94 C1500 4.3 to L31 350 vortec swap

[jbrenneman13]

Ok heres another thought.Im wondering if one or more of my valves isnt a little to tight causing it to pop through the exhaust?I remember one of my friends had an old chevy that he put a new sbc in and it would do the samething.Come to find out a couple of the valves were just a little to tight.

[EagleMark]

I will try that tomorrow and see what happens.

That was my first thought that I may have put the wrong chip in but checked and it is the one that I got from tbichips.com that is suppose to be programmed for my motor unless he programmed it wrong.

Would it hurt anything to put my V6 chip in and see if it does the same thing?If does then that would mean my TBIchips is programmed for a V6 right?

There's a lot of guys on here good with Memcal issues, jumpers and swaps. I just use the right stuff. They convert a 6 cylinder netres to 8 cylinder netres. The netres chip is under the knock module board in memcal next to chip I'll attach a picture.

Ok heres another thought.Im wondering if one or more of my valves isnt a little to tight causing it to pop through the exhaust?I remember one of my friends had an old chevy that he put a new sbc in and it would do the samething.Come to find out a couple of the valves were just a little to tight.

Always a issue, I thought this was running before the swap? Yes check valves or do a compression test.

[jbrenneman13]

Yes the motor did run before the swap.The last time it ran was nearly 4 years ago.I went through it and replaced all the gaskets before I put it in to freshen everything up.

I will readjust the valves tomorrow and do a compression test on it as well.If my chip I have now looks like the netres on the V6 chip could that be causing my problems?

[jbrenneman13]

Well the CEL is off now.The transmission harness wasnt plugged in all the way.I readjusted the valves today and found that the valves on #3 cylinder were just a little to tight.While idling it doesnt pop through the exhaust anymore.

I called Brian at TBIchips to talk with him about it backfiring through the tbi.He said to set the timing to 0* at idle with the tan wire unplugged.Then to shut it off and plug the wire back up and it should be running 16* @ idle and 33* @ 3300rpms. Does this sound right?I will have to wait until tomorrow to fool with the timing.My timing light bit the dust on me and I suspect that it was bad while I was trying to set the timing yesterday.So I went and picked up a new timing light but its to late to fool with it tonight ( dont wanna make the neighbors mad).

[Fast355]

Well the CEL is off now.The transmission harness wasnt plugged in all the way.I readjusted the valves today and found that the valves on #3 cylinder were just a little to tight.While idling it doesnt pop through the exhaust anymore.

I called Brian at TBIchips to talk with him about it backfiring through the tbi.He said to set the timing to 0* at idle with the tan wire unplugged.Then to shut it off and plug the wire back up and it should be running 16* @ idle and 33* @ 3300rpms. Does this sound right?I will have to wait until tomorrow to fool with the timing.My timing light bit the dust on me and I suspect that it was bad while I was trying to set the timing yesterday.So I went and picked up a new timing light but its to late to fool with it tonight ( dont wanna make the neighbors mad).

16* at idle sounds way low at idle....My stock vortec express tune idled at 22-24* of timing. No load 3,300 rpm is in the 38* range.

[EagleMark]

We've had a lot of problems show up here from TBIchips.com with same issues. 16* at idle seems to be the only thing he knows. Also in another thread the guy was so desperate to make his engine run he kept adding timing till his base distributor was at 11 degrees and it ran great. When he confronted the TBIchips.com his answer was "I've always had good luck with TBI timing tables in Vortec head engines!"

Here's how he gets the fueling dialed in...
http://www.gearhead-efi.com/Fuel-Inj...LMs-every-time!

[Fast355]

We've had a lot of problems show up here from TBIchips.com with same issues. 16* at idle seems to be the only thing he knows. Also in another thread the guy was so desperate to make his engine run he kept adding timing till his base distributor was at 11 degrees and it ran great. When he confronted the TBIchips.com his answer was "I've always had good luck with TBI timing tables in Vortec head engines!"

Here's how he gets the fueling dialed in...
http://www.gearhead-efi.com/Fuel-Inj...LMs-every-time!

If you think his work is bad now, you should have seen it 7-8 years ago....LOL...He couldn't even get a TBI to perform on a single plane intake in person.

A stock TBI chip runs a Vortec pretty well at 8-10* advance with about 22-24 psi of fuel pressure and a vafpr.