Olds 403 FI Conversion 8/27/00

I finally took the leap this weekend, and took the FI setup off the testbed 403 motor and slapped it on the '71 Cutlass .  This is the culmination of probably about 5 years of procrastination, parts collecting, and information slurping from the DIY-EFI and GMECM lists.     For a timeframe, I think I have one of the first posts on either the DIY-EFI or GMECM list, I don't remember which.   This is just a brief (yeah, right!) detailing of the install and some related facts.   This is made from about 99% stock GM components, most found in scrap yards, some found in shop trash mainly 'cause I'm a cheap bastard.  Here is a brief rundown of the important details:

Olds motor with stock carb and 80 lbs cast iron intake.  Jeeze, this thing will handle better just 'cause the new intake weighs about 40 lbs less!

This is the new intake on the test motor, sans throttle body.

The TB gasket here is from a '75 Seville; used a bigger throttle body, but the intake was cast iron.  I enlarged the holes on the Bridgeport (err.... drill press).  Stock on right, modified on left.

Woo-Hoo!  New intake on the motor!

TB on motor, harness just laid on fender and hooded up to verify that it all fits.

Detail shot of fuel lines coming up from frame, and fuel filter.  This is the Aeroquip "sockless" push-on hose.  Cut down NAPA fuel line repair kit to adapt 3/8" inverted flair lines to a Saginaw o-ring so I could use a standard GF481 filter.

Detail shot of throttle linkage.  Amazingly, the stock '77 Seville throttle bracket fit with a spacer.  Note how throttle cable just clears distributor cap.  BTW, bolts in spacer came out of the Quadrabog from the old motor.  These were the long ones in back behind the secondaries.    Also you can see the TBI throttle body with injectors removed and hole covered with some aluminum sheet scrap.    I moved the TV cable from the trans to work off the gas pedal, no room to hook to TB.

Ready for harness to be installed.

Harness on floor.  List members will remember asking about where to cut a hole for the harness.  Well, should have used a '727 underhood - hindsight is 20/20.   I decided to put all the extra harness under the dash, since I've got plenty of room - no A/C!    Easier to pass ~20 wires thru the firewall than a full harness and have all that bulk under the hood.

Harness installed - just need to add plug wires and it's ready to run!  The hole in the firewall is actually the stock hole that the heater fan motor wire ran thru - right above the heater hoses.  it was about 1" in diameter, I enlarged it to about 1.5 to accomodate the largest connector (EST from distributor).  Still looks stock after I added a grommet, and it's nice and far from exhaust or excessive heat.    The stock alternator bracket doesn't fit (hits the #2 injector, and no bolt hole for it anyway), so a turnbuckle to a bar coming up off the front of the block does the trick just fine....

Oh, here's the car it's in:

Startup and Run:

I ran the fuel pump for about 20 minutes to check for leaks.   One small leak at a fitting I didn't completely tighten.

Popped in the ECM fuse, installed a AUJP bin with VATS disabled and turned the key.  Wrrr, Wirr, Voom!  Fired right up to a crappy idle.    Set timing to 8deg, idles better.   Warmed up, no leaks, no smoke.

Borrowed scan tool wouldn't link up... hmm.... ALDL connector came from a '91 Astro van... hmm.... Snap-On MT2500 knows which pin in the ALDL to look for data.  Seems the Astro van and the Camaro have different pins!   After 2 hours to figure this out, I finally got data.

It's now 3am - perfect time for a test drive!  Amazingly it's actually not that bad!  Throttle response is great, but it needs quite a bit of tuning.     Impressive that you can take a total mismatch of GM parts and it will run and drive without setting a code, says a lot about GM engineering.

Really cool to be able change timing and or "jets" just with a few keystrokes and a chip change.

Big thanks to the GMECM and DIY-EFI for all the help and knowlege, and putting up with more than my share of dumb questions.   

-> Bob
-> bob [at] tecmark [dot] com