DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
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Doing a TBI swap on my truck. Can anyone tell me what these numbers mean and what to do about it? I have attached the file if anyone cares to give it a look. I know you guys are great, I diagnosed and fixed my 89 L89 formula (bad injectors) just by searching the site!
Thanks
GCM
I took a look at your BLM WinALDL summary file. Basically your base line fueling is causing to run your engine lean (BLM >128). ECM is able to compensate by adding fuel, but this is not optimum since there are many cells that have not been used for actuall engine operation.
There are many different ways to fix this.
You can do a search.
You can increase fuel pressure.
You can change fuel injectors to a larger ones.
You can update VE tables in your EPROM. The list is rather long - and it all depends on your setup and how much you want to get into it.
Almost all of your cells are running lean. If you do decide to increase your fuel pressure or increase your injectors, you will still run into a problem. You might want to start looking into getting a Autoprom or Ostrich and hanging around in the DIY Prom site. Changing injectors will mean changing Base Fuel in the ECM. Since it appears you are only using the NB02 (Narrow Band O2) it will give you a semi-close method to adjust your fuel cells.
__________________ (ENGINE) 355 SBC - TPIS MiniRam - AFR 210 75cc Full CNC - BBK 58mm TB - JE Forged Pistons - Scat H-Rods - Eagle 4340 Crank - Crower 00482LM Cam - Vortech S/C @ 18LB - 10k RPM Nitrous Kit (TRANSMISSION) Vigilante 2600 Stall Convertor - 700R4 Rebuild Kit Pro Street Elite by Pro Built PN# PSERK70088 (SUSPENSION) Full Hotchkis Subframes - Bay Braces - Torque Rods & Trailing Arms and More!! (INTERIOR) Cyberdyne Digital Dash - Pioneer MP3 / DVD Player - (2) 1500+ Watts Rockford AMPS More Forged than plastic - Way 2 Much 2 List.. Some Say I am
Probably the two that everyone uses is either Tunerpro RT or CATS.. Both are very good but you willl find a charge with Tunercat where as tunerpro asks for a donation.
__________________ (ENGINE) 355 SBC - TPIS MiniRam - AFR 210 75cc Full CNC - BBK 58mm TB - JE Forged Pistons - Scat H-Rods - Eagle 4340 Crank - Crower 00482LM Cam - Vortech S/C @ 18LB - 10k RPM Nitrous Kit (TRANSMISSION) Vigilante 2600 Stall Convertor - 700R4 Rebuild Kit Pro Street Elite by Pro Built PN# PSERK70088 (SUSPENSION) Full Hotchkis Subframes - Bay Braces - Torque Rods & Trailing Arms and More!! (INTERIOR) Cyberdyne Digital Dash - Pioneer MP3 / DVD Player - (2) 1500+ Watts Rockford AMPS More Forged than plastic - Way 2 Much 2 List.. Some Say I am
I will give them both a look. I installed an in line fuel pressure gauge today. It reads 10.5psi constantly. I know that is on the low side, but I have a new fuel pump (1990 k10) in the tank. I have a clear plastic filter in front of the gauge. Could that cause low pressure?
Thanks
GCM
Try to bring your FP to about 13-15 PSI range. Stock TBI had FSM range between 9 to 13 PSI as being acceptable. Running higher FP improves fuel distribution - smaller fuel droplets which tend to result in better overall mixture. (There are other benefits as well). TBI injectors can handle higher FP without any problems. To bring FP up you'll need to replace TB pressure spring. Go into TBI forum and do a search. To verify that your FP is capable of delivering adequate fuel pressure 'gently' pinch return line (at flexible portion). If your gauge zooms up to 20 PSI a simple spring change will do a trick.
O.K. I increased my fuel pressure to 12psi by the method shown here: www.binderbulletin.org/forums/showthread.php?p=298293#post298293
I dont think I can turn it any farther. Should I try to get more by adding washers, or changing the spring. The increase in pressure did seem to change my BLM numbers however. Also set base timing to 6 degrees advanced. I have attached them for reference. Thanks for all the help the engine runs better now it just will not pull when I give it gas.
Thanks
GCM
Yes, increasing pressure brought your BLM values closer to 128, but you are still running on the lean side. Since you have maxed your fuel pressure at 12 PSI it looks like FP R&R time.
Get a AC-Delco unit for 94-95 TBI trucks - these can easily deliver 30 PSI - pressure regulator can easily handle slightly higher pressure.
Used a piece of wire in #1 cylinder to check TDC. The timing tab was at least 20 degrees low! Now I have the timing set @ around 10-12 degrees and now this thing is a beast! It never ran this good with a carb. It pulls hard from 600-6000 RPM. I took some more data, but from idle to WOT I can't "feel" any problems. What do you think about the new numbers? Thank you guys so much for your help! Oh yeah, don't trust 30 year old balancers or cheap timing tabs!
Thanks
GCM
Those BLM #'s are looking decent!! A little tweaking would make them better!! Seems to be a little rich in the lower map area's and myabe just a little lean in the high map area's but not bad considering you havent tuned the chip yet!! One other thing to post would be a copy of your knock counts!! to see what its doing with the timing. Just my 2c's
