Made a thread on advanced tech with on one reply & hoping to receive some more feedback here since I'm running an ATI Procharger.

96 LT1 383 Forged Bottome end 8.5:1 CR
P600B 6 lbs boost
Ported LT1 Heads, Edelbrock Throttle Body (not sure what size)
55# Injectors
373 gears, T-56
MSD 6AL with Accel box under passenger seat (not sure what this is yet)


Just bought this car 3 weeks ago. I've been playing with high performance mods for years, but never and EFI set up (it's gonna be fun!!). The car obviously has a very rich tune as it burns your eyes and just smells gassy when idiling. Took the car down the highway for the first time and reved past 5000 rpm's for the first time through 2nd, 3rd & 4th gear...... car pulls hard!! When I pulled off the highway and the smoked WHITE out the tailpipes and has a miss now.

I'm running 55lb injectors ARE THESES TO LARGE?? What size is recomended??
Will my rings reseat??

 

Make sure the injector constant in the ECM is set to 55. Sounds like it needs a tune. You CAN make big injectors idle and cruise lean, but the tune has to be right.

Mike

 

Well I hope the white smoke wasnt coolant coming out from a blown headgasket. Did the previous owner have the car tuned at all? It would be pretty dumb to just throw in 55s and not tune the car since its double the stock injector size (talking about previous owner). See if you can talk to him and find out about the tune.

 

I have been running 72# Seimens Inj peak_hold type with and Acceleronics box. I previously had 2 cyls lock fdue to excessive fuel inout during cranking. Caused by 2 transistor outputs grounded together in the box (sent back for fix). Pulled the plug to relieve the fuel in cyl (it was alot of fuel). Also the oil was fouled with gas (drained). Sounds like a head gasket failure. I've been using felpro 1074 for years with no issue. The PCM will not drive peak_hold injectors since they require much more current flow to operate (stock = saturated voltage type inj). Hope this helps. B. (97ss 383 - D1 M6)

 

mz, ever since I installed my acceleronics impedence converter and 84's, mine has cranked very rich. In warm weather, I have to hold the throttle open to get it to start. At all other times, it runs good A/F. Do you think I have the same problem?

Mike

 

Yes, I did have rich afr @ engine start. Since the car starts in open loop mode, I changed all the open loop afr fuel map down_low (leaned out). This helped alot. I also lowered the low rpm vol_eff table lower (in the fuel menu - LT1 edit version 2,2). Now it starts quite easy (maybe 1 to 2 seconds since, I run 3 springs on each valve & alot of cranking torque). Previously, it would start very rich. It is my opinion, the gm obd2 pcm is not designed for these large injectors and the MAF cannot be made to work unless the cal curve is altered (with large ingestion of air). I have a wide band Dyno_jet and this really helped me along with the LT1 obd2 S_ware ver_2.2 upgrade. I notice that these early obd2 pcm's have a very slow afr update sample rate. The afr changes rich when you lift on the throttle @ low speed rpm (<3k). I also reworked the bypass valves so they worked better. I had alot of trouble with loss of measured air. The gm obd2 pcm is hard to tune for my app, and, my opinion is they are a difficult tune for what I am doing (Fast xfi much better, but $3.5k). But now I have had success by playing alot. B.

 

How rich are you guys talking about @ idle w/ the AFR's? 11.5-12.0 rich or are you guys higher? Just wondering.

 

Open loop average afr 13.5 @ idle. Closed loop steady 14.7 afr @ idle. B. (97ss - 383-D1)

 

Well I attributed my AFR's to the RC inj's. I just traded w/ a fellow member for his low Z Acceleronics 96's. Should have them before the weeks out. I'll see how they do.

 

SRZ... I see you run a FAST Xfi. It took me a long time to tune (via. LT1_edit 2.2) my combination with the stock gm OBD2 PCM (97ss). ie... AFR dialed in for closed loop and PE/ rpm mode. Your car looks great. Been thinkin of going to FAST Xfi. B.