water temp sensor causes header to glow

[geeknahalf]

Hi Folks,

I'm stuck.

I have a 2004 jeep wrangler TJ, and I recently built a 4.6 stroker and I'm experiencing an odd issue. When i plug the water temp sensor in (it's a new unit), it runs great for about 5 minutes then goes down hill. The eng runs rough, stumbles, gurgles in the muffler, runs like crap, has zero power, and the exhaust glows red. In essence, it's completely undrivable. I have a lot of money tied up into this and don't want to ruin it.

I have replaced the entire exhaust so no restrictions there. Its a 99 wrangler exhaust which only comes with two O2 sensors, so I relocated the remaining O2 sensors required for the 04 next to the factory locations on the 99 system, upstream/down stream respectively.

The timing is set properly as far as I can tell- on TDC compression stroke and the cam sensor lines up according to the alignment tool (no hole to use, they include a cap that aligns the placement)

If i unplug the coolant temp sensor the jeep drives enough that i got it home from the mechanic shop, and the exhaust doesn't glow. They couldn't determine the cause...

I'm sure there's information I'm forgetting, but I'm at such a loss and burnt out that I cant think straight so please ask questions.

Before I made the swap, the jeep ran great.


Any guidance would be greatly appreciated.

Me

[mpgMike]

This is an old post, but I know folks use the "Search" feature when they have issues, so there may be some that find this post wanting answers. To me the answer is probably a CTS (Coolant Temp Sensor) with different calibrations. I have a '95 ZJ, so I have the '95 Service Manual. However, it outlines what the resistance value should be at various temperatures. A good test would be to find that chart for your 2004, measure the resistance across the CTS and see if it's any near what the FSM chart states.