I just bought a 1996 SR with a few problems and hope that I can slowly get it running right. It has been to three shops, but, no luck.

It runs awful, missing, black smoke, no power most of the time. It will run fairly well then just looses it. The only problem that they could find was excessive leak down in the cylinders, but couldn't explain why it would run so erratically. I changed the O2 sensors, plugs and they say that they tested everything else. It shows a PO300 code, which doesn't say much. I know that I'm due for an overhaul, but, can't do it right now, so, hoping to get it to run better for now.

When it's running good, about 25% of the time, it goes.

I'm trying to eliminate things that don't seen right to me one at a time. The engine (3.5 DOHC) has 4 temperature sensors (I'm assuming), two forward and two aft of the front two, but only the right/rear and left/front are connected, the other two are not. Is this how it supposed to be? I cannot find any wires/connectors anywhere that looks like they belong to them. I tried to attach. a photo, hope it shows.

I really like this truck and hope to get some help in getting it going.

 

Why is it that I can't get help with my posts? Is it the way that I'm doing it? I have posted to several different forums and yet to get a reply.

If I'm doing something wrong please let me know. Any and all help would be greatly appreciated.

Thank you.