Help vortec head swap engine doesnt run right

[rotarymedia]

Vortec head swap on 1990 tbi using sumit vortec intake and 062 heads with the stock tbi, it just doesn't run right it idles and everything but when you go to drive or rev it will backfire and have no power, keeping your foot steady it will buck untill your speed evens out absolutely gutless. We've tried every degree of timing we reset the dizzy, the valves a adjusted correctly, we thing something with the tbi pls help we need this truck running now

 

[International47]

I'm interested is this, as im about to do something similar.
( heavily ported tbi heads that should flow close to vortecs and either the LT1 or good old rv cam)

What fuel pressure do you have?
fuel pump, fuel pressure spring?
have you deleted the EGR?

And EBL-flash tuning i believe would be the proper way forward.

 

[L31MaxExpress]

It needs more fuel delivery (Vortec pump and more pressure is the cheapest way) and tuning. No other bandaid around it. With the stock 350 injectors it probably needs 18-20 psi fuel pressure, it will need more accelerator pump shot and the whole timing map in the chip needs to be re-worked.

 

[Hipster]

Vortec head swap on 1990 tbi using sumit vortec intake and 062 heads with the stock tbi, it just doesn't run right it idles and everything but when you go to drive or rev it will backfire and have no power, keeping your foot steady it will buck untill your speed evens out absolutely gutless. We've tried every degree of timing we reset the dizzy, the valves a adjusted correctly, we thing something with the tbi pls help we need this truck running now

LOL, smh.

 

[Hipster]

I'm interested is this, as im about to do something similar.
( heavily ported tbi heads that should flow close to vortecs and either the LT1 or good old rv cam)

What fuel pressure do you have?
fuel pump, fuel pressure spring?
have you deleted the EGR?

And EBL-flash tuning i believe would be the proper way forward.

Like L31 tells you......tuning

 

[Hipster]

Vortec head swap on 1990 tbi using sumit vortec intake and 062 heads with the stock tbi, it just doesn't run right it idles and everything but when you go to drive or rev it will backfire and have no power, keeping your foot steady it will buck untill your speed evens out absolutely gutless. We've tried every degree of timing we reset the dizzy, the valves a adjusted correctly, we thing something with the tbi pls help we need this truck running now

Why people think they can bolt together whatever they want in spite of multiple warnings eludes me.

 

[caminonut]

Do you have the temp sensor from your stock intake installed in the summit intake?
It will really run bad if that is not connected or installed.

 

[Hipster]

Do you have the temp sensor from your stock intake installed in the summit intake?
It will really run bad if that is not connected or installed.

That would be a given.

 

[International47]

It needs more fuel delivery (Vortec pump and more pressure is the cheapest way) and tuning. No other bandaid around it. With the stock 350 injectors it probably needs 18-20 psi fuel pressure, it will need more accelerator pump shot and the whole timing map in the chip needs to be re-worked.

L31Max- I know you have done the ported tbi heads a long time ago.

Would the increased fuel pressure ( pump-spring) be enough for the stock tbi computer to make it run ok on ported tbi heads/ vortec heads?

Or would the overall increased fuel , be too rich at idle and not enough at higher rpms? ( as in the stock computer cannot meter the injectors correctly)

Any recommendations for tuning hardware ( EBL-flash, cobraRTB emulator, older flash burning)
this info would also apply to the original poster in this thread.
thanks