RFmaster

Fired up Carb to TBI conversion on my '75 C20 for the first time on Sunday morning. Short video on youtube.

http://www.youtube.com/watch?v=sfxuOOliRdg

Wow, a lot more throttle response, much smoother idle, etc etc.

Still plenty of work ahead:
In cab wiring harness (you saw that mess didn't you??)
P/N switch mod
TCC mod
TV cable check
Air cleaner assembly yet to be determined

But 8 month of hard work finely paid off - it fired on the first try thanks to TGO for all the help and support.

//RF
__________________
"The Beast"

1975 Chevrolet C20 longbed
350/700R4! with 3inch body lift
Dual Flowmasters Super 40's!
TBI retrofit completed (2007-07-28)

beardb

are you running a stock 350 chip/bin, or a custom?

RFmaster

beardb

During initial fire-up I used 7747 with ASDU broadcast code. I have not had a chance to do perform any data logging due to (to put it mildly) unfinished in cab harness. I have not driven my truck yet, as I still have to modify P/N switch, connect TCC, install auxiliary fuse panel to make installation less than a science experiment!
My engine is basically stock 350 (8.5:1) with a mild RV cam (at least that's what previous PO told me). I'll try to data log this coming weekend while parked - not much help there. I hope this helps.

I do have burn capability and Romulator for real time PROM modifications. But first things first.

//RF

beardb

I hope you have better luck than me. I am using the same broadcast code and way too lean. I would appreciate an update once you have logged some data.

anesthes

iTrader: (12)

Doing the same thing on my '84, but its a Th350 so no TCC.

Did you wire up the VSS and get that working properly?

I haven't started the wiring yet. I have a harness and suck from an '87 I stripped, I figure I'll go to town on it soon. I need a schematic from an '84 truck so I know which wires are the power, vss, and so on so I can splice that stuff in.

-- Joe

RFmaster

anesthes

If you have complete harness of '87 it should be used as a whole.
I do not know '84 truck details - is it CCC Q-Jet?? If it is you can use existing dizzy - just re-do 4-pin connector between dizzy and harness.
CCC also used the similarly spec-ed CTS
In my case I am using VSS from JTR - it is a small unit and bolts up right to the transmission. I have not finished verifying VSS at this time. You'll need 2k pulse unit for 7747 ECM.
Other than that I would use a separate circuit relay (30AMP) - ignition on enabled and several in line fuses to provide power to injectors, ECM-IGN, and heated O2. Fuel pump relay circuit must be installed separately since ECM will controll it.

//RF

anesthes

iTrader: (12)

Well I have the small cap dizzy and all that from the '87. I figured I'd run the harness as normal through the firewall, locate ECM power from the CCC ecm. The injector power I can wire direct to battery with an inline fuse, same with the fuel pump relay. Just need the schematic for the in-dash end of the wiring.

I was told the speedo unit in the dash on the CCC setups has a VSS output that could wire into the ecm ?

-- Joe

RFmaster

Looks like you got everything covered. VSS is probably is built into dash and signal is delivered via DRAC module?? which has 2k pulse/mile output?

In my case I swapped dizzy gear with melonized gear. My disco era 350 uses a hydraulic lifter cam shaft which does not work very well with dizzy gear designed to work with steel roller cams. I could not find melonized gear for 0.428 diameter shaft used by a small hat dizzy.

If you are doing direct transplant ('87 engine into '84) then disregard my comment above.

What are you doing for a fuel pump??? '87 used in tank FP. I use Carter in-line CRT-P5001 3/8" I/O - use at least 5/16 fuel return line. Do not use 1/4 vapor return for fuel return!

//RF

anesthes

iTrader: (12)

Well. The L05 had a small dizzy and flat tappet hydraulic cam. So there is no problem there. I'm not doing a direct transplant, I just am using a lot of stuff off the '87 to do the swap. Motor is a 350 block, thats at the machine shop right now gettign machined up. Hyper pistons, 64cc heads, and edelbrock 2102 cam.

I grabbed the whole tank off the '87 and it's going in the '84.

The '84 has a 5/16" return line as well as a 1/4" vapor line. So that part of it is not too bad, and at 14 or so PSI hose clamps shouldn't be a problem either.

As far as the VSS, i'm taking what I was told on the fullsizechevy boards, that the drac output will work. But I'm not 100% positive. If the pulse is different I can mod it in the chip.

Once I get the motor back from the machine ship, I'll assemble it and start the wiring process. I'll be sure to post some pix.

-- Joe