Ziggyrz07

1997 z28 t56

Had 98k on my first motor and she started to miss bad so I replaced plugs and wires a week later I through a rod.

Got 94 vett motor swapped cam and timing gears and intake dropped motor in car with new option new coil and new icm. My problem is I'm having the exact same hesitation and miss with no power at all and I'm afraid this new block is going end up with a snapped rod too.

Anyone have and ideas where to check next? Possible PCM or even the cam?

Injuneer

Scan it for codes, check the fuel pressure. The 97 PCM detects misfires, and keeps a record of which cylinders are misfiring. An OBD-II scanner with GM Enhanced Parameters can access that data.

I doubt it threw a rod because of a misfire.

Ziggyrz07

I'm pretty much under the impression that it was detonation that did it.

I have ran for codes I have 16 of them

Fpr is brand new and all I smell all the time is fuel I'm getting 14mpg on the hwy.

Codes I'm getting are 3 for tps but when I unplug it runs worse but I might dig out the 20$ tomorrow just to test it out. I got 4 or 5 codes for the missing smog pump bs. I got one unplugged rear 02 sensor that's throwing two codes. After cleaning up new motor and puttig old timing cover back on I think I some how damaged CPS which is throwing two more codes for that. Then I have another two codes cause some *** clown removed the check engine bulb. On morning ill replacs CPS and TPS and see which cylinders its more prominent on.

I am leaning towards a worn out cam shaft though honesty, car only has power under extreme load and even then it's still gutless.


Prior to new engine swap I had identically problems. But I had smog pump there and 02 sensor there and I wasn't throwing codes for CPS or TPS just random missfire codes.

Everything ignition wise has been replaces only thing original under hood are sensors, heads, intake, cam, and PCM

Injuneer

Most of those codes (CKP, after-cat O2, AIR pump, missing SES light) don't affect the way the engine runs, and won't cause a misfire. If you have a code for the CKP (crank position sensor) you aren't going to be able to pull misfire counts. The CKP is only there to check for misfires.

You can check the TPS with a volt meter.... you don't need to replace it to test it.

Ziggyrz07

well yanked TPS off today and well needless to say there where bugs and crap inside of it so i replaced it anyway. im going to pull throttle body off and clean it today, because the throttle keeps sticking around 1500-2k and the car can basically drive itself down the road. i ordered a new CPS so i can find out if im missing directly on a certain cylinder or if its random or whatever.

basically i have 0 power what so ever, if i raced a honda civic i would probably get stomped. and the whole time i can smell fuel while im driving, i got 160 miles exactly on a full tank of gas.

Ziggyrz07

now that i think about it... when i took apart old block i had a lifter so stuck in block i had to pound it out... so i think cam would be shot...

Ziggyrz07

Just a update. Original motor optispark was shot. While pulling accessories off to check cam I found problem with new motor. Three spark plug wires where severed from serpentine belt.

Ziggyrz07

Another update.

Shortly after I blew this engine also. The problem ended up being a stuck open injector.