91F150

I was wondering if there is anyone here that could help me out using this thing? Sorry, but this is a long one.
We're using it on our '91 F-150 2WD. The truck originally had a 302 and we just swapped in a 351. It was bored .040" over, KB forged pistons for about 9.5:1 comp, HO roller cam, gear drive, ported World Products Windsor 200 heads, 1.6 RR, Venom 21 lb. injectors, Mallory FP reg., Prof. Products billet fuel rails, truck 351 lower ported to match heads and to the stock 302 upper truck intake, BBK 56MM TB, Hedman Elite Long tubes, and Edelbrock STS cat back. We just about replaced everything on the truck but the transmission, that's next. We are also using a Lightning C3P1 computer.
Without the tweecer, it sorta runs. Idle and wide open throttle are all good. Basically, open loop is OK. Sometimes it seems idle is a little lean though. A/F ratios look good. We are using Inovate's LM-1 and auxbox. I'm sure there's more power to be had with changing the timing, but that's for another time. But closed loop is a problem. A/F ratios are way lean, like the upper 15's & up. It has a miss in it and stalls sometimes. Not really drivable. We double checked everything mechanical (plugs, timing, vacuum leaks, ect...). So, I got a Tweecer R/T.
With it, I entered the new injector size, pulse width, and displacement.
Ran the truck again. I think the idle needs to be readjusted but it runs much better. OL runs a little richer but the truck seems to like it. CL A/F ratios are also much closer to the "correct 14.7". Mostly bouncing between the 15:1 to 16:1. So it's still a little lean. Doesn't seem to miss anymore. But, we don't have much running time on it yet, maybe about 15 min. It seems to be drivable now. Now my problems....
It seems most info on-line about the Tweecer is mostly for Mass-Air Mustang computers (A9L). Most of the A9L features on CalEdit don't even correspond to our C3P1. So my questions are....
1) Where and how do I adjust my CL fuel ratios?
2) Why can't I adjust my speed limiter? Only the stock setting works. Whatever I put in, it changes it to a lower speed automatically. For Ex: If I save 150 MPH, go back and read Tweecer to check, it has it set at 22 MPH. And on the road, it's pretty accurate. Maybe 25 mph, but close enough.
3) Why doesn't the Tweecer always save my changes? When I read it to check my work, the numbers are all different then what I entered.
I've got more, but I'll start with these. I'll appreciate any help anyone can give. Thanks,
Chris

Super Glide

Try an injector scaler value of .005555555, a injector minimum pulsewidth of .0006. The closed loop A/F's are corrected by tuning in the correct injector scaler.For speed limiter input 127.5, that will turn it off. Make sure you press enter after every input, and above all read the manual.

Steve

91F150

I'll give that a shot today. Thanks.
I read the manual and to be honest, it's a little confusing. Then again, I've only had this thing for a few days. Besides, alot of the info it has is all about mass-air EEC's (A9L's). As far as the injectors go, it talks about slopes, breakpoints, and pulsewidths. All the C3P1 strategy in CalEdit calls for is size and pulsewidth. So alot of that does me no good.
How did you come up with that injector scaler? In CalEdit, it ask for pounds per second. So using 21 lbs/hr, I came up with .005833 (21/60/60). Did I do something wrong? Is it possible to "adjust" that scaler to change the A/F ratio? You said to try .005555555. If it doesn't work, can I change it up or down to get to my target A/F ratio? For ex: .005600 or .005400.
Thanks again,
Chris

marc2000gt

Your number for the injector scalar is right. From what I have seen, if you use the number that the math gives you, it seems to run a little lean. You lower it a little to richen it up. You can just take the injector number and divide it by 3600. It will give the same result at the 60/60.

Yes you can change it up to lean it or down to richen it. Just do it in small steps and give the eec time to adapt.

As for the Tweecer definitions for us, yes it leaves a lot to be desired. You have to do a lot of reading. There is a good Tweecer forum in Yahoo Groups.

__________________
1994 Red Lightning #1134 383ci by PSI, S-Trim, Trick Flow T/W heads, Trick Flow Box intake, 60lb injectors, Struckby Two Pump Trick, MSD 6AL, Flexalite 295's, Pickrel Magnaflow Exhaust, Art Carr 2800 stall converter, FTVB, LFP Traction Bars, Struckby mass air wiring, PMAS HPX Mass air sensor. Tweecer RT, Wideband Commander, Binary Editor, EEC Analyzer.

Super Glide

Exactly, I richened up the injector scaler, keep going in that direction until your closed loop A/F's get into the high 14's low 15's.
There are not any low/hi slopes in SD just the inj scaler and min pulsewidths

Super Glide

Chris, If you join the NLOC the info to tune SD can get much better
$30 is a small price to pay.

91F150

Thanks sstock & marc2000GT. That's exactly the help and info I've been looking for. SStock, I tried those numbers you gave me and I think they are pretty darn close. I need to go a tad richer and I think it'll be good for now. We just want this thing drivable right now so we can break the motor in.
Another question I had is, would there be any benifit the lessening the tip-in spark retard? Or eliminating it altogether? Seems on take off with light throttle, low end is kind of mushy. I was thinking about turning up the distributor timing. It's on 10 degrees right now. I was going to wait until my A/F ratios were where I wanted them with all the stock settings first. What do you guys think?
As far as the Tweecer not saving my info, I don't really know how all that works, but I deleted CalEdit and reinstalled it and it works fine now. Who knows?
I think I will join NLOC. I'll look into it next week. I've got lots of questions on tuning our truck. After I get a "stock like, drivable, tune" to fall back on, I'd love to tear into this thing.
Thank again,
Chris

marc2000gt

I set the spark retard to zero. Leave your base timing set at 10 degrees and use the tweecer to control it. You can make the adjustments in the base spark table.

__________________
1994 Red Lightning #1134 383ci by PSI, S-Trim, Trick Flow T/W heads, Trick Flow Box intake, 60lb injectors, Struckby Two Pump Trick, MSD 6AL, Flexalite 295's, Pickrel Magnaflow Exhaust, Art Carr 2800 stall converter, FTVB, LFP Traction Bars, Struckby mass air wiring, PMAS HPX Mass air sensor. Tweecer RT, Wideband Commander, Binary Editor, EEC Analyzer.

91F150

By "base spark table", do you mean the "spark_MBT_table"? So how would I go about changing that? After looking at it I think I might have an idea. To get the same performance as setting the base timing to 12 degrees, I would keep the stock 10 degree base timing, then go to the table and add 2 degrees to each number in the table. Do I have it right? I'm sure it can get more complicated then that, but have to keep it simple for now. Let me know if I'm way off!
I also got my A/F ratios down to where they need to be. I finally settled on the injector scaler of .005017. The Tweecer did recalculate it to .0050168though. But it works. Now that I have a good base tune, I think I'll be messing with the timing tomorrow.
Thanks,
Chris