Just finished putting in a Ford Performance Racing crate motor in my sons '92 LX. We put in the 345 HP 302 with the GT40 aluminum heads and the "B" cam. BBK shorty equal length headers with H-pipe and 40 series Flowmasters. 70 mm BBK TB and spacer with Trick Flow Street Heat intake and 76 MM C&L mass air meter. After installation we took it to a local tuner who is supposed to be one of the best. Picked up the car and it does run great.

However, my questions are, 1) He told me that my EGR and O2 senors are disconnected and that it is in a "CLOSED LOOP"? Whats does this mean? 2) Does this mean that my efi is not running as it is designed? That it is not adjusting to the atmospheric conditions and is just in a set tune, similiar to a carborated engine, that the computer is not making all the adjustments? If that is so, does that mean that it will always be set to the conditions of the day it was tuned? 3) How will it run in the Fall/Winter/Spring and is it not the preferred set-up? I do not know anything about EFI and this left me wondering. The tuner said "Trust me, I have been doing this for 15 years", but I still have questions. Can some of you guys help"? The car does run outstanding right now, but what when the weather changes? Also, at cold start up, the engine surges about three times from 1000 rpm to about 1300-1400 rpm then stays at idle. Is that normal?

BTW, car made 286 HP at the rear wheels and 331 TQ.

Any answers to the questions would be appreciated. Thanks

 

I think it has something to do with WOT information, but not sure.

I think he set your computer for some kind of WOT optimization, but dont hold me to that.

sorry saw he did do dyno tune.

those are really good numbers

 

Where are you computer tuners? How about some help, please. Thanks

 

Some help?.......Please

 

Sounds like he just unplugged your emissions. Same thing I did on mine. Do you guys have mandatory emission tests in your area? If not, he probably realized you're not going to need that crap and did you a favor.

Nice numbers. I have such a hard time promoting the GT-40 head/Bcam combo here. You'd think the secret co-owner of this site is also the CEO of AFR.

 

Closed loop is when the car coolant warms up to 180* and the car uses the oxygen sensors to help adjust fuel metering. It sounds like the tuner just disabled them from the computer so the car would run in closed loop at all times for better performance. I would ask the tuner personally though.

 

Dath, thanks for the reply. However, you did not answer many of my questions. I am trying to figure out what he has done to the computer and how it is or is not operating as it should be? Any help would be appreciated. I am wondering if he burned a chip and installed it or if he just circumvented the computer? Thanks

 

Also, is this the optimum set-up or not? Could the tuner have done a better job? I paid $540 for this dyno and chip tune. Just wondering if I got my monies worth?

 

Thanks Zach. If he disabled them, why would he tell me that they were disconnected from the system or tune? Can they still work? Thanks

 

He disabled them by disconnecting them. They stop working when disabled. Optimum if you perfer performance over environment. Looks like the tuner did a good job for those numbers with that set-up. Consider some ignition upgrades. He did not circumvent the computer, just disabled one of its operating systems.