Anybody tuning these guys?

Not sure if this is the right place to post, but I'm gonna go ahead anyway.

I recently put the TBI back together with the 14lb fuel regulator spring (For the horsepowers, you see).

As you guys could've seen a few miles away or smelled anyhow, the car ran really, really, REALLY rich. 11mpg kinda rich   . But it ran, so no huge worries.

I decided to get a winaldl cable, chipburner and the modern chip adapter gear from Moates, and I've started tuning.

So far, I've adjusted general things and mileage is back up to 18mpg on the highway cruising at around 75mph. Not bad. This is with the 3.23 gears too so I'm not unhappy. Best with the LT1 wagon with 2.56 gearing was 22.

I still need to add back in the highway lean spark mode as well as who knows what else to get it running as close to perfectly as it can. It's been a fun journey that's for sure. The only problem is I can't find too many folks tuning these TBI units for cars. Most of the stuff on gearhead-efi is geared towards the trucks. It's fine, I've learned a lot, but it's no fun poking around in the dark to see what the car is doing.

Anybody else here been tuning their toys? I know I could just mail order one, but this is more fun! (I think, or I like punishment   )

thirdgen.org or is it third-gen.org? Anyway lots of F-body guys with tbi units so they are REALLY similar to our TBI cars. I know alot of B body owners hang out over there too (I did for a bit, but sold my TBI and all LT1 now).

I tuned the crap out of my old '94 RMW. That plus the 2011+ Mustang GT fuel injectors I added made it run absolutely fabulous. Transmission tuning on the E-model 4L60 transmissions also helps driveability a ton.  It took oodles of time but it was a fun experience. The stock LT1 B-car tune left a lot of room for improvement so it was rewarding in that sense.  Newer engines' fuel management systems are much quicker to self-optimize so there's not as much gain there, and of course LT1 tuning can be done for dirt cheap. If someone were to start tuning now, you need to start reading books first. Greg Banish's books are a great place to start. If you can't explain the importance of injector nonlinearity characterization, mass airflow sensor placement and intake tract design, and O2 sensor placement/thermal characteristics, don't start tuning.

How hard is it to install a TPI unit on the '91-93 engines?

LT1 seems to have been better set up from the factory. The timing tables on this TBI have been bizarre. Even after adding in PE timing at WOT I had maybe 25degrees at 4500rpm 22 or so at 3500. Either GM was getting emissions requirements taken care of, or they were making sure they're grandpamobile wasn't faster than the Camaro with a 305 yet similar horsepower.

I'll look into those books as I'm sure I'm leaving a lot on the table. Thanks!

What software are you using for tuning?

I'm using Tunerpro, seems to work ok

Let me know let what xdf file you are using, and send your latest bin to me at lakeffect@gmail.com.  I will open it up and take a look at it. Gm seemed very aggressive in reducing advance under load. I tune a highly modded TPI system, using speed density,not MAF using Tuner Pro RT. Most parameters are similar, so I might be able to help you

Thanks so much!

I'm using the $62.xdf and 62.ads. I'll send you those as well.

Thanks, headed out of town, so no hurry. First chance to look at it will be Monday evening.

no worries! It'll be great to have it looked at. I'm getting closer on the timing (I think) but not seeing any knocks yet, so I'm not sure if the sensor is busted, or I'm not giving it enough. Going to run this for a tank (probably till Wednesday) before I switch anything else.

It's finally doing burnouts again with it's nice tires so I'm getting happier. I don't do it much, but when i went from the pep boys tires to the michelins the "fun" factor of the car went away a bit.

Join the forum at thirdgen.org. there is a wealth of info that cab help you with TBI tuning.

Already there! So many folks! A lot to filter through! Damn near everything you'd want to find out!

Got the file, had a few minutes to play. Check your email.

Thanks so much! Looking forward to understanding what you did! That and testing the tune!

If you figure out what I did, let me know, so I can understand it too.

Haha, well, so far it's running good! Only ran a short errand, but it seems to like the timing. Haven't done any pulls so I don't know about up high. (I need a wideband anyhow)

Looks like you mainly smoothed the hell out of everything. That got rid of the hot starting stumble it had, so that's awesome. It's had that since I've had it.

I wonder why you dropped the part load advance from 42 down to 36? I thought (old school mechanical thinking) that a vacuum advance would add somewhere from 10-15 degrees at part/no load for fuel economy.

Everything is running happy though, so I'll run this for a tank or two before I tweak anything else.

Thanks again!

It isn't so much that I dropped the low load timing as much as I brought up the high load timing up from 18. It can likely take a little more before it pings. I have around thirty, no knock.

The low load, high rpm only comes into play when you are at higher rpm and take your foot off the gas. It is there to help burn off residual fuel.