EFI with HEI what's the deal?

[killahxft_jeep]

I have the 4 Wire HEI unit installed & running great... can I use this with the Howell EFI kit? what mods would I need to do to either the kit or the distributor? will this work or am I stuck with a carb? not planning to do this mod for a while.. it's on the back burner.. also I have true dual exhaust.. will the O2 sensor get an accurate enough reading from one bank of the exhaust to adjust the mix properly???

[tufcj]

If you tell Howell you're using a ECM controlled HEI, they can add the wires to the harness, and add the control to the PROM. I would have done it when I put the Howell EFI on mine, but an aftermarket HEI for AMC wasn't available 6 years ago.

I love the Howell setup, except for a bad O2 sensor, it's been flawless for the 6+ years I've had it. Starts easier, idles smoother, throttle is crisper, and it runs at ANY angle, even upside down (don't ask how I know :shock: ).

Bob
tufcj

[killahxft_jeep]

this is an aftermarket 1 wire HEI unit with mechanical/vaccum advance.. there are no provisions for electronic ignition control..

[tufcj]

Then you just let it work like it does now. I'm running a Mallory Unilite on my CJ with the Howell EFI. Just make sure your distributor is curved correctly for the RPM range you're running in. Not quite as efficient as computer control, but it works fine. If you order a Howell setup without ignition control, the only ignition wire that gets hooked up is a tach lead, which the aftermarket HEI should have.

Bob
tufcj

[killahxft_jeep]

yup it has a tach lead... just splice into that for the howell? how should I power the ECU for the howell EFI? I have the 12 circuit painless harness which has no provisions for a computer..

[tufcj]

There is actually a power lead for the computer in the harness that you get from Howell. They suggest you add an aux fuse block, or maybe you can use an empty slot in the painless fuse box.

I used a 6 slot fuse block I got at the local auto parts store. I mounted it under the dash, and power it from my "aux" battery (dual batteries in the CJ). Ran an 8 gauge wire with a 30 amp self-resetting breaker to power the block, then you insert whatever amperage blade-type fuse in each output slot.

Howell's instructions and wire markings are very clear. I installed mine in about 8 hours, including upgrading the fuel lines from 5/16" feed and 1/4" return to 3/8" and 5/16". This is something they suggest, but not mandatory. Started first turn of the key, needed a little tweaking of the throttle plates to stop the "whoosh" of the IAC, but nothing more than that.

Bob
tufcj