jbeane

iTrader: (4)

ok, the car is a 99 z28 125k on the chassis. never had a issue with it starting in the short time I had it.

put a ly6 6.tlr in. did the 24x wheel and tsp cam etc etc.

first time starting it, it had no oil pressure. only ran for a couple seconds then shut it off.

changed the oil pump now the car wont start.

WHAT ITS DOING

turn key on and fuel pump runs for about half a sec then shuts off, security light comes on and nothing. motor will crank but not start.

have checked all grounds to the pcm, checked ign, checked fuses, and relays. (pump has hard wire kit)

also took the pcm to BLUECAT and had him delete the VATS. so it doesn't even look for the key chip.

what are we missing?? the car started just fine, before and after the swap.

christiandoy

iTrader: (1)

There is just simply not enough information here to be able to help you.

jbeane

iTrader: (4)

theres not much else that can be said.

we have checked all grounds, all fuses, all relays, had the pcm checked by a very well known east coast tuner, he dis abled the vats and security out of it.

we tested the pcm on another car and it started it fine.

fuel pump has been tested. checked everything we know to check plus everything everyone else has suggested.

what were down to is the pcm wont send signal/fire the pump, injectors or coils, and we cant find any reason why.

what else is needed ??

LS1Z28

iTrader: (18)

Did you make sure the timing chain is on right?

jbeane

iTrader: (4)

Yes. Its in time. The few times it did start it was fine.

Its something in the electronics. Timing chain wouldnt control the pcm output

Doug G

Bad cam or crank sensor ???

jbeane

iTrader: (4)

Would that stop the pcm from powering the fuel pump too?

Doug G

I wouldn't think so...but the pump in my truck will come on for a few seconds and then sounds like it shuts off with a "key on position" so maybe you're on to something ?......ignition switch/wiring ?

Just throwing ideas now.

BRUTL

iTrader: (27)

If the security light is staying on, id be inclined to follow that route. Is it staying on after the VATS delete? Possibly something went wrong with that. Really what you need to find out is what you're missing. When a car won't start, sometimes its good to go back to basics, fuel pressure, spark, injector pulse.

jbeane

iTrader: (4)

No as posted above the security light is gone after all the security and vats was disabled.

Everything worked as it should and just stopped. The pcm wont fire the inj, coils, or pump and we cant find why. The pcm works fine in another car but wont in mine.

jbeane

iTrader: (4)

checked pcm grounds again. and also swapped out the bcm and no fix.

the pcm has power, and grounds, but wont send triggers to the injectors or coils.

what else would control the pcm sending signals out???

we tried the pcm in another car and it started right up.

christiandoy

iTrader: (1)

When the car is cranking do you hear the fuel pump running?

02ls1gun

The fuel pump will run with a bad cam/crank sensor. I had the same issue. Check for any trouble codes relating to the cam/crank sensor. I was givin a crank sensor code after I had put in a new crank sensor and sure enough some of the wiring I had redone to the sensor had a bad connection. GOOD LUCK!

BRUTL

iTrader: (27)

I'm fairly certain that the pcm knows when to fire everything off based on the crank sensors input. Maybe you have bad wiring, sensor or reluctor... Hook a scan tool up and see if you're getting an engine rpm signal, which would be read from the crankshaft.