freebird01

I have done countless research and yes, i have used the "search" button to no avail! i have the p0300 code every day, I have a cammed 01 ws6 with 143xxx miles and has larger injectors, 255 fuel pump, new filter, hotwire fuel pump re-wire, brand spanking new AC Delco spark plugs (25 miles) wires are new, coils all tested good. the cam spec is 224/224 563/563 114 lsa thunder racing, with titanium retainers and 7.4" pushrods. it has been tuned by the previous owner at a shop called PBJ (performance by Joe) <sounds like a sketchy shop>.... Anyways on my 5 hour ride home from iowa where i had bought the car it felt like it hit a brick wall and the SES light starts blinking, I stop the car check under the hood and see if something came loose and nothing seems out of place. It seems like its random when it happens hence the p0300 random misfire but what it feels like is if im on the highway at a constant speed (i work 26 miles away from my house and all highway) it will happen. it seems like if im accelerating part throttle it will go no where until i get half pedal and then it jerks and feels like its running correct. I have tested everything from compression (190 all across the cylinders except #8 which was 175psi) i replaced the spark plugs and even checked the gapping on the old ones and they were ALL different, one was even touching the electrode WTF! i tested fuel pressure at idle and that was 75 psi, tested each injectore and they all dropped 30psi when energized. i had 2 vacuum leaks which were the pcv hose into the intake, and the pcv in the back of the engine that crosses over from bank 1 to bank 2 with that rubber Y. I fixed those and then checked my Fuel trims and if i remember correct they were close to -4% bank 1 and 19% bank 2 (these are LTFT) but dont quote me on that, before the vacuum leaks were fixed it was +55 on 1 and +35 on 2! I fixed the vacuum leak and did a Fuel trim reset and drove 40 miles home and no lights came on, this morning i went to work got 20 miles from home and the SES light started blinking and the part throttle no accel started acting up again! Im stuck!!! HELP ME PLEASE, im running out of things to test, im not sure if the person that tuned the car didnt tune it right and forgot to change the misfire sensitivity table or what, i am at a loss! I forgot to mention that the car drives just fine and there is no loss of power or even seems like it is missing if the SES light comes on and doesnt blink, just when it blinks is when there is no acceleration.

I have screen shots of my scan tool from diagnostic data if there is any more information you need (iat at idle, maf Voltage/g ETC)

freebird01

Driving home yesterday had issues within first mile then blinking ses light went away, here is data from when i got home

Ltft bank 2 -1.5
Ltft bank 1 8.59
Map 38kpa
Iat 18°c
Coolant 79°c
Cam signal low- xxxx
Cam signal high- xxxx
Maf 7 g/s
Iac position 54

The weather was about 16°f i have no clue how to change the settings on my otc scan tool to English units rather than metric

J_O_E

I am the best person for this issue. Just look at my name. PBJ.

Anyways, have you taken the scanner with you and run the diagnostic when it blinks? I know that's a little harder, but I had an issue like this with my car. It would randomly die then drive fine. Eventually, I was able to have it die and test it on the shoulder. Ignition related issue, but same concept.