Long time lurker, perhaps first time poster? This forum has been so helpful to me for years. I love this place. Anyway, Grimm from Atlanta here. I do have a 1982 Firebird SE with a 383 Stroker and TH350 that's carbureted. But today I'm here to humbly ask for some guidance from those who are smarter than me with regard to both timing my engine and tuning the EBL FLASH II system in my 1990 C3500 1 ton dually pickup. I hope that's ok... The engine is a fresh build, though this truck had a 454 in it from the General once upon a time before I owned it. I am a technically savvy journeyman mechanic, but tuning fuel injected stuff is all new for me and I'm at a loss.

I'll start by listing the engine specs. It's a big block 454. According to the build sheet, the engine was built with:

• eagle CS 4" Stroke crank
• king racing xp rod & main bearings
• forged I beam connecting rods
• speed pro coated skirt pistons 10:1 comp
• comp extreme energy cam
• high volume oil pump & pickup
• 2.19 - 1.880 stainless epr valves
• cast oval port heads (stage I port & comp valve job)
• 10 degree moly retainers and locks
• 924.16 comp springs
• roller rockers
• Hedman mid-length headers
• standard 454 tbi throttle body for this year truck

From the printout provided, I can see that the engine builder was running this at 18 degrees BTDC on the "run stand". I don't have much big block hands on. This seems like a lot of timing to me, and the engine doesn't seem to like it either.

• My first question is: what should the base timing be set at for this engine realistically? The original emissions diagram on the air cleaner said 4 degrees BTDC.
• My second question is: besides setting the base timing setting in the BIN, what else do I need to adjust?

I began with the 1 ton truck bin (EBL_F_2013).I disabled EGR in the bin, as this is not in place. Is there anything else that might be relevant to the tune that is important, which I might be overlooking? The charcoal canister is still there if that matters. Lastly,, it had been indicating MIL code 33 as "on" for the brief time I had the truck running.

The transmission is a TH400, though I'm fairly confident that it's nuked because its currently only got Reverse and three neutrals... but that's another story for another day.

Thank you so much in advance for any/all wisdom which you can share with me. My truck and I appreciate it.

 

I'm not ultra experienced on ebl but I would probably leave it at 4* or 6*. Initial doesn't change things much as you'll be changing the the actual advance in the tune. The only reason I personally know to advance intial is if you need more total timing than the distributor can move on it's own. Past that, you'll be changing/remapping the advance tables in the bin, that's what it needs. Same as you would a mechanical dist, just with numbers instead of springs and vacuum canister.

 

the initial/base timing in the tune is different then what the engine will have when idling. 15-18 degrees at idle as seen with a timing light doesn't sound to high to me?

just incase you had missed that detail
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Thank you for your reply. So we set the timing by first disconnecting the est wire (brown with black stripe I believe), then we established 0 BTDC, and then finally, using a timing light, we set timing to 16 BTDC and modified initial SA in the tune to match that value. It ran rather poorly. What am I missing?

 

I don't have a flash 2 but that sounds incorrect..

try disconnecting that wire, start it, adjust the distributor to set the base timing to what is in the tune under base timing, usually 6deg. adjust your distributor with the wire unplugged till you get that 6deg. then turn the engine off, plug it back in, start and then pull up your scanner, see what timing it says it's running at, and double check with your timing light that your are seeing the same as on screen.

your timing should now be synced so the ecm can control it correctly. the base timing is the timing used during cranking and below something like 400 rpm. once started, the ecm takes over and runs what is in the tune.

 

To be fair, we had been messing with the timing a bunch, trying to get the initial sorted out with the tune. 16 degrees was the last value we set it to, since I did notice the builder had the timing there on the run stand. The whole situation has me twisted around second guessing myself. Not more difficult than a carburetor, just a slight learning curve.

I'll attempt the process as you've outlined asap and we'll see how it goes. Again, thanks for taking the time to help give me a pointer. I'll report results on this. Hopefully (though I highly doubt it) having engine timing set correctly might eliminate my MIL #33 too...

 

good luck with it. what's code 33 on the flash 2?

 

I believe it's the same on all ALDL systems:

MAP Sensor Circuit Error (Signal High Indicating Low Vacuum) Low voltage would indicate high engine vacuum and lower engine load. The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

 

ahh that makes sense. timing isn't that sensitive at idle but map can make the whole thing bearly run.

just as a test you might try unplugging the map and see if it runs better. sometimes the default settings are better then incorrect map data. but just a guess