Fitech Tach wire connection Q

[Jp76]

UPDATE - wrapped everything in foil, still getting 36 code. Also, took the vac hose off of the PCV and plugged it with a bolt - still rough idle, cant control the IAC steps. seems to do ok until it runs for a bit. I am at a loss - no clue what to do at this point, and left 2 messages with Fitech early in the week along with 2 emails. Nothing back. after attempting to dial in the IAC steps, if I walk away and close up shop for the night, the garage stinks like a fresh open gas can...badly. I assume this is because I am trying to dial in the IAC and the throttle might be open in the TB.

Should I also be playing with the rear passenger side screw maybe?

 

[Jp76]

UPDATE - wrapped everything in foil, still getting 36 code. Also, took the vac hose off of the PCV and plugged it with a bolt - still rough idle, cant control the IAC steps. seems to do ok until it runs for a bit. I am at a loss - no clue what to do at this point, and left 2 messages with Fitech early in the week along with 2 emails. Nothing back. after attempting to dial in the IAC steps, if I walk away and close up shop for the night, the garage stinks like a fresh open gas can...badly. I assume this is because I am trying to dial in the IAC and the throttle might be open in the TB.

Should I also be playing with the rear passenger side screw maybe?

One more thing - I noticed in the logs that it goes from "idle" to "crank" when it almost dies. I have the logs if anyone wants to take a gander.

 

[Bronco1294]

Hey all! Anybody ever get this sorted? I’m dying here. Mines a daily and the wife is getting pretty pissed having to cart me around. Mine was running fine. I noticed the iac steps were off while I was doing some tuning. Now it won’t run at all. 12 volts at the coil, grounded to the battery. 105 and 36 codes at crank. I’ve coil wrapped it, etc. I’m at a loss!!!

 

[73azbronco]

Your fitech is crap, send it back for a new one, demand it, google review, BBB complaint, etc.

 

[John Marinan]

If you have an MSD analog box, I'd be looking at that first. They can cause all kinds of intermittent electrical issues, many of which are heat related. I have Fitechs on two vehicles. On one I removed all of the MSD stuff, it now runs perfectly. It used start breaking up at 3,200 RPM. The other I replaced the MSD box with the electronic unit. It now runs great and doesn't fail to start 20% of time like it used to.

 

[Eoth]

I know everyone is concentrating on electrical noise, but I really think if it was then the engine would run poorly all the time (not just when it gets warm). I think its an air issue...
Either a vacuum leak or an exhaust leak giving the O2 sensor bad data.

 

[DirtDonk]

A good possibility. But there is still the transition from closed-loop to open-loop when warmed up that might be at work here.
It could still indicate a vacuum leak or something of course, but it also might just be when any electronic noise could cause the most trouble.

Jp76 has done some things regarding noise, but I have not re-read the old posts yet to find out what all was done.
In Bronco1294's case though, not sure what all has been checked yet.

You done any fiddling or testing yet 1294?

Paul