Go EFI-4 (600hp) Computer Issues?
Hello everyone. I'll try to keep this brief, but I seem to be having a few issues with my Fitech unit.
I just got my new engine fired up last week, and it seemed to be running great for a few days. Friday night, on my way home from work, I had a small plastic clip fail (foolishly re-used the clips from my previous motor) which allowed one of my spark plug wires to drop onto the header and melt through, shorting out the plug wire (the same side that the O2 sensor is installed in). Initially I didn't notice a whole lot because I was cruising at highway speed and the wire was likely moving around giving it an intermittent condition, but upon slowing down I could tell there was a dead miss so I pulled into the nearest parking lot and shut it off to inspect (5-10 minutes run time at most).
After finding the problem I went ahead and replaced all of my plug wires, bought some proper clips to hold them in place and verified my ignition coil was still good and double checked the timing. I also changed the oil as there was definitely some fuel in it, replaced all the plugs (carbon fouled on all 8), put a bit of oil in each cylinder due to minor cylinder wash. After re-assembling everything and firing it up there are 3 problems which seem to be persisting:
- Extremely rich AFR. On start-up it's at 14.5, but it quickly drops to about 10.4 - 10.7 and just stays there, even after reaching operating temp (AFR trim is still at 0%, black smoke out the tail pipes).
- IAC steps are stuck at 148, and she idles a good 200 rpm lower than I have it set to. Adjusting the idle screw will bring it up above the set idle, but the IAC still stays open at 148.
- Electronic fan control is no longer working (the fans still runs if I jump the relay). Strangely the CTS is still reading in sync with the gauge on the dash.
This is a 383 SBC with MSD pro-billet dizzy and Blaster 2 ignition coil (vacuum/centrifugal advance, I am not using the Fitech for timing control). Is it possible my Fitech unit is FUBAR'd from a voltage spike, or am I missing something here?
Any fault codes?
Varify your initial settings are still correct.
P0335 - RPM noise
Verify
All of my initial settings were still present, although I did to a relearn and reset them all. Fault code still appears after being cleared.
Yep, very common. There is a pinned post about this. You need to shield your distributor wire for the Fitech.
Tried to copy link. Didn't work. In wiring requirements section. Shielding blue wire.
I found it, will give it a shot tomorrow. Thanks for your help.
Finished shielding the tach wire the other day. P0335 is no longer present, but my 3 issues are still persisting (extremely rich, IAC reading open, no fan control). Twice now I have seen a string of 7-8 codes come up all at once, but it's intermittent, codes ranging from MainRelay to Injectors 1-4 and a few others I can't remember at the moment.
Is there any way to verify this is a computer issue? I've been through all the mechanical now, and the engine definitely wants to run aside from the excess fuel. If I hit the end of the rope I guess I'll revert back to a carb...