87 ECM, LT1 MAF & Translator Upgrades - Before and After

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
What's the stock MAF reading. What's the LT1 MAF reading. Post both please.
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
Your first post you said your BLM's with the stock setup are 128 plus or minus 10. So what are your exact BLM's at idle in Park warmed up with the stock setup.
 
Your first post you said your BLM's with the stock setup are 128 plus or minus 10. So what are your exact BLM's at idle in Park warmed up with the stock setup.
Scooby - I'm back to my 87' ECM setup and currently away from my garage. I can swap back to the 85' setup but I will take some time. Can you view the ALDLdroid files if I sent them your way? Or better yet, let's hold off on until Eric sends me the replacement LT1 MAF. Thanks
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
Wait for the new MAF to arrive. I'm not sure if I know how to read that type of file. You said your idle BLM's were plus or minus 10 percent from 128 for the 85 setup. Without an exact number at idle, it's tough to tell what's going on. The BLM number shouldn't vary at idle.
 

TurboBob

Resident mad scientist
Staff member
erics chips lock the BLM at idle, but only after they have run one cycle to 'learn'. if you make changes you should reset the ECM so the idle BLM can relearn. For a 3" LT1 MAF, Base should be set to 3,4, or 5.
 
If you look at my Scanmaster vid, you'll see the BLM's steady at idle.
Here's a snapshot of my ALDLdroid files, before and after, showing histogram (engine speed vs MAF (BLM))
 

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SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
Bob makes a good point that you have to let it learn. Follow Erics instructions to the letter. On the first cycle I've always found the RPM's to be all over the place cuz it's learning. After a couple of cycles I take it out of town to a long stretch of country road and slowly bring it to WOT to learn the full RPM range. I tend to be overly cautious. If you have the 3 inch LT1 MAF set the base knob to 3. Don't panic if the BLM's are in the low 120's. Over 128 is pointing to a lean condition. Note my engines ran at 122 on Erics default and that's where I left it. Make sure you always have a good 02 sensor. I always used Densos. The 02 sensor reports back to the ECM for fueling.
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
I was prolly one of the first to run the Z06 MAF. At the time it needed a 3 to 5 pin connector. I was installing the new CAI setup. I unplugged the ECM power wire to play it safe. I fire the engine up and it starts running shitty from an RPM standpoint when the fan kicked on and sputtered out. Wouldn't do dick when I tried to refire it. Upon inspection I had plugged one of the MAF wires upside down. Corrected it and all was good. I don't know if this is possible for your setup, but have a look. Also send that file to Eric to look at if you haven't done so.
 
I was prolly one of the first to run the Z06 MAF. At the time it needed a 3 to 5 pin connector. I was installing the new CAI setup. I unplugged the ECM power wire to play it safe. I fire the engine up and it starts running shitty from an RPM standpoint when the fan kicked on and sputtered out. Wouldn't do dick when I tried to refire it. Upon inspection I had plugged one of the MAF wires upside down. Corrected it and all was good. I don't know if this is possible for your setup, but have a look. Also send that file to Eric to look at if you haven't done so.
Scooby-Doo: I received my new replacement LT1 MAF and installed it last night. I brought the car up to temp and went for a short drive (10-15 minutes). I made a couple of stops (engine off) around the neighborhood and then called it a night. BLM behavior did not change from previous with cruising BLMs at 133-136 and idle BLMs at 142.

This morning I reset my ECM, brought the car up to temp then went for a long ride. City streets followed by a freeway run (BLM behavior was as before for this run). I made 1 WOT pull and hit 11PSI. Getting into some boost to merge I noticed my boost gauge flutter around 5 PSI.

I exited the freeway to make quick pitstop and noticed that the car would begin to stumble as I came to a stop. I kept on the gas and returned to the freeway (far from home, needed to head back). Getting up to speed for freeway action I noticed a loss of power and a fluttering boost gauge from 1-5LBS. I didn't get into any boost for the remainder of the trip.

I made it home and have not been able to get the car to idle like it did before and now it just won't stay running.

What could have gone wrong? (Scanmaster G reports no codes)
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
With the BLM's at 142 at idle means it has a lean condition. My guess is it leaned out at WOT and blew the head gaskets.
 

Pronto

Believe nothing you hear and half of what you see.
Check you couplers first but it does sound like you lifted a head enough to do damage to the gasket.
 
Run a compression check. I accidently overboosted two engines and the gaskets blew outwards. No coolant loss and no overheating. Your BLM's were telling you it was lean. WOT was asking for trouble.
Bonehead move (no excuses) for sure. I had no problems running my original ECM and MAF but wanted to get ahead with an upgrade now so that I could continue learning but boy, blown HG was not a path I wanted to venture into.

I did a compression check for all cylinders and here are the results:

81,500 mile stock engine

Cylinder 1 = 133 PSI
Cylinder 3 = 140 PSI
Cylinder 5 = 133 PSI
Cylinder 2 = 133 PSI
Cylinder 4 = 0
Cylinder 6 = 133 PSI

Also attaching picture of the pulled autolite 25s (.35 gap, order 6->1)
 

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