's what has my confused. And each of the "bad" sensors had slightly different symptoms - they didn't all do the same thing.

I have a multimeter. If I know what the values should be, I can check it.

Symptoms:
Original Sensor - 1 yr old - backfires under acceleration - truck runs, but surges and if I rev engine at idle, it'll bog out and stall.
New Sensor 1 - 2 days old - ran perfect for 2 days, then backfired under acceleration on way home from work - truck wouldn't start again.
New Sensor 2 - 5 minutes old - backfired under acceleration on the first trip. pulled into my driveway wouldn't restart. disconnected sensor and removed it to look at it, reinstalled it, and it starts, but will again backfire under acceleration and then won't restart.

It could be a harness issue, but why would replacing the sensor make it go away for a day, two, or 10 minutes? I tried moving the harness a little to see if I could make the problems go away or make them worse - just to help try and rule it out - made no difference.

 

Three wires on the sensor connector, 5 volt source, signal return to PCM, and ground. I think the center wire is the signal return.

Verify you have five volts on the source wire.
Probe the signal return wire, value should be under 1 volt with throttle close, and increase SMOOTHLY up to greater than 3.5 volts at wide open throttle. If it bounces around, or isn't in the acceptable range, it's bad.

Best to use an analog multimeter for this test, so you can actually watch the needle sweep. Digital meters don't react as quickly, and its really hard to get an accurate test.