Okay has been a little while sense I have been on here. Work... Still working on getting my blazer running again after it's failure... Still not sure of whats wrong but it won't idle very well and wants to stall out. This all came about all of the sudden and coded lean fuel. I have sense replaced the base gasket, air mixture valve, inspected all the hoses and finally after soaking it with kroil and pb blaster got the o2 sensor out. (Cold) I was happy that it finally came loose. When I attempted to install the new one it would not start in it's manifold threads. Further inspection? the threads are gone on the old sensor and a mess on the manifold. Any suggestions on how this can be remedied without removing or replacing the manifold? I was so very careful removing that dang thing. All thats left after installing the new one is to replace the ecm? I have purchased it already just wanting to do one thing at a time. I love this rig and would love to keep it original and get everything working. Headers and dual exhaust may be in the works if this doesn't work.

Any help or suggestions would be greatly appreciated...

 

I think Napa sells a tap that can be used to clean up the threads in the manifold

its a common problem ... happens sometimes even with lots of heat

 

Thank you for the info, I was looking for it on line and the tool is available and costs around 6 bucks. I have to order it though, more waiting. I am doubting this will fix the problem but it can't hurt. It certainly does not lack for getting fuel though.

 

Well, got the O2 sensor out finally. Ordered a thread chaser to fix the threads and installed new sensor. Still codes 44 and i have a little less hair now. lol. I have replaced every sensor there is and have a new ecm but doubt that is the problem... I bought some high octane fuel and moisture remover suspecting there may be some water in the system? This truck sits a lot. The exhaust smells funny. Not like a bad cat just sour fuel? What is my fuel pressure supposed to be? And what tool do I need to check it? I looked at fuel pressure gauges at advance but they are for carbs with superchargers or double pumpers. I may end up buying a new fuel pump and filter in the end. One last thing? fuel seems to bead up in throttle body like water beads up on oily surfaces, is that normal? Oh just give me a carburetor! LOL

 

Which engine do you have 2.5 L4 or 2.8 V6? When you turn the engine over what does it do?

 

wow, i really did not mention that it is a full size K5 Blazer with a 350 TBI. I am loosing my mind. I do realize without all the information I am shooting in the dark. I have a feeling it is either the fuel pump or the filter though.

 

oh! and it will not idle and at half throttle runs rough. both disappear if I spray fuel into the throttle body.

 

Check to see how much fuel your getting via a pressure gage or by disconnecting the line to the TBI and turning the key to on and not starting. Also check for a vacuum leak and that your plug wires are installed in the correct firing order.

 

I'm not that familiar with what you have but in that situation I'd likely start with the cheaper-easier fix and try replacing the fuel filter. If it's been a while it sure doesn't hurt to change it even if it doesn't fix the problem.