I've noticed for a few months that my truck doesn't like the rain or snow. It tends to idle very sporadically in park and especially when at a stop light. It also hesitates in rpms up to about 45mph. From what I've gathered on here, it could be the TPS or a bad/wet cap and rotor. The cap and rotor were new when I swapped engines in the fall, but could them being wet just be my problem?

I also hooked up my TPS to a volt meter last night and got some unusual readings. I took the sensor off to do it and was getting a reading of 5.10 to 3.5 to 0.01 and kind of all over the place. I read different threads about how to test the TPS and followed them pretty accurately.

What do you guys say? Thanks.

 

If the signal voltage from the tps is bouncing around, it's bad. Replace it.

How old are your plug wires??

 

You need to test the TPS with an ohmmeter, it is a potentiometer, it increases and decreases resistance to give the computer the proper throttle reading. Hook up your multimeter to it and then turn the TPS, the resistance should increase evenly. If it has a bump or if there are any jumps to an open circuit it is bad and needs to be replaced.

 

HeyYou the wires, plugs, cap and rotor are all new as of October. Along with head gaskets, plenum, intake, blah blah blah haha. I bought a new sensor, I'll see if it does anything tonight.

 

Replaced the sensor and I thought while I was in there I would put on my new 52mm throttle body. I drove her pretty nicely the whole way home from the shop but noticed that when I came to a stop it started sputtering and had a real loud hiss-like sound from the hood. This is what was happening before I replaced the sensor, so I don't think that's it? I reset the PCM for the new TB as I was told and then reloaded the 91 tune from my SCT. Any more suggestions?

 

How's fuel pressure?

 

Not sure, how would I check it?

 

Need a gauge. Can get one at the parts store for reasonable. Or maybe even rent one.... Should be a schrader valve on the drivers side fuel rail you screw it to.

 

Ok, well I'm probably goin back out to the shop late tonight to work on my riding mower project and I'm sure the guys have the gauge. Will update when I can.

 

Didn't get a chance to read the fuel pressure, but I did notice that every once in awhile while driving, when I came to a stop it felt like I had the foot on the accelerator and the brake. So I put her into neutral and it was idling at like 2k. I shut it off and started it back up and it was fine. Happened to me twice in like 30 miles.