Ok so, i have an AUTO ecu currently with a boomslang FIC harness (does not have the resistor mod). I had an FIC in there and car was running for over a year with it but the tune was off a little - would hit weird rich spot around 3k cruising in any gear. (below 10 afr). so i go to get tuned and this FIC doesnt respond to any tuning so we figure it has some issues. Get a new FIC in the car, start tuning, runs great except that i need a resistor mod because hitting the 5k area WOT hiccup. so i start driving home, all the sudden car is dying at stops, and the throttle body is opening and closing along with rpm's going all over after the car is off. Even after taking key out, throttle body is going. Sometimes the car will only hunt at stops after leaving it off for a bit but after turning it off and then on again and driving, at every stop it shuts off.

Do i need the relay for auto ecu mod?

Is the resistor mod all i need?

Maybe the harness is for a different year than my motor?

What could be causing this.

Also sometimes my RPM's will move by themselves with key in ON position & i hear whining after turn car off from bay. (only on the replacement FIC)

 

*This happened after i stopped to fill my tank after the tune about 2 miles down the road. Filled up, trouble starting and then stalled at first stop.

*This morning i took it for its first drive and it was ok, no stalling but it was hunting. After turning it off and then back on, it stalled at every stop.

 

get a manual ecu.

 

i would just get a junkyard manual ecu and not worry about the battery issue. the can be found cheap.

 

ok but ive been reading in the auto ecu post and it hasnt created this issue yet and ive been on auto ecu for 4 years on boost no problems.

 

Question is why would the old FIC not be affected by the auto ecu but this one is?

Also my RPM's are moving around by themselves when key is in ON position & i hear the throttle body moving after the car is off aswell.

 

mine used to do that too soflo (the whine) i have no idea why it went away but it did.

also maybe they changed something about the fiC and that is why this one is affected. you can pick up ECU's cheap. i would most definitely grab a manual ECU.

as for the rich spot it sounds like the auto ecu is adding fuel at that point.

dumb question but you did calibrate the new FiC after you installed it right?

 

bump

 

Syldrin - the rich spot was only with the older FIC though, we had no issues with this more recent FIC... car was running spot on, until i got to a gas station, filled up and then started driving again.

 

Will a manual ecu still work with my auto harness?

 

Yes

 

Any write up on swapping to a Manual ECU? i had read we have to bypass something?

 

Something with the park switch Nd then Ofcourse you will need to jump the Connector on obd2 to mate the Ecu to the ignition, call ptunjng or dezod

 

i just realized i have an 08 motor with an 06 auto harness... and god knows what year my FIC pnp is for...

 

well that might be a problem...

 

even then why would the car run flawlessly while getting tuned

 

start looking into getting an 08 ecu and 08 manual harness as well as an 08 pnp harness, or keep on running into issues. either way.

 

what about everyone that has just dropped in countless motors... i feel like an 06 MT ecu would work with an 08 motor...

 

You can run any year Ecu on any year motor so long as the engine harness matches, the only difference in the motors really is the oil squirrels and the compression, I've ran countess 2jz harnesses on 1jz engine and vice versa same as 2az engines I'm on a 06 Camry engine with a 08 harness n Ecu

 

Who tuned the car?

Sidekick 4G