Fixes for sensor malfunction on '88 T4R

[Dan98034]

I just inherited my T4R from my dad, he said that the sensor mounted under the intake manifold had been replaced as the computer was throwing codes and retarding the timing.

When I am running on the highway,I rarely have problems, but city driving and getting off the highway causes the computer to throw codes.

How can I fix this or where is a thread that can help me. I am tired of having to cycle the ignition when the check engine light comes on.

Thanks!

 

[KidVermicious]

Need WAY more info. Is he talking about the knock sensor? What engine is in the truck? What codes are being thrown?

 

[crutchy]

Sounds like he is talking about the knock sensor. FWIW Dan those things rarely go bad, 90% of the time it is the wire which you can pick up from Toyota for about $15-20. Mine had this problem when I picked it up and the PO had tried to adjust the timing to compensate. If it is the knock sensor, from what I found you have 2 options:

1. Pull the intake and replace the pigtail wire
2. Find a spare knock sensor at your local pull a part and mount it on the rear engine lift hook with a new pigtail wire. Not the most popular, but it works.

Either way check the timing afterwards, and good luck.

 

[maco33]

Also you can test and adjust your TPS, that might be the problem.

 

[Dan98034]

Need WAY more info. Is he talking about the knock sensor? What engine is in the truck? What codes are being thrown?

Sorry, yeah, it's the knock sensor on a 3.0, I don't recall what the code is that it is throwing.

 

[Dan98034]

Sounds like he is talking about the knock sensor. FWIW Dan those things rarely go bad, 90% of the time it is the wire which you can pick up from Toyota for about $15-20. Mine had this problem when I picked it up and the PO had tried to adjust the timing to compensate. If it is the knock sensor, from what I found you have 2 options:

1. Pull the intake and replace the pigtail wire
2. Find a spare knock sensor at your local pull a part and mount it on the rear engine lift hook with a new pigtail wire. Not the most popular, but it works.

Either way check the timing afterwards, and good luck.

Yeah, we tried both options and neither one fixed the problem.Well check to see if timing has been fixed

 

[crutchy]

If you can pull the code and let us know of any other symptoms it would be helpful.

 

[Dan98034]

Ok, the knock sensor is the code that is popping up even with a new sensor and pig tail. So we are thinking it is a wiring issue with the harness from the pig tail to the computer.