z28rssscamaro

ok before I start here let me list out the mod and what I have done
1993 z28 lt1
58mm TB
gm847 cam
longtubes
heated o2
slp cold air intake
tune
24lb injectors

Im having a problem with the car cutting out and not running right at less then WOT. The car runs great for about 30min+ of driving and then the problem starts up. if you kill the car and let in sit for a min or so it runs fine again for a while. I cammed it about three weeks ago and it was running fine until a few days ago. I have replaced both 02s,temp sensor in the waterpump, checked the plugs and wires and now ive looked at the computer data with my laptop and MAP is fine and reads ok TPS reads fine but the 02 sensors read weird they keep goin to 30.00 mv and the cars cuts out kill it the read ok and then all the sudden its back at it again it will even cut out with both 02s unplugged and the is the seconds set of o2s

any help would be much appreciated

96z28_lt1

iTrader: (3)

check your fuel pressure, stop just replacing o2s. Check over your spark plugs, is the icm spaced away from the heads, its been known that sometimes when they got hot they cause problems.

z28rssscamaro

I just checked the fuel psi and it was 42 not running and 48 or so running with the vac line off seems ok to me The ICM is spaced away from the head

96z28_lt1

iTrader: (3)

so you can rule out the fuel, id check over your ignition components, wires, spark plugs, icm/coil

pboxfun

iTrader: (2)

Check ICM and Coil! Is there a check engine light?

z28rssscamaro

ok Ive tried another coil and ICM from my other z28 and still doing it

96z28_lt1

iTrader: (3)

id go over your plugs again, also try just disconnecting the battery, i know it seems like a long shot but simple things first before spending a bunch of money, my car had a misfire and such wasn't sure what it was, all i replaced was one o2 sensor and disconnected the battery for 30 mins and its good as new now.

z28rssscamaro

ok ill give it a shot ive got new plugs to put in tonight and then we will see what happens

96z28_lt1

iTrader: (3)

any new news? Also might want to check fuel pressure while driving as well if that didn't solve anything

z28rssscamaro

ive looked at the fuel psi while driving and it stay where it should be. i had to replace my alt last night. the bearings in the alt have been making noise for a long time. now i hear some exhaust leaks in the headers. im going to fix that then i will plug my pass side o2 back in. ive keep it in open loop lately because is ran so bad in close loop. ill post an update tomorrow .....hopefully this fixes the problem

z28rssscamaro

ok leaks fixed and it still does it idk what to try next im goin to check the computer with my laptop..... im losing my mind on this car