TBI to Vortec Head Conversion Tuning Issues....

[kuhio]

Ok folks, as usual I've read multiple post's throughout the web on TBI to Vortec upgrades and tuning issues but I just wanted to see if anyone here could add any suggestions/input to this weekend warrior motorhead.

 Truck Upgrades:
 1987 Chevy 4x4 V10 5.7L 350 TBI, upgraded to Vortec heads, new GMPP TBI Vortec intake manifold, bored .40 over, RV cam, self aligning roller rockers, edelbrock shorty headers with smog, true dual exhaust, 700R4 tranny, rebuilt stock throttle body w/adjustable fuel reg and stock injectors. I eliminated the smog pump and all of the plumbing and capped off the port on the exhaust manifold on the passenger side. Purchased an egr tube for a 96 TBI so I can route the exhaust gases from the exhaust manifold to the new positioned egr on the intake manifold next to the thermostat housing.

 Startup:
 Started right up with hesitation, at first it ran rough at idle and had some backfire & popping when revved and initially couldn't set timing and idle due to vacuum leaks and had sparkplug wires 5&7 reversed, fixed leaks and sparkplug wires then set idle @ around 1500ish rpm's and advanced timing to 10 deg. Sitting at idle then increasing engine rpm's slowly then aggressively is not a problem, no missing no hesitation but when I take her out on the road there is no increased power, can't even spin the tires. At best she's sluggish with a noticeable hesitation when I open her wide up down the road. I found that the sparkplug wire on cyl #6 was burnt and exposed to arcing against the oil pickup tube <need to protect the wires from the headers>!!

 Probable Fix??:
 I will install a new set of sparkplug wires...I have yet to set the fuel pressure on the new adjustable regulator to around 18-20lbs?...I also have two new fuel pumps I have to replace in the fuel tanks for increase fuel flow and adjust the fuel regulator to match the increased hp. Will I need to upgrade the ECM prom to match the new mod's? And btw, the builder spec'd the motor at around 320hp without being dyno'd.

 Sorry for being longwinded but wanted to know if anyone has any input/suggestions/fixes on my issue before I give in and bring it to a mechanic?

 Thanks in advance!!

[Captkaos]

You didn't say what computer you are using or if you are using the stock EPROM.  If you are using the Stock TBI ECM and Prom you need it changed.
Did the builder spec it out to work with a TBI?  Are you running a stock fuel pump?

[kuhio]

@captkaos....yes it still has the stock ecm chip, stock fuel pumps, and stock injectors. I also modified the tbi to an adjustable fuel regulator so I can increase the pressure to around 18-22 psi. I purchased two ac delco fuel pumps (EP-381) in order to suffice the higher fuel rate for the vortec heads. I'm holding off on replacing the injectors unless I absolutely have to. I've been looking at either Jet or TBI Chips for a custom chip to match the current upgrades.

Hopefully this will resolve my issues....thoughts, comments?

Thanks

[Captkaos]

What kind of pressure are you getting from the pumps now.  Most are topped out at 15..  If they are old more like 12...
Until you get all the new stuff programmed into the chip, it wouldn't expect much from it.  Was it built with TBI in mind?

[kuhio]

I'm in the process of installing an inline fuel pressure gauge or fuel fitting where I can periodically check the fuel pressure. And yes, the build was to keep it as a tbi build with vortec heads. Had to purchase and install a GMPP intake manifold for vortec heads.

Thx

[Captkaos]

Was the cam selected with TBI and factory ECM in mind?

[VileZambonie]

Let's see your EGR setup

[kuhio]

Since the new GMPP tbi  intake manifold doesn't have the internal passages for the exhaust gases I had to buy the insulated external egr tube that plumbs from the exh manifold to the egr port on the int manifold. The egr unit is in the front instead of the rear like on the stock int manifold. Since I'm running edelbrock shorty headers I'll need to drill a hole on the drivers side exh manifold and weld a bung in order to connect the egr tube to the int manifold. I'll tackle this later down the road since I'm not in CA and I should pass the vehicle emissions inspection here in TX.

Last but not least I need to swap out both stock fuel pumps (45-55lbhr) in both tanks to the ac delco EP-381 fuel pump (80-155lbhr)...new fuel injectors...order a custom ECM chip...and set the fuel pressure to aroung 18-22psi in order to suffice all of the mods when I upgraded to the vortec heads. Right now, everything is running smooth with the stock setup (fuel pressure, ecm chip, & fuel pump) but hopefully when I'm done with the fuel tuning, I should have the power rating the engine was built for.

<fingers crossed & knock on wood!!>

[mike357]

Go here http://www.dynamicefi.com/
This is a flashable ECM that you do away with the chips. You will have more control over your ECM and it has a learn function that you can let it set itself. The learn will actually create a new .bin file that you flash the ECM with.
You give them the number of your ECM and they will send you one that has been modified. It's about $465. or so once you get everything you need, but it is better than sending off for new chips. In the future you can change something and just re-learn and you're good to go. You can also turn off the EGR circuit completely.

[LeftysRodandCustom]

scrap the tbi and egr, throw on a holley and light em up!