Ok, specs

383 stroker motor,
306 cam,
stock heads home ported no flow numbers,
stock injectors
stock TB,
Jet Hot LT's
true duals through bullets dumped at axle.


I mailed out the computer to have it tuned. Finally got the engine back in the car. Car starts and runs, but on datamaster it's pulling serious knock and retarding up to 10. A/F was too low to even read on the wideband dyno. Took 1/4 tank of gas to drive 30 miles. IS the A/F b/c of tune? knock retard? Combination? How can I figure out if it is false knock coming from valve train and duals or true knock.

I'm thinking it is a combination of tuning and retarded timing, but wanted to ask some of the pro's.

 

1) You can not tune an engine/car thru the mail. Many people have found this out. Whoever is doing the tuning, they need the car for awhile. The first thing to tune is the idle and part throotle driving, then the WOT stuff is last.

2) What computer are you using? Any error codes? What is the idle RPM, etc? What is the WOT O2 readings?

 

Computer = stock PCM unless you mean laptop and in that case, I have halted using my laptop b/c the battery pack has shot craps and the last time I tried to edit the file with LT1 Edit I erased the PCM due to a spike from having it plugged into a 12v source.

As for error codes...all I have are DTC codes 15,36,41,44,83

15 = cool temp low
36 = Hi-res fail
41 = EST Open
44 = left O2 Lean (once in closed loop)
83 = Reverse inhibit circuit fail

Idle RPM is consistent 825-900 RPM idle tune seems OK, WOT is where I have the most problems

Highest o2 readings @ WOT is 941mv

I'm thinking I just need to get my 58mm TB and 42lb injectors in there then take it to someone in person for tuning. I'm thining about heading down to Tulsa because I don't know of anyone in the KC area who I truly trust to tune this.

 

Well, I asked about the computer (I do mean the ECM/PCM) because from you wrote and your username, one might conclude that you have a 1967 Camaro with maybe an '02 LS1 engine. No where do you indicate what car you have , what year, etc.

How you treat an OBDI car is different than an OBDII car.

 

I apologize, this is OBDII 94 Z28

 

You mean obd1 94 z28?

 

Apparently I didn't get enough sleep, you are correct it is OBDI. I must have benn typing too fast.