billzair

Heres what I got....96 Z28(bought it new)automatic, 5.7 LT-1

heres the problem...Last year, It would take a good 10 seconds of cranking to get it started. Once started it ran fine. If you shut it off for less than about 1/2 hour, and went to start it , it would fire back up right away. If it was longer than that it would take another 10 seconds of cranking.
Right before I parked it for the winter, the motor would die sometimes, but start right back up, and I was gettin some good vibration as well.I parked it for the winter, and was gonna deal with it in the spring(now)

Sooo, I go to pull it out a couple weeks ago and it cranks and cranks and wont start.So I put a new fuel pump in......still wont start..I have good fuel pressure at the rails.When trying to start it it will sometimes backfire out the exzaust or ill get a "huff" out the intake!! I love thowing money at problems.. so... I put in a new accel optispark....still wont start. Then I put in a new coil..."just incase"... still wont start. I do have spark at the plugs so I think maybe its the injectors...so for ***** and grins I have my brother crank the car while I use a little starting fluid....nothing! How is that possible?I have air..
I have spark.... And i have fuel. If it were to start with the starting fluid than I know the problem would be fuel related(injectors, etc) but I am really at a loss here......Any one have a idea?

Formula350

iTrader: (3)

90% of us stay clear of Accel and there's been cases of DOA Optis with them. Pull the easiest plug and ground it on some metal, and crank, see if there's any spark.

COULD be the ICM mounted on the head.

stfuad

Before you start throwing any more money at the problem buy a DVOM. May be a crank/cam sensor or the PCM or the ICM only testing will find out.

Formula350

iTrader: (3)

Good call on the Crank sensor (cam is in the Opti), forgot 96/97 have that.

LM97Z

iTrader: (4)

I have the same issue with my 97, for the most part, its a hard start situation, once running, its fine, i'm really leaning towards the crank sensor being the problem.

robsquikz28

iTrader: (246)

crank sensor........ its behind the crank pulley under the car u can see it easily.

SincalT/A

iTrader: (16)

Crank sensor only refrences missfires for OBD2 diagnostics.It controls nothing.Get it on a scan tool and read some of the sensors then report back.I.e coolant temp.maf.iat.O2s.
What plugs/gap and wires you running.

SincalT/A

iTrader: (16)

Possible corrosion problem somewhere maybe at the icm.I say this because it has got progressivly worse.Check ground straps also.

94z28M6

iTrader: (2)

Mine was the PCM, the signal that goes to the FP that tells it to run during start up was not working. I replaced the PCM with one I had laying around and worked fine.

billzair

I scanned the car today and it says the cam is 60 degress off from the crank.....is this possible? why woul this be?
thanks!

TXFORMULA

it might have been the opti. your opti is keyed on the backside. when you installed the new one did you make sure it went on right? the opti should sit flush BEFORE you put a screw in it. if you had to put screws in it to flush it up then its on wrong.