Hey guys, I have a 89' K5 with a 350 TBI. Been surfing the site for a while, but I have a question that I can't find an answer to. I bought a Crane HI6s kit for the truck and it runs like crap with the box hooked up. Hesitates, misfires, just sucks. Runs fine without it. I have a new MSD cap and rotor and new Taylor 8MM spiro wires. Stock plugs gapped at stock just like Crane recommends. This is the second box, so its not a Crane problem. If you arent familiar with the Crane system, its plug and go, no wiring splices, all weather pack connectors. I know its installed right, I know its well grounded, and the truck runs fine without. Any ideas or similar experiences?
Thanks
AW

 

What dose Crane have to say about it? Dose it have a rev limiter built into the system. Have you tried playing with the timing? Hope it's something simple.

Steve

 

I had a similar problem with the HI-6S. Mine wasn't as bad as your problem, though. When it was hooked up, it was running VERY rich and didn't have that crisp thottle response.

I contact Crane and they said they have seen cases (not many) where the ECM receives a weak signal from the box which causes the fuel to be enhanced. (I can't remember all the exact specifics, but it all made sense at the time). I replaced the ignition module, ESC (knock) module and even the pickup coil in the dist. Nothing worked.

I then called Crane back and they said to try this: While the HI-6S is hooked up, set the two pot switches to 0 (this will disable the functions of the HI-6s -a bypass, if you will). If the engine then runs better, you need to upgrade to the HI-6 (note, not the HI-6S). The HI-6 is a CD type box rather then the analog that the HI-6S is. Crane said they would replace the HI-6S for the HI-6 free of charge! (Here's were you can make out since the HI-6 is a BETTER unit and cost $200 whereas the HI-6 is only $135).

If you do not see a change in the engine (with the pot switches set to 0), then there is a problem with the unit itself.

I sent mine back to Crane and within a week, I had a brand new, HI-6 unit complete in a box!! (Note: The HI-6 is about 25% larger than the HI-6S).

I hooked it up and it resolved the low, rough, rich idle and lack of thottle response.

Hope this helps and let us know the outcome!

Later,
Mike

 

Crane has no idea. They supposedly referred my case to Engineering, but they never bothered to call me. Timing is set at 0 degrees. Rev limiter is set at 5500.
AW