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Getting Started: LO3 Camaro

There's a ALDL app. ALDLdroid. You use the Tunerpro masks and data streams but there's an issue with it right now on the file side where I can't load any updated files to it.
 
*I forgot about this thread so I'm moving my post from the other thread here.*

I replaced the intake on my Camaro with the Edelbrock Performer TBI piece, rebuilt the throttle body with new injectors, injector pod spacer, JET adjustable fuel pressure regulator, ground off the air horns and installed a NOS GM distributor.

My timing hopping around at idle with the timing connector unhooked is gone, it starts and idles pretty nice now and runs good. I have lost some off-idle power which I've read is a common thing with this intake. I'll eventually regear and put in a more aggressive converter so for now, I'll live with it.

My issue is fueling. I was watching the live stream and looking at my BLMs. They should be around 128 counts for stoichiometric but it is running in the 105-112 range pretty well across the board. No big deal. I've probably got the fuel pressure set too high. So I started lowering the pressure and with it so low the car stumbles and is noticeably down on power, my BLMs are still the same. I turned it back up till the stumble was gone and have been driving it some to let it settle in more.

So now I'm curious if that's a common range for the BLM to be in on a fairly stock 305. That's around 12-15% fueling being pulled by the ECM.
 
I scored a '427 ECM from a 1995 pickup at the you-pull-it yard for $10 and last night I got a deal in a Moates APU1 package so I'm going to try to back probe and bench test my ECM then go straight to the ECM swap if it's good.

With advice from Dave from GearHeadEFI and Eagle Mark's (RIP) repository of calibration files, I started with a BHMD 5.0L/4L60E calibration file last night, using the compare feature in TunerPro to add the AIR stuff from a BHMX 5.7L/4L60E California truck calibration.

I think I was able to disable the 4L60E stuff and set it up for a TH700R4 as well. Next is to get the IAT enabled and set up. TunerPro doesn't like to compare bins from different ecms, figured that out with a bunch of "undefined"s in the compare box last night, so getting some of that transfered is going to be tedious.

Progress. Slowly.
 
That's cool! Yes, we were lucky much of that data and information is still available to us. Unfortunate Eaglemark was taken so soon, he was a resource all his own.

But it's heartening to see much of what he had learned still has value.

The whole tuning process is kind of tedious with these things lol. I've got a good tune, burned it, and had something corrupt, and have to go back and transfer all that data to a clean image and re-burn. Right now I've got a rev limit that I know I didn't enable lol.

Not a huge deal for something driven a few thousand miles a year at best, but when you've only got three usable gears, and need to get onto a 70MPH freeway towing a trailer, hitting a rev limit at just over 3000RPM isn't helpful.

I'll probably do the copy/paste of all the data to a clean image again and see if that cleans it up. I also want to enable lean cruise but at over $5 a gallon I have little incentive to burn fuel just to work out the kinks in tune to save a few MPG.
 
Popped open my 7427 last night.

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Was busy helping the middle girl with a wood working project for spite so didn't get my pinout figured out just yet. I want to bench power it and try to talk to it.
 
I've been trying for a couple days to power up the ECM on the bench and talk to it. Tonight I got it to work. I had my powers and grounds right and had the right data stream wires, but had them hooked to my ALDL connector incorrectly.

Tonight I got it right and was able to get the data stream from the ECM. I watched it set the codes for the different missing sensors (no harness, just jumpers to the wiring) as it detected low voltages from them. Everything seems ready to start repinning.

I also removed the IAT/MAT from my BIN and burned a chip for it. Hopefully I'll find time to repin the ECM this weekend.
 
I figured out my BLM issues. CFM Technologies lists the injectors as 5.0L injectors but then says later they are actually the injectors for the 5.7L. Now I've got to change my injector rates for my new BIN.

I've still got to get a 1995 knock sensor and double check the pin-outs for the ECM swap.
 
Got the driver's side torn down to put new KYB struts in and the new KYB strut mount is trash. Bearing is loose in the stamping and the rubber isn't even bonded to the outer shell.

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OK. Camaro is back together and running. I need to get it aligned but it'll drive.

I swapped back to my OE injectors and my BLMs were still around 110 so it's obviously a fuel pressure issue. I ordered a CFM Technologies fitting for a fuel pressure gauge but while I'm waiting I swapped back to the CFM Technologies matched injectors. I know O2 voltage isn't a very accurate way to tune but figured it would help me rough it in. I was in the 950-1000 range with the OE injectors and struggled to get to 4000RPM.

When I swapped back to the CFM injectors I dropped the regulator two full turns and then made a couple pulls.. That dropped it about 25mV so I dropped it down another turn and a half. It's almost completely turned down now and then I made a pull. That got me in the 900-950 range and it will pull through to 4800RPM easily. It will also spin the tires from a dead stop again.

When the fuel pressure setup gets here, I'll verify where it's at. This car seems to be an anomaly as most folks have to turn the pressure way up to get it run good.
 
Installed the fuel pressure gauge and it's steady at 12psi.

I don't understand how I can be nearly 15% rich pretty much across the board with factory injectors and 12psi, especially with the Edelbrock Intake and TBI mods that are supposed to increase air flow.

Is this intake just that bad at holding the fuel in suspension and I'm slugging the cylinders with puddles of fuel that won't burn?
 
What do the spark plugs tell you?
I haven't pulled one but being EFI I would imagine they'll tell me it's running fine. The BLM is the old term for Long Term Fuel Trend. It's pulling ~15% out of the fueling to maintain stoichiometry in closed loop. So the engine is running correctly fueled in part-throttle driving.

Going WOT, it felt bogged down. Years of carb tuning experience told me it was a rich issue and not a lean one and the O2 voltage agreed. Turning down the fuel pressure which in turn reduced the injector flow both allowed the engine to turn higher RPM easier and lowered the O2 voltage during the pulls.

If I had a vacuum leak of some form, the ECM would be adding fuel, not taking it away. If there was an exhaust manifold or O2 sensor leak, it would still read lean (extra air in) and be increasing fueling instead of pulling it.

That leads me to too much fuel flow, which I've now verified it's not using the original injectors and lower-that-factory fuel pressure, or I've lost air flow. Nothing changed except the intake and removing the ridges off the throttle body.

I looked at some old data logs from this car from before the swap and the fuel trims were perfect. It runs great and drives great, it's just pulling fuel in Closed Loop and rich in WOT/Open Loop.

I don't think timing could cause this much of a difference but I'm going to warm it up this evening and verify my base timing is still correct and I didn't accidentally bump the distributor.
 
If it was good before, the changes in the intake flow would be where I would be headed. I still check plugs on EFI. But I am old.

Maybe the turbulence from the ridges in the TB was there for a reason?
 
If it was good before, the changes in the intake flow would be where I would be headed. I still check plugs on EFI. But I am old.

Maybe the turbulence from the ridges in the TB was there for a reason?

Possible. It's much less change than removing the choke horn on an old Holley and has always been touted as an improvement.

I will try reading the plugs to verify but everything is pointing to rich and leaning it out improved the performance.

I've honestly never read the plugs on anything. I've tuned by feeling. Knowing the difference between a lean run-out and a rich nose-over hasn't really failed me yet. But we're not talking huge horsepower competition engines either.
 

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