SATAN

iTrader: (2)

Just got my 1999 Silverado PCM and harness today. spent a while cross referencing my wiring info...

This is a custom install, I want to hook the OEM PCM up and OEM harness up and to a test fire just to make sure everything works and the engine runs. Even if it runs really rough... that's fine.

My question is, I will not be using a MAF when all is said and done after tuning with HP Tuners. However, HP Tuners hasn't shown up yet, and I don't know if the engine will even run without having a MAF hooked up on the OEM programing. So... will it run, even if it rough? On an OEM 300zx, it will run and idle fine, but wont rev past 2,000 rpm's. But I don't know about GM.

Also, OEM O2 sensors... I don't haven any. I do have a single wide band though. I was going to eventually send the narrow band signal that the wide band is capable of putting out, back to the ecu. Will I have to send that signal to all 4 O2 sensor inputs, or just the rears, or just the fronts? The engine will run without O2 sensor hooked up, right? Even if in limp mode, it should still run right?

Again, this will eventually get HP Tuners and all tuned out. This is just a test to make sure everything "sort of works" before I go too far.

Thanks for the help guys.

gregrob

iTrader: (8)

Yes, it will run fine... It will revert to SD mode when it sees no input from the MAF.

You will have rework a lot of the harness to get it to easily fire up on an engine stand... You basically have to turn it into a two wire harness, with all shared power and ground hookups.

That or run the fuse box out of the engine you got the wiring harness from..

flame

iTrader: (13)

Being a truck harness and pcm it will not run without having the VATS turned off. It will start and stall because you will only get one injector pulse. Also on the MAF it can run without it but the intake air temp sensor is built in to the truck MAF so you will need to wire in an external IAT. For O2's you need a sensor in each bank front unless you are going to tune it open loop.

SATAN

iTrader: (2)

Thanks for the help guys.

Ok, HP Tuners just showed up today. I still have yet to even open the box and read instructions, but I am willing to bet, the ECU has to get its power and needs to be up and running before I can turn VATS off using HP Tuners.

As far as the air intake temp sensor, I already have an external GM IAT sensor that I will be using. It is the same one I used on my last build that utilized speed density.

For the O2 sensors, I was just going to send the narrow band signal from the AEM wide band that I have and split it. Then I can run the same voltage signal to the right and left front bank. I think anyways... I don't know if that will work, but I dont see why it wouldn't.

Thanks again guys.

flame

iTrader: (13)

The pcm controls fueling by bank so splitting the signal will not give it the proper information to control the fueling properly.

SATAN

iTrader: (2)

Well, that doesn't work on a single Turbo application. You have one down pipe only. On top of that, you can't put one wide band on each bank before the Turbo because too much pressure will mess with the wide bands readings.

eviltwin_1987

iTrader: (18)

Need narrow bands, one each bank pre turbo for STFT and LTFT to work aka... Closed loop