Hi Guys,

My build is almost done and I have a few more hurdles to get over, and I was hoping maybe someone here could help me out with a few bits.

Firstly, I stripped the TPI motor harness and relays out completely and have just the power harness in the engine bay, there are no relays in the engine bay at all.

Does the 0411PCM still need relays for MAF?
Is the fuel pump relay in the cabin, the rear, or was it in the engine bay?
(if the latter is the case, how would i wire one in?)

Are there any relays the 0411 setup would need?
At the moment I'll be wiring a relay for the thermo fans and one for A/C

Will the 0411PCM with LS1 OS be able to use the 1997 Firebird LT1 gauges?
Will the fuel tank gauge work?

Do the LT1 Gauge lights for airbag,traction need to be wired if not used to keep the lights off, or can i leave them unconnected?

Are the coil packs powered by the PCM or does it take power from a relay or direct from battery?

 

Are we talking about an LS swap here? Or some other 0411 application?

I have never had an EFI 3rd gen, but I understand the fuel pump relay is in the engine compartment (but, I could be wrong...). Since my LS swap vehicles started out with no in-tank electric pump, I didn't have a fuel pump relay. I used an aftermarket fuse/relay box for one swap, and the donor fuse/relay for the other, both of which had a fuel pump relay. And, I had to run a wire back to the tank in both cases. (I guess there's a 3rd, the '57 Bel Air - I used a Painless fuse/relay box in it.)

I understand the '93-'97 f-body instrument cluster used the same resistance for the fuel level as 3rd gens. '98-'02 changed to a different system, using serial output from the PCM.

The factory uses relays for the switched power to the PCM. Reduces the current load through the ignition switch.

I'm trying to remember about coil power. Pretty sure it's switched 12v. The PCM controls firing them by making and breaking the ground side of the circuit.

 

You should delete maf and just run speed density. Makes it easier

Easier to run the tpi fuel pump relay by the c100 firewall connector. You dont have to, can make it stand alone but its factory wired from pump to firewall and all you need to do is take the one wire from tpi ecm and plug it into the 411 pcm. Simple and easier

 

I thought MAF was eaier to tune and more forgiving for modded engines, or is that a myth?

I don't have a MAFless tune base file to start with, how difficult is it to remove the MAF from the tune using TunerCat OBD2 free version?

The fuel pump is wired to the set of plugs in the cabin, 2 plugs letter A-J & K-P i think, a tan and white wire, if i put 12volts to that it starts the pump, I'm assuming I just need to wire the relay to that and have the PCM attached to the trigger wire of the relay?

 

A good tuner will handle anything. Maf is ok and can compensate somewhat but thats the whole point of tuning anything, to have a good running setup with no issues. Eliminating maf is just one less thing to wire.

It should be a simple disable maf option. I use hptuners tho

 

Mafless doesn't comply with our emissions , however (and in your case i think it may work for you so look into more) i believe because your using a sbc that was carbed originally. You can convert to efi without MAF.

If it was a ls engine or a sbc tpi engine with maf, then you'd be up the creek. Not sure how they can check it tho for engine originality as i'm guessing you could say its a 350sbc carbed.

On my ls1 ecu it runs the MAF directly, with a ref 5v+, ref 0v ground(maf only not body), and signal wire. No relays or such required.
Do the mafless conversions here swap out the MAF for a MAP sensor on this connector/loom section ?

Fuel pump side, you are correct. If you can trigger it running from those connectors, use a relay (as the ls ecu does do) to trigger it. If it had a relay on that connector and you applied 12v to it, unless its the trigger input for it, it wouldn't activate the pump. But you'd hear the relay click if that was the case.