Throttle body issues

I've seen the flashing lightning bolt a few times since I bought my truck. It usually does it when there's water around, but the last time it did it, I was just pulling out of Burger King. Killing and re-starting the truck has fixed the problem every time.

I hooked my scanner up to it and got a rather strange reading. There are 2 TPS readings and 2 rpm readings. One has a 18 next to it and one has a 10. I've never seen that on any other vehicle I've hooked my scanner to. The scanner says mod 10 is unresponsive and the tps reading with the 10 next to it reads 0.0. Both RPM readings are not the same at all times. They are close so I assume it's my older scanner just being a bit slow. The other thing I find strange is when you floor it, the TPS only reads 86.3%. I once got it to pop up to 93% but it immediately went back to 86.3.

It runs kinda glitchy too. Between having the gas pedal mashed half way down to almost all the way down, it runs very rough. The trans downshifts like it ought to and all, but the truck either surges when it accelerates, or it flat out doesn't accelerate at all until you floor it or let up off the gas till it's less than half way to the floor. Flooring it 100% seems to make it run right, but anything less than all the way to the floor and it screws up.

You can remove the gas pedal and validate the contacts on the potentiometer. Through using a multimeter tester, validate the variance is smooth throughout the operating range of the pedal.

Check all the contacts on the connectors, check the wiring, also make sure all the grounds are A-OK. The drive by wire vehicles are far more sensitive to bad grounding. Check the PCM connections/wiring harness. Check the IPDM (Fuse box near the battery on the driver side under the hood). The main positive connection tends to get very corroded and a good cleaning may restore good power to the electronic systems.

If none of that works, you could try and find a salvage yard TB and see if replacing it solves the problem. If you have a good friend with the same truck, you can to swap your TB for his for a few minutes strickly for troubleshooting purposes.

Hope these few things help guide you in the right direction.

That does help, but I think I definitely have a TB issue. It was nasty and gunky when I bought the truck so I cleaned it... with TB cleaner.... I hear that's a real no-no. I don't think it had a problem before that

Rumblebee said:

That does help, but I think I definitely have a TB issue. It was nasty and gunky when I bought the truck so I cleaned it... with TB cleaner.... I hear that's a real no-no. I don't think it had a problem before that

Click to expand...

Cleaning the TB is OK if done properly. If you sprayed everything indiscriminately then yes you probably damaged it. I always take the conservative approach and moisten a rag with the cleaner and use some elbow grease. The backside of the throttle plate is what needs the most cleaning.

This thing had a 1/8" layer of gunk around the entire bore of the TB. It did take a good soaking and scraping with a flat head screwdriver to get it remotely clean. I almost forgot to mention, it's extremely sluggish to react to sudden acceleration. Trying to punch it through a yellow light is nearly impossible. My DBW Silverado does that, but it's only sluggish to downshift. The TB opens immediately as soon as you floor it.

got to be joking

Rumblebee said:

This thing had a 1/8" layer of gunk around the entire bore of the TB. It did take a good soaking and scraping with a flat head screwdriver to get it remotely clean. I almost forgot to mention, it's extremely sluggish to react to sudden acceleration. Trying to punch it through a yellow light is nearly impossible. My DBW Silverado does that, but it's only sluggish to downshift. The TB opens immediately as soon as you floor it..

Click to expand...

you scrapped it with a screwdriver to clean it?! wow lol had to of left scoring on it. I used a toothbrush.

Yeah I had tried a stiff bristle brush but it did nothing. This stuff was like hardened gunk. Anyways, I got under there and I'm extremely confused. It's not like a Chevy with the potentiometer mounted to the gas pedal, it's under the hood under the battery. How do I go about checking that thing? I also seafoamed it and noticed it can't hold a steady rpm even if you have the gas pedal mashed down with a fixed object. It sits there and fluctuates up and down a few hundred rpm and sounds like an old pos Honda with a bad idle control valve.