Sniper 2 EFI

The EFI conversion is complete- and it's amazing! I replaced the Edelbrock carb and HEI distributor with the Holley Sniper 2 and Hyperspark distributor and coil. I also went with Holley's returnless in-tank fuel pump. The entire installation was fairly simple but I wouldn't call it 'easy'.

The fuel pump install was fairly simple. Basically just take the old sender out and put the new Holley unit in. I had originally installed a 3/8" fuel system so I was able to keep most of that. Oddly, there isn't much documentation on how exactly you're supposed to connect the returnless fuel line to the Sniper 2 unit. After digging around a bit it's simply a matter of only connecting to one of the fuel inlets (either one) and blocking off the other. I had assumed that's all there was to it but it wasn't written anywhere.

Since I had an HEI distributor before I needed to find a place for the new coil and ignition box. I went with a spot on the firewall on the passenger side.

The wiring is very straightforward and yes, you can connect everything in about 5 minutes. However.... there's a fair bit of wiring and wiring harness and trying to find the best way to route everything and tidy it up took a bit of work. I opted not to go for the PMD (Power Management Distribution?) since it really didn't seem to lessen the amount of wiring I had to do, especially since I don't have any electric fans.

The car started right up on the first try. Everything exactly by the book. I followed the directions on letting it idle, going through the gears, etc., and then taking it out for a spin. Everything worked perfect... until I checked the timing. Somehow the unit was working perfectly yet it was firing the #1 cylinder at 5 degrees post TDC instead of 15 degree before TDC. I know the Hyperspark does the timing management and can do some voodoo but I don't know how it can make a "virtual TDC" since TDC is mechanical.

At any rate, I set about trying to fix it and it was pretty straightforward - set the static timing in the Sniper handheld to 15 degrees and then rotate the Hyperspark distributor until I got 15 degrees on the timing balancer. Presto - they now agreed and the Sniper/Hyperspark immediately automatically adjusted to the new timing. However, now the car had trouble idling lower than 900 or so and I was shooting for 750. I kept messing with the primaries but I couldn't get it any lower. It turns out I need to tweak the secondaries and then it easily got to 750 and idled perfectly.

The second and third drives went great until the very end when I was stopped at an intersection and the engine shut off. My worst fear with switching to EFI. I got some help pushing the car to an adjacent parking lot and went to work debugging it. The problem turned out to be the 12V power line going to the Hyperspark. The pin had pushed out the back of the connector when it plugged in. Fairly easy fix but a little scary!

I did a much longer 70 mile drive today including my first time on the highway. Everything worked flawlessly and the throttle response is really, really nice - especially on the highway.