I'm in the process of tuning my 1990 and I made great progress, but there was a little something off on my fuel delivery. My VE tables were close to maxed out and I still had lean "hang ups" at part throttle and in the midrange in the middle maps (I'm running a wideband gauge all the time). I was able to tune out 99.7% of it through creative P/E and injector constants, but I wasn't quite satisfied.

I wasn't interested in the least in getting the fuel rail off so I largely ignored the injectors. I took a deep breath, bit the bullet, and picked up the 24 lb Ford "Blues" from FIC and boy am I glad I did. I was able to do it in about 2.5 hrs today taking my time and without removing the runners at all. When I pulled the old injectors, they look like the Ford/ Bosch 22lb "Orange". I was convinced that the car was stock, but I guess not. So injectors these worked great when the engine was stock, but at you approach 300 RWHP, they can't keep up with the fuel demands.

Anyway, I just did a quick and dirty 4% reduction in fuel in the tune and adjusted the injector constant. Did a quick chip switch and took a late night drive. Early results on an non optimized tune are very positive with all the fuel on tap, no lean spots, nothing quirky on the wideband. Looks like I'll be doing some more tuning tomorrow.

 

Congratulations, I'd love to view your .bin and make recommendations. A lot of people think that the learn function will make up for changes in the speed density, but there's nothing smoother than working the VE tables and having instant starts and driveability.

 

Yes, you made a very good choice. I did the same thing on my '90 earlier this summer. Well worth the effort. Before my injector swap, i had very low BLMs, (rich), and was going to attempt hitting the VE tables. After some good advice here on the boards, i looked at the stock injectors. One had a very low coil resist, and there were 3 different types of injectors on my TPI. So they were all mismatched. After putting in the new injectors, and a few other minor things, i took it out for a datalog. Without changing the stock VE tables, my BLMs came in real good! I was quite surprised. Now i am only making minor changes to it, and it runs very well.
My only advice to you would be to set the injector constant for the fuel pressure you are running, and leave it alone. The guy at FIC told me to just run it at the stock pressure, like 43.5psi. I just set to 44 and locked it in.

 

I ran a few 30 minute datalogs and 4 tunes today. The injector change put my 120ish BLMs, back down into the 90's (which is about 10:1 on the wideband). I got most of the PE in line and working my way up to 128, but my car likes to be slightly rich.

I need to look at my knock counts too after removing the EGR too. The closer I got to 128 on my old injectors, the knock count went up rapidly. I lowered by target to compensate for E10 and it seems to like that as well. My car responds well to 14.0-14.4 for cruise, 12.8-13.5 for medium throttle acceleration and 11.7-12.3 for wide PE/WOT.