Running rich

[samson]

Need some help with my 2005 ford GT. It’s a Hennessey GT1000 twin turbo with a Motec ecu.

Car ran fine in April “last time I drove it” and now it’s running very rich with fumes out the driver side exhaust, passenger side is clean. It will run you out of the garage with the fuel fumes. It’s also very rough idle and not responsive good to the pedal. I changed the plugs and o2 sensors near the turbos and no luck. Looking for some advice

 

[twobjshelbys]

Did you check the ignition packs???

 

[samson]

I have not check them. How do I test them? Car was on a lift for 4 months straight so I am hoping no rodent damage. Had that once on a tractor I left in grass

 

[twobjshelbys]

Don't know how to test but I'd start by pulling each one and repeat but you said you replaced plugs...

 

[nota4re]

Even with your Motec, your car after a brief warm-up mode should enter into closed-loop mode. In closed-loop mode the car will pulse the fuel injectors and immediately get feedback from the O2 sensor that A/F's are right at 14.7:1. If A/F's are rich, it will shorten the pulse and if they are lean, it will lengthen the pulse. Mind you, this is done several times a second and the ECU will keep the car right at 14.7:1. In the event that it can't, a check engine light is triggered with the appropriate error code, e.g. "Bank 1 too lean". V6, V8, V12's will all have a dedicated O2 sensor per bank (side).

By your description, it sounds like maybe one bank is falling into closed-loop and the other is not. When not in closed-loop, the car is in open-loop and the engine is running the fuel injection based on internal tables which may or may not yield a nice 14.7:1 burn.

You need someone to connect to your Motec and see what is going on. The good news is that modern controllers like the Motec should be VERY good at telling you what's going on.

(It is admittedly a bit curious why a Motec was introduced when I believe that 95%+ of the "street" twin turbos are using the OEM ECU, albeit with vastly altered programming.)

 

[MoTeC Magic]

Fresh fuel I assume? E0%-E10% Gasoline right?

With a MoTeC you will have good data to determine the issue. Remote access to the computer should be considered; this will give you the information needed to quickly diagnose it. It could be ignition related, could be rich misfire, bad fuel not igniting, etc...

 

[samson]

I just tested fire on each ignition pack and it has fire on all 8 cylinders. Replaced the drivers side plugs again because there jet black after 1 minutes of idle or less troubleshooting.

 

[MoTeC Magic]

If it ran fine before and isn't now, logically, something has changed. MoTeC has default value settings for things like temp sensors and map / maf sensors, etc. If it has a sensor at a high default sensor value because of an unplugged sensor or damaged wiring... it would explain the rich condition. Example: a map sensor defaulted and showing a higher boost value. You are idling in vacuum and ECU would be reading calculating off of high boost manifold pressure.

Really need to get live with the ECU to be able to determine further.

 

[samson]

If it ran fine before and isn't now, logically, something has changed. MoTeC has default value settings for things like temp sensors and map / maf sensors, etc. If it has a sensor at a high default sensor value because of an unplugged sensor or damaged wiring... it would explain the rich condition. Example: a map sensor defaulted and showing a higher boost value. You are idling in vacuum and ECU would be reading calculating off of high boost manifold pressure.

Really need to get live with the ECU to be able to determine further.

What do I need to be able to hook it up to a computer and have someone check it out so I don’t throw more parts at it? I have done holley efi remote tunes before

 

[MoTeC Magic]

What do I need to be able to hook it up to a computer and have someone check it out so I don’t throw more parts at it? I have done holley efi remote tunes before

Just need the MoTeC tuning software for the ECU that your car is utilizing, the communication cable for it wheter that is a MoTeC UTC or ethernet cable, and a remote access software.

DM and I'll share what I use for this process. Works pretty well...

Cheers