Cadillac Powertrain Control Module (PCM) Tuning Discussion, Has anyone tuned a 4.9 Allante? in Cadillac Engine Discussion; Well... That's essentially what it is.
I have a 4.9 in a Fiero. A couple of months ago I installed ...
Well... That's essentially what it is.
I have a 4.9 in a Fiero. A couple of months ago I installed an Allante intake manifold (and the steel rocker supports, of course.)
I imported the fueling and timing tables from the Allante bin, into the 4.9 bin. EGR has been disabled (since the Allante doesn't have it.) I also took into account that MAT sensor is up in the plenum and not in the lower intake. (Used the Allante temp/VE correction table.)
It goes like stink, but I have a ping that I *can not* get rid of. It's in a very narrow set of parameters. BLM cells 18 and 24. (70 - 95 KPA and 2400 - 2800 RPM.) That translates to fairly heavy throttle, but not WOT.
I have added fuel up to 100% VE, and I have taken at least 10 degrees of advance from the timing tables, and combinations of the above. I even tried backing off the base timing to ~TDC. It just runs like kwrap, and still pings. BLMs are running 124-130.
The problem seems to be better (although not resolved) once it's good and hot.
My fuel pressure is running about 38 lbs at idle. Unplugging the vacuum from the FPR results in ~ 43 lbs of pressure.
The injectors are brand new (remanned) 19# Bosch type IIIs. Matched set.
I'm using TunerCat and the NS1 mask. The base 4.9 broadcast code is BWYH.
So... I think I've covered all of the usual stuff.
What am I missing?
Is it possible that my PCM is just bad? (It's a 2240.)
Helluva first post, eh?
(Oh... I've already had someone try to sell me back the preliminary "hybrid" bin that I gave him. He didn't know it was me. Gotta love that. )
Looks like I don't have enough posts or longevity to send a PM.
I can't find your email.
If you'll send it to me at shamilton2mindspring.com (replace the obviously wrong character) I'll send you whatever bins you want.