My documented TBI-to-Vortec 350 conversion!

[jdyates]

Small update. It's running good, or at least good enough for my best friends dad to be doing burnouts in his driveway with it

 

[jdyates]

I think my bogging/surging issue lies with the electronic spark advance. Call me crazy, but it just feels like the motor is sitting at base when i punch it. Timing was set with ESC disconnected, then plugged back in. Also, a few weeks ago, right before the head gasket blew, it threw an ESC Circuit failure code randomly. Can anyone tell me all the components that have an effect on spark advance? Gonna advance tomorrow and see if i can get it running smoother.

 

[jdyates]

Bump, anyone have any ideas about the spark advance?

 

[woody80z28]

Okay, having another problem. She's idling a little weird.
-timing is set at 0 with est unplugged
-MAP is at 34kPa at 650rpm and 1.24v
-coolant is at 200° and rises to 210 before coming back down
-block learn is at 124 (what is that?)
-TPS is at .78v
-closed loop

It stumbles and struggles at anything higher than light throttle or idle. Throwing codes 33 (map voltage high) and 42 (est problem)

Any ideas? It was doing all this before the head gasket blew.

BLM is your long term fuel trim. The o2 is reading slightly rich so the computer is pulling a little bit of fuel. 128 is spot on, so 124 isn't bad at all.

I think my bogging/surging issue lies with the electronic spark advance. Call me crazy, but it just feels like the motor is sitting at base when i punch it. Timing was set with ESC disconnected, then plugged back in. Also, a few weeks ago, right before the head gasket blew, it threw an ESC Circuit failure code randomly. Can anyone tell me all the components that have an effect on spark advance? Gonna advance tomorrow and see if i can get it running smoother.

Do you have a new spark table in it yet? The stock TBI calibration sucks with the Vortecs...it needs more advance. A B-body LT1 spark table would be a good place to start. It will also need a lot more Acceleration Enrichment than stock. That ESC circuit failure could be as simple as a wiring problem...I have seen that before with a stretched wire. Check it all out good.

 

[jdyates]

BLM is your long term fuel trim. The o2 is reading slightly rich so the computer is pulling a little bit of fuel. 128 is spot on, so 124 isn't bad at all.



Do you have a new spark table in it yet? The stock TBI calibration sucks with the Vortecs...it needs more advance. A B-body LT1 spark table would be a good place to start. It will also need a lot more Acceleration Enrichment than stock. That ESC circuit failure could be as simple as a wiring problem...I have seen that before with a stretched wire. Check it all out good.

I see what youre saying. It was having the same problem bedore the head swap. If i had to describe it, id say it feels like it's sitting at 0* instead of auto-advancing as i accelerate. I had the timing set at 4* advanced and that helped but it still did it sometimes. Although I cant tell if its short on fuel or spark. Probably both.

 

[94Sierra4x4]

I see what youre saying. It was having the same problem bedore the head swap. If i had to describe it, id say it feels like it's sitting at 0* instead of auto-advancing as i accelerate. I had the timing set at 4* advanced and that helped but it still did it sometimes. Although I cant tell if its short on fuel or spark. Probably both.

Grab a plug with your teeth and crank it over

 

[jdyates]

Grab a plug with your teeth and crank it over

Huh?!

 

[jdyates]

Quick update, noticed today that it only bogs when it's not warmed up. In open loop, or closed, whichever is first, it runs incredible! But as soon as it starts taking data from all the sensors it runs bad.

 

[94Sierra4x4]

Quick update, noticed today that it only bogs when it's not warmed up. In open loop, or closed, whichever is first, it runs incredible! But as soon as it starts taking data from all the sensors it runs bad.

Possibly try a cts? Although I recall reading it would throw a code.. not 100% on that though for sure..
Hopefully you get the kinks worked out.

Oh and grab a plug with your teeth and crank it over... you'll know if theres spark. lol. That's what I was getting at

 

[jdyates]

Possibly try a cts? Although I recall reading it would throw a code.. not 100% on that though for sure..
Hopefully you get the kinks worked out.

Oh and grab a plug with your teeth and crank it over... you'll know if theres spark. lol. That's what I was getting at

Haha yeah I got the joke a few days late. As far as the CTS, it and everything else is brand new, EXCEPT the MAP sensor, and if I remember right, it was throwing readings that didn't make sense. I'm gonna see if I can snag one and a ground strap from the junkyard when I get back in town on Tuesday.