Hi,

I'm new here, and not an F-Body owner...but I do own a 'vette. It's Chevy though

Anyway, I have a Lingenfelter 383 that used to utilize the factory computer. After having it re-done a few times due to too much timing and detonation...I decided to have a Gen VII installed by a shop I used on previous cars.

It's quite confusing when there are two map sensors on this combination. This was the first vette/ n/a car they'd done. Now what's strange, is I was told the first map sensor was for the tcc/lock up the stock computer is still doing and controlling gauges etc. The second map sensor is solely for the DFI to control the engine.

I have a good friend trying to help me tune the car seeing the shop owners son is VERY busy.

We discovered tonight, there's a specific table that is black and white covering torque convertor control. So, what is up with the double map sensor thing?

also....it never goes to closed loop. My LPE chip(prom) did the exact same thing. When it was tweaked to take some timing out(detonation again, 11:1 compression and hot weather don't seem to get along too well(26 pound injectors) the wide band o2 went in the exhaust and it was de-tuned.

sorry to ramble a little...If I confused anyone, I'll try to make myself more clear.

Thanks for any possible feedback,and I have pictures.

Concluding this story, after having the super ram show polished and replacing a collapsed lifter, I swear the biggest mistake was doing this DFI. I dropped off a perfect car(stock computer), and have been chasing my tail with numerous tuning glitches since. I hope I can get it right.

 

Okay....

1.) Lose the map sensor for the stock computer, and just use the DFI to control the TCC lock up. Sounds like the shop didn't even know that the DFI could control it (WTF?).

2.) Since your car is n/a, you can use the fuel table predictor in the DFI software to generate a base fuel map that will safely start and run the car.

3.) Check your Fuel->Transient->Closed Loop ECT Threshold and Closed Loop Delay vs. ECT tables. If it is enabled through the DFI software, closed loop will control will activate according to those parameters.

4.) What type of O2 sensor do you have? Wideband or HEGO?

5.) If you've never done tuning, the DFI unit can be a little tough to learn on. You may be better off talking to a dealer about getting it tuned. I can recommend one in your area if this is the case.

6.) Ask more questions if you need to.

 

I am a bit frustrated with this DFI system. It hasn't performed nearly as stable or smooth as the stock system. I already have a backup plan to yank it in case we can't get it to the way I want it.

How would I lose the first map sensor? Trace the wires to where it is attached to,and plug the vacuum lines.? Everyone that sees it wonders why it has two map sensors.

All the controls for the TCC are in the DFI's software.

Also, when the fans turn on, the idle goes lower, shouldn't it go higher? And forget using the air conditioning, it makes it stall all the time. I think there's a setting for that also..but we're waiting on the power key or whatever to tune it(Security device).

Thanks again.

 

[COLOR=red]Be careful making changes in real time with the pwr key! one wrong keystroke and your in trouble. THINK all changes thru before sending them to the computer!

 

Thanks for the info, it's going to be carefully done,and additional thanks for the warning on the power key.

The shop owner warned me, one wrong move and it won't run. I guess that is what He meant.

I'll let you know how it does......

"Keeping fingers crossed'

 

Map Sensor:

Really, if it were me, I'd be asking the shop why they went and left 2 map sensors in the car. Explain to them that there was no need for this, and make them fix it... Otherwise, as said above, just plug the vacuum line and remove the sensor.


Air Conditioning Compensation:

If you are not using the 2-Step rev limiter, you can switch that input to function as an AC feedforward request input on one of the configuration screens. This allows you to program the amount that the IAC motor is bumped when the AC comes on to allow the added load to be handled seemlessly.


Fan Idle Compensation:

You have some trim tables for IAC position mins and maxes vs. ECT. Since you know what ECT will cause your fan to come on, you can set the limits as needed to keep the idle stable. Use these along with the target idle speed table. Only play around with the values on the Idle configuration screen if you really think you have to.


If you are still waiting for your security key, you can always play around with the software offline. There is no key required for that, and you can create a full calibration file to send to your ECM later when you have the security key.

 

This is one hellova forum!

Thanks for the assistance. I'll let you know how it works out.

Jay