I replaced my Castech heads this past weekend with another pair of stock heads.

I noticed today that when I come to a stop light it feels like the truck wants to stall and then catches itself.

Any help would be greatly appreciated as to what might be causing this, I did replace the plugs and wires while I had it apart.

Thank you for all your help.

 

What casting number are the heads that you replaced them with? 862?

 

could be a tune related problem. if you didnt change the tune and it was a maf tune the calculated and recorded airflow will not match and the pcm will need to make changes over time and idle out but with new heads you may need to adjust your tune.

 

Sorry I replaced the factory 706 with 862 so this should not be a tune related problem.

I was thinking about lossening the intake and trying to resettle it and retorque it, as close as I can get to 89 inch lbs, or near 8 ft/lbs my smallest wrench goes to 10.

Would and exhaust leak cause this kind of issue, I had a header bolt break while reinstalling, it was not cross threaded but get tight, not sure if I put too much of an angle when I tried to remove it but it broke off at the mounting flange of the exhaust manifold. I am not hearing a leak up in that area but I am not ruling anything out.

This is the second to the last bolt on the passenger side.

No check engine light either.

Thank you again for any insight.

 

What was wrong with the old heads? There had to be a reason you replaced them. If you had replaced a good set of heads with another good set of heads it could be the intake gaskets. Spray around the gaskets with starting fluid.

 

I had the Castech heads that were leaking coolant into the heads. I was losing coolant and oil, oil was due to valve seals and I am guessing the PCV sucking it into the intake.

The valve covers were filled with butterscotch looking jelly.

 

Engine is now giving p0300 codes and is getting progressively worse in its running, and the check engine light will flash while under acceleration, such as on an on-ramp.

I had loosened and re-torqued the intake lastnight and they may have made things worse.

I am guessing I need to pull the intak off again and see if there was any damage to the new gaskets.

Again I appreciate any help I can get.

 

Give the plug wires a check while you're under the hood. If they don't get put on fully, they can work their way back off.

 

I did the Carb cleaner trick around the intake manifold and the truck smoothed out and you could hear the fluid being sucked in.

Any recommendations or tricks for getting the gaskets and intake put pack on the truck safely, because I am thinking I must have damaged the new gaskets trying to orient the intake while putting it on. Threading the EVAP hose under the fuel rail and such.

There appeared to be leaks on both sides in multiple places, so I am guessing another set of gaskets are in order as well.

What is the best way to guage the torque since my torque wrench is not "small enough" and only goes down to 10 ft/lbs and the spec calls for tightening to around 3.7 (44 in/lb) and then to 7.4 (89 in/lb) in sequence.

So any tips and tricks would be appreciated.

 

The EVAP line should have a disconnect back by the head so you dont have to thread it through. As for torquing the bolts. Snug them up by hand and then you can torque them to 10. If you pull one out, you'll see that it is sleeved so the gaskets can't be crushed.