Well its not the timing. that is all done now, still the same. not as bad because the dist. it tight now. going to do the fuel pump today

 

i have a 02 z71 code knock sen bad has lost power and runs hoter now is sen under intake and what will my chev dealer charge

 

OK so it is not the fuel pump either
.
AAAAAHHHHHHHHHHH

HELP, what else to try?

 

It still sounds like a fuel delivery problem. If you havent done so already, i'd check the fuel pressure. Your truck doesnt have a fuel rail, so you'll probably have to remove the filter and put the gauge in its place. Or just replace the pressure regulator in the tbi unit altogether. Depending on how many miles you have on it, it may be getting close to time anyway. A whole kit with all new gaskets can be had for about $65 or less at a parts store. Of course, i swore my problem was fuel related, and it turned out to be a faulty spark plug wire that was brand new. So it is possible its electrical, but see what the pressure is. How many miles are on the motor? Will it miss and stumble if you rev it in park, or only under load when driving?

 

There are about 125,000 Km on the motor/tranny.
Only stumbles with a load

I will see what I can do with the pressure

 

Yes pressure is good.
tried something last night. unplugged the coolant temp. sensor. that way the truck believes it is always cold when driving, and it drove great!!!
does this help?

 

I changed out the fuel pressure regulator, will find out in the morning how it is. I will replace coolant temp sensor if it doesn't

 

ok so the fuel regulator did not change anything.
I changed out the coolant temp sensor at lunch, will have to wait until the drive home to see if it has made a difference. the connector on the old one broke off real easy when removing it, so cross my fingers for me

 

Interesting. Without the coolant temp sensor, your trucks computer is operating in open loop, meaning it is not using the signal from your o2 sensor. When you start the truck cold, it runs in open loop until your engine temp hits about 150 degrees. Disconnecting it should have made your truck run like crap when its warm. The temp sensor is the cheaper fix, hopefully it works, but if not, i would definetely look at the o2 sensor. Either it would be sending a corupt signal for some reason (old, worn out, clogged, bad wire) or the ECM is messed up in its programming of what to do with that signal. Its odd you wouldnt get a code for that though. At any rate, good luck.

 

The Temp sensor did throw a code when unplugged, but I ignored it because I forced it.
AND THE TRUCK IS FIXED!!
Turned out it was the temp sensor!!!! ran great last night after I changed it at lunch and ran great this morning!!! right on, very happy guy here today!!!
I have an O2 sensor in my bag of tools, took one from the local pick a part junkers. just in case. I wil hold onto it for now.

Thanks to everyone who offered their help. This site is great.