hello
I have a 1993 Camaro lt1 procharged new 355 with stock ported heads 224/236 114 cam pacesetter headers, ported intake, ported tbody 42 lbs injectors. I have a pcm tune it right now with p1sc procharger 2 bar tune 12 psi pulley only see about 9.5 psi I have about 1000 miles on motor. Running pretty could first 950 miles about 126mph in quater on street tires about 485 rwhp i think. MY questin is this I have an intake oil leak and wp drive leak i think. New opti spark like 5000 miles ago accel 9000 plug wires msd coil and tr6 nkg spark plugs. I have driving it and went to WOT and the tach started jumping when I hit about 5000 rpm it was bouncing all over like something was wrong went home let it sit for about a week started it up after wiggling plug wires and opti connections and coil connnection. Hoooked up datamaster timing was at 26 to 26 degrees with tune now i am only at 22 to 23 degrees no codes in computer. I am down at 50 hp is that just frome the timing and if so why did it move. could the opti be broke and throw no codes just change timing.
thanks
ryan

 

If you get moisture from a leaking water pump on the opti it can cause problems. It might just need to dry out. You should fix the leak right away since it will keep doing it. You can check the opti while its off.

 

not leaking antifreeze just oil out water pump drive seal. I should also meantion that the IAT is in spec not off. I am lost it doesn't make since I am losing a good 3-5 degrees and it is not pulling any timing either from knock

 

What DataMaster is reading it the timing the PCM is trying to set, not the actual results. If the Opti is incorrectly indexed or if the optical sensor is producing a corrupt signal, the PCM has no way of knowing that.

But the timing the PCM is trying to set is calculated from the spark timing tables and the various offsets for other sensor inputs like inlet air temp, coolant temp, etc. The timing tables are also a function of the RPM and the MAP reading. So, if you are experiencing high inlet air or coolant temps, its likely that the PCM might not try to set as much advance as it was before. And if you have a faulty MAP sensor, you could be getting very erratic timing from the PCM. With your speed-density setup, a faulty MAP would also mess up the air lfow calculations, and throw the A/F ratio off.

The first place to check would be the MAP sensor harness connector. I've had mine dry out and crumble, and produce very erratic MAP readings. Watch the sensor readings on your scan software, as you jiggle the harness and connector.