CJohnsonZ28

So I have a 98 z28, on first start up it will miss and run horribly only when I hit the gas, idle is fine, and then it'll clear out and run ok. For quite some time now when I drive the car in hot weather and after hot restarts for awhile it will start missing and running bad and eventually lose all power when I hit the gas. It did this a few years ago and was popping some fuses.. To make a very long story short, I changed the PCM in march and it seemed to fix it til now. Also, when you plug a scan tool up to it, it will say to turn the key on and when you turn it, the scan tool shuts off and I've tried multiple ones. I checked my wiring to the connector under the dash and they're good. Also, my low coolant level sensor is always on. I'm going to try changing the coolant temp sensor but I don't think that is going to fix it. All I have left is to try and check all of the grounds in the car. Does anyone have any ideas??? I'm completely lost at this point after trying to fix this issue for years now. Any help is appreciated!!!

gagliano7

I would say you have some kind of wiring problem or a fuse blown. The scan tool problem sounds like a wiring issue. Can you hook up any tuning software?

CJohnsonZ28

I'm not able to hook anything up to it at all.. And the only fuse it blew recently was the ac/cruise when it shut off yesterday, I changed it but it didn't affect the car at all.

CJohnsonZ28

Also, the car doesn't get really hot while driving it, maybe a little over 210 til the fans cool it back down to 210 but when I turn the car off, the temp gauge goes right to the red. Idk if that helps at all but it's something else I noticed.

gagliano7

You have some kind of wiring problem. I would go over all your wiring and check all grounds. See if the ground on your od2 port is good.

CJohnsonZ28

I've gone over as much wiring as I could without ripping it apart.. I'm going to check the grounds in the next few days when I get time and let you know what I find. Any suggestions for checking the grounds behind the head?

gagliano7

Never had to check them on a Camaro. Pretty tight back there . Maybe easier to see from underneath.

CJohnsonZ28

Ok so I checked all the grounds, they're good. Replaced all the fuses and now the DLC does work and read the codes, which I have a Christmas list of codes that I'd like people to help me out with. I checked the O2 sensors and all connectors, had a decent amount of condensation and some power steering fluid in two connectors, which I cleaned and put dielectrode grease on and I'm almost sure was my problem bc now the car doesn't miss on cold or hot starts.. Here are the codes, I have access to alldata so I know what they are but can anyone help me figure out if the O2s caused the other codes to show up?
The codes are P0133, 0138, 0152, 0158, 0300, 0327, 0401, 0480, 1133, 1153. All of the codes are O2 related, either high voltage ones or insufficient switching, 0300 is engine misfire, 0327 is knock sensor circuit front, 0401 is egr system flow insufficient, and 0480 is FC relay 1 control unit.