Hey, I have a Chevy truck with a 350/5.7L in it and it is Throttle Body Injected and it has no ***** anymore and it idles ****ty and at about 1100 rpms it bogs and almost wants to stall. The acceleration is terrible the trans shifts with the correct rpms but I have to pretty much punch it to go anywhere.

I replaced:
TPS (Throttle Position Sensor)
Distributor, Cap/Rotor
Cleaned the Throttle Body
PCV Valve
Fuel Filter
Plugs
Wires

and I also did the timing.

The only thing I think it could be is a worn timing chain but I don't know any of the symptoms of that.

Does anyone know what my problem might be and how to fix this? I would be much appreciated.. thanks in advance. =)

 

To check for a worn timing chain put a timing light on it and see if the mark jumps around. Also have you tried 02 sensor? Whats your fuel pressure?

 

Haven't checked the fuel pressure or the O2 sensors yet... But the mark isn't too steady. So it could be the timing chain.. has 123k miles.

 

You put a timing light on it already? If so how much was it jumping? Another thing you could check is the lift on each of your rockers to see if your cam is worn out.

 

Yeah, I the timing light and moved it to top dead center. I did advance it a little before but now that it is top dead center it seems like its running a little ****tier. The line was jumping probably a 1/4 inch at most.

 

Ok let me ask you this when you adjusted the timing did you unplug the timing bypass connector underneith the glovebox?

 

Nope.

 

Thats why you are doing nothing to the timing without unplugging this!! Do this turn truck off unplug the wire in the picture below. Start truck adjust timing to 0 degrees BTDC! Tighten distributor recheck to make sure it did'nt move! Turn truck off unplug battery to clear check engine light, plug timing bypass wire back in, replug battery in then see how it runs! Got it?

 

Got it. But there is no pict. It is just the smaller looking plug on the ECU right?

 

It is tan wire underneith the glovebox. It has a black plug on it. YOu can not see the pic? I see it now.