Hello, I just finished a month long head gasket change on a 96 t-100 with the 3.4l 5vz-fe v6 auto tranny. It now will not find idle. In order to get it to start I have to feather the accelerator peddle. But once I turn on the A/c or hold it at about 1000 RPM it will find idle and hold/correct it in and out of gear and with and without the A/C on. I think I have all the vacuum lines on correctly but its been 4 weeks since I last saw the engine assembled. Any ideas or vac line diagrams? The FSM shows them but not in great detail.

P.S. The truck also has no EGR...

 

did you hot tank the intake manifold? check the tps readings.

 

I sandblasted and throughly cleaned the many little channels in it. I will check the TPS signal, should be about 5v at WOT?

 

I'm not sure on the readings you'll have to check the fsm. Maybe something is up with the throttle. Do you have a obd2 scanner? Check for codes and check to see what the coolant temp sensor says.

 

I do have a scanner and will check for the coolant temp sensor to show correct readings. No check engine light, maybe hidden codes. Spent 2hrs flushing very rusty coolant. It slowly started working better but is far from correct. I notice if I push the a/c on button it immediately starts working and I can let off the throttle.

EDIT: Thanks for the speedy late night replys

 

there is a coolant passage in the throttle body that also deals with idle. you maybe want to pull the throttle off and carefully clean it.

 

BUMP

 

Sure the intake gasket didnt slip out in a spot or two when you put the intake on? Could be pulling air around that.

 

95ImpySS- Did you ever figure out what the problem was/is? Is it fixed?

-Chris