95chevyz28

Ok, so i was finally able to get the codes from my car. Whats wierd is that when i first started it, it was running rough. After a few mins, it didnt change until i just slammed the gas to the floor. Then it started running fine..... Well, the codes are 42, 23, 48, 36. Im unsure on some of them. Hopefully you guys can help.

Code 42 - PCM did not detect any est signal within 84 crankshaft revolutions..(what the hell is this?)
Code 23 - Inlet air temperature sensor signal showed an air temperature below -31° F for 60 seconds after the engine has been running for 4 minutes.(Is this because it was cold outside?)
Code 48 - There was no MAF signal when engine was on.(could this have been because i did have the maf off before and then put it back on?)
Code 36 - ECM detected less than 40 high resolution timing pulses between each low resolution pulse for 5 consecutive cycles.(Im assumming this is the opti telling me to get a new one)

Please help, i really need to get this car running well again. Also, when it was up to operating temp, if i gave it a quick jab of gas, the rpms would drop for a split second and then it would rev up. Any ideas on that? I greatly appreciate all the help. Mike

ss.slp.ls1

iTrader: (36)

All those codes mean you have a ground issue. I would check the three grounds on the coil. One should be a double wire ground, a single wire ground, and a braided wire ground strap. Make sure the ground strap is secured at the coil on one end, and the chassis on the other end.

95chevyz28

By coil, do you mean the icm? When i took it off, i dont remember seeing any ground wires. I can take another look tomorrow morning. Do you have a pic by chance?

95chevyz28

Also, could it possibly be the alternator not supplying enough voltage? Any way to test while its on the car?