Ok, so I've been having some issues...I just got my Ostrich and am looking to iron things out. The general consensus from what I've seen on fullsizechevy.com forums and other forums is that the less you "lie" to your ecm the better, but this has me stumped...

Setup is in a '72 Cheyenne/20, TH350, 4.11 rears, 350 with a stock cam, stock intake (for now anyway), TBI-->Qjet adapter and a 454 tbi with 350 injectors. I've got a moates G2 and an ostrich in a '7747 ECM. The bin I started with was from a 4.3 truck because it would start the easiest.

Now, here's where the headaches start. BPW is set at 135, and cylinder select is at 6. Truck starts within ~3 seconds of cranking and runs descent...gets horrendous mileage, but its missing a VSS and I know I need to do some more BLM tuning.

Now, when I turn the bpw up/down more than ~3 with it at 6 cyls, the truck won't start. I turn the cylinder select to 8, it won't start, I keep it at 8 and I go up/down, still can't seem to get it to start.

For the time being, I can't afford a heated WB02 sensor (tho in a couple weeks I'll probably buy one) so I don't know exactly how much fuel its dumping in. I guess my question is, does anyone have any advice for tuning starting so I can get the cyls select at the proper number, and have the truck start every time? I mean, I know the obvious answer is to leave cyl at 6 and BPW at 135, but I don't want that throwing off my logging and tuning and making things harder than they need to be. Thanks for the help

 

I don't think I agree with your statements.

First I always try to start with a bin as close to what I am running.
You have an old 350 so start with an old 350 bin.
But you threw a 454 TB on top? so now you are going to probably have some AE proplems to tweak.
What I have done is started with the 454 bin and just import the 350 fuel/spark tables into them.

Now for the O2????
A heated WB is not a requirement.
Do you have the O2 installed?
Where?
Are you logging data?
what codes do you have?
You need to clear any errors first then start working from there.

Go to the DIY-EFI or motes site to download the bins you need to start with.

If it won't start with the proper bin then you have other issues to work out.

Have you used the voltage checks listed on the wiring ECM pin outs?
Key on and running?

Have you done the IAC reset?

What's your fuel pressure?

Base timing?

One other OBTW...I have had intermittent problems running the V6 netres(limphome) chip with the V8 bins. Never have been able to figure out why.
But... something to keep in mind while you are playing with the bins.

 

Changing the cylinder select will change the at-crank timing. I would double check what the base timing is and also use the proper cyl select value.

As for using a 6 cylinder NETRES on an 8, try lifting out pin 9. That one seems to be a mode select of some sort. I meant to look inot this but forgot about it. Pin 9 on an 8 cylinder NETRES is infinate in resistance. Where it is 4.6K on a 6 cyl NETRES.

RBob.

 

Thanks, as always for the tip RBob.

 

Thanks for the tip, I'll try starting with a 350 bin, bump up the BPW to get it started and then do some BLM tuning and get the BLM right...

But out of curiousity, what is NETRES?

 

Why bump up the BPW? If it's a stock 350 with a 350 chip and 350 injectors?
Are you just wanting to change things in the bin?

The netres is a network of resistors that set the base fuel parameters the ECM uses during limp home mode.
It is the limp home chip next to your bin chip under the little cover.

 

I was going to bump up the BPW so the truck can be moved around the yard while I'm busy re-tuning the VE tables - when I first did the 454 TBI swap and used a 350 chip whenever I'd crack the throttle the truck would immediately go lean and die with any load at all. I'd rather go a little rich and still have the truck moveable (with the 350 tune) tho I suppose I could always just throw the 4.3 chip back in when I need to move the truck around the yard.

BTW, I said my truck has a 1227747, it doesn't have a resistor bank it has a small chip next to the Eprom socket.

 

Yes I know!!!

That's what that little chip is!!!!

I am running the 7747 also with the 454 TB.

Bottom line is your motor will run just fine on the stock chip with that TB if you have everything hooked up right and the inj are good. It will not die as soon as you touch the throttle.

It won't be perfect but it will run fine. You could allways bolt your inj back on the SB TB!!!

Now the larger size of the holes are not going to make a drastic difference unless you are trying to stab the throttle WO from a dead stop.
Part throttle will not really be any different at this point. You need to get it running with the proper chips first then start making your adjustments.


Are hooked up with a laptop and logging any data or did you just bolt everything on and start it up?

As pointed out earlier, the V6 chip and the V6 limphome(netres) chip need to be replaced with the proper ones. Or try to mod your limp home chip as per RBobs directions.

 

I would start with the 305 bin personally. It is actually closer to what a non TBI 350(would be your engine) likes to run on. It is richer in stock calibration when used with the 350 injectors BPW set at 148 in the 305 vs. 135 in the 350 ecm. The AE is also set up richer due to the smaller injectors on the 305. The VE tables are also closer due to a more even matchup on the RPM bands. 305s peak around 4,500 rpm in HP and 3,000 in torque, about where the older 350s did. The newer TBI 350s peak at about 3,800 in HP and around 2,400 in torque.