I pick up this truck last week and it runs but stalls under lead. So, I had planned several things to. One of those was to replace the O2 sensor. The previous owner just had this motor rebuilt and Im guessing put the new header/exhaust on. Well...there is NO O2 sensor or bung. This is bad right? I know with the trans am I built I had the rear O2s tuned out but still used the fronts. I probably need to get a bung welded on and put a sensor on it right?

 

So.. I know the O2 sensor shouldnt be a show stopper. I will take care of that later. However, I was trying to check/set the timing today. It was prob 20* btdc. It did not want to run at 5. I believe the previous owner added a cam with the rebuild I dont know if that may be why. I got it starting again and when I give it throttle it sticks and races the engine. I have to back it off with my hand @ the throttle linkage. When it is idling "normal" I give it 1/2 - 3/4 throttle it bogs and backfires. If I keep the throttle depressed it will die. Plans for tonight/tomorrow:

Read more in FSM about setting the timing
Replace cap,rotor, plugs, wires, fuel filter


any other ideas please?

 

Thanks for all of the input. The years of Toyota experience was invaluable on this project. For all of you on the edge of your seats wondering what the issue could be.....

It was the fuel pump. I installed a new pump along with all of the components previously removed and it runs like a top. The fuel pressure is actually too high now. It is causing the old rubber fuel lines to rupture.

Again......thanks for all of the input.

 

You're welcome.

 

I couldnt have done it without you Blue.

 

Here for you

 

I just found this post, but you saying the high fuel pressure, I have seen alot of the fuel return lines and the "J" line in the fuel tank clogged. Check the entire line as I wouldnt be surprised to see it clogged as well. I remove fuel cap and use an air hose and listen for the bubbles.
This "J" line likes to get clogged. Check all of them, but most likely this one will be clogged.

 

Damn..I hate to drop the tank again...but thanks for the info. Im replacing al of the old rubber lines this weekend. If I still have issues Ill drop the tank again.

 

Did you ever put an o2 sensor on it? Mine has the the manifold where the o2 sensor is welded up.


There is no o2 sensor at all, the plug is just hanging there.

Mines bogging down in all gears until after half throttle then it takes off. Just wondering if yours was doing that since u dont have an o2 in either.

 

I took my header and welded an o2 sensor bung. Then re-ran the wire to the ECU. My eyes dont burn with it running in the shop any more. That wasnt my issue though. It was the fuel pump and alternator.

 

Ok thanks. I got some sea foam yesterday, so I'm gonna run that through and see what happens.