Bye-Bye F.I.

**04SilveradoMykk** · 02-06-2009, 08:27 AM

I decided after months of daily driving my Frankenstein of a Silverado it was time to change few things up.

Background: My 2004 Silverado

It was a six cylinder but now has a .040" over 350, LT4 Hotcam, 10.2-1 compression that I built last year.

**04SilveradoMykk** · 02-06-2009, 08:28 AM

I drove it for 3 months with PCM problems, fuel injection issues, drinking 6-8MPG and not delivering the power the engine is capable of. I finally had enough and just gutted the fuel injection.

**04sierracrewcab** · 02-06-2009, 08:29 AM

That sure is a slick truck!

**04SilveradoMykk** · 02-06-2009, 08:29 AM

Instead of a PCM controlled fuel injection I decided to go old school, I mean the only thing weirder than having an old SBC in a newer truck is to have a carbed SBC in a newer truck. right?

Professional Products 52028 for vortec heads, split dual plane, air-gap design

Summit billet aluminum ball bearing distributor with a magnetic trigger.

Edelbrock 1407 750cfm carb, jet & rods for 4% lean for my altitude. Modified with a TPS so the PCM can still control the 4l60e trans. Mallory 4309 fuel pressure regulator, phenolic 4 hole carb spacer to help throttle response.

**04SilveradoMykk** · 02-06-2009, 08:29 AM

**04SilveradoMykk** · 02-06-2009, 08:30 AM

The Carb is mounted backwards on the manifold, this is to allow the trucks OE throttle cable to bolt up as well as the TPS & fuel lines will be on the correct side. Mounted the coil directly on the valve cover with a VC hold down bolt.

Made a new upper radiator hose, shortened the taylor wires and put her back together

**04SilveradoMykk** · 02-06-2009, 08:30 AM

As long as the PCM still has a TPS, VSS & CKPS signal inputs it can control the 4L60E and gauge cluster including the tach. ( although mine still reads a six cylinder)

Here is a short video of the fist fire-up after the carb swap, without any ignition timing or carb adjustments.

http://vimeo.com/3075250

However there is just one problem, despite having the fuel pressure regulator trying to regulate 60PSI down to 6PSI the fuel return line is too small to handle to excess pressure and it's getting backed up. So much so it's allowing the pressure to get to the needle & seat of the carb and it's over powering them causing a flood out.

So on to the 2nd half of the project. Dropping the tank to pull out the in-tank fuel pump and install a much lower PSI electric pump onto the frame.

**04SilveradoMykk** · 02-06-2009, 08:31 AM

A carter electric fuel pump, 72GPH@ 5.75PSI

As of yesterday she's back on the ground and driving quite nicely. So much more, more everything!

So much torque, so much better acceleration, better exhaust tone, better "camed" lumpy idle, And it's drinking less gas!

My next project will be a locker in the rear end. That one tire just can't handle it. And I might swap out that cheap torque converter out to a better quality stall unit, something with a much better stall torque ratio instead of my current "light switch" converter that just seems way too loose.

Cheers ~Mykk