96z28_lt1

iTrader: (3)

Hey everyone i have a 1996 z28 i just finished putting back together, trouble is it won't start. The mods i have done are

new comp cam
le2 heads
longtubes
roller rockers
new opti, wires and plugs
58mm pp throttle body
ported intake
got rid of egr, air, evap, smog

anyways car has fuel i replaced fuel pump and were getting fuel, water pump was also replaced, i did troubleshooting procedure for spark everything checks out, i have spark all the way to the end of the coil wire. pulled off opti took it apart tested the cap coil connectors and have continuity, the rotor does not however, some genius painted the rotor tip so i put the old rotor in and gave it a whirl still nothing all i get is engine turns but doesn't really turn and rpms maybe 100rpms give it full throttle while cranking it turns to about 400 rpms and has small backfire out of the intake... i just have no idea what it could be anymore wasn't sure if anyone else knew?

any help is appreciated

DisasterFormula

iTrader: (1)

Sounds like the timing for the opti is off. Did you put it back in right? It's really easy to get the cam gear dowel pin in one of the indentations for the bolts. And are the plug wires run correctly?

tt383lt1

iTrader: (3)

not to be mean but did you put the came in right? do you get spark at the plugs now that you did the opti again?

96z28_lt1

iTrader: (3)

still no spark at the plugs, installed opti numerous times even took cap off and hand turned crank make sure there was no lag, cam was installed i followed shbox procedure lined the gears up at 12 and 6 spark goes from the coil just not recieving anything on the other side.... even after using my old cap and rotor

DisasterFormula

iTrader: (1)

Check resistance on your plug wires.

96z28_lt1

iTrader: (3)

hey guys i got it start, but it only starts under throttle and then dies.... its getting spark now i accidentally overtighted my roller rockers...i know i'm pretty stupid but tis my first build so no i know, but as state i can get it to start when im on the throttle as soon as i let off it dies and now it only starts then dies real quick

DisasterFormula

iTrader: (1)

Did you tune it?

sandman2100

iTrader: (8)

Check for vacuum leaks. Loose intake clamps after the maf to the TB, Intake manifold etc.

Any Codes?

96z28_lt1

iTrader: (3)

i went to check for codes, but my obd2 scanner will not work anymore on the car it works on my daily driven impala though, its not tuned yet was hoping to get it running then to the dyno this weekend but i can't even get the thing going, i was looking for vaccuum leaks nothing noticableall holes have been blocked were the evap is no longer and smog pump hole on the cold air intake has been blocked off also

out of ideas at this point, could throttle position sensor casue this like i said it only cranks up when i give it throttle starts up to about 500 600 rpms then dies

96z28_lt1

iTrader: (3)

by the way your trans am looks nice what color green is that?

96z28_lt1

iTrader: (3)

anyone have any insight for me?

License2Ill

iTrader: (1)

Loosen up all the rockers then adjust while the engine is on using the no more clacking +1/4 turn more routine. But that would be in the event it stays on of course.
They sell these rocker arm tip covers so the oil doesnt squirt at you...but otherwise you can lay down a wet towel over the headers as well for a little while.

Did you happen to ratchet crank the whole engine after you aligned to the 12 and 6 clock postion once over? This is important to do sometimes just to confirm the chain doesn't end up 1 tooth off after you take off the slack by spinning it over once.

Get a hold of another ICM altho u have spark and it tends to go out and not give spark....there are some rare instances it just acts up and acts this way.

You could be off by a tooth on the cam or you could be off 180 on the Opti install....I dont recall if that's possible as I have not done an opti in awhile...but it was possible on HEI....180 degrees off would mean you werent at proper TDC. Anyway I think the dowel pin might prevent this.....so your problem may just be the rocker arms too tight still.

96z28_lt1

iTrader: (3)

when i did the timing chain i lined it up and there was no slack on the chain engines been rotated a few times, if its a tooth off that might be the case i guess, but the icm i took to autozone and it tested fine they tested it several times to allow it to get hot also, the rocker arms should be to tight still but i guess i can always just take a look at them again, i just figured it'd have something to do with the tps or iac since its a new throttle body i mean i know it wont run right because its not tuned but it should still start and idle right?

License2Ill

iTrader: (1)

Loosen them all up.

Autozone icm test is worth fukkel. best is to test w/ a known working one.

yes it should start without tune unless u maybe went with a gargantuan solid roller....but even then.......

96z28_lt1

iTrader: (3)

no its the comp cams xfi280, i unplugged the iac valve and started it under throttle it ran for about a minute at 500-600rpms still under full throttle... i also swapped out traction control throttle cable and such witha non traction control throttle cable just incase that would mess with anything i don't think it would though

96z28_lt1

iTrader: (3)

also my tps reading with throttle body untouched like it would be at idle is .8 which is higher then the .67 its suppose to be

96z28_lt1

iTrader: (3)

http://www.youtube.com/watch?v=Y6GCiZXTgIo
the start is no throttle then i give it full throttle like a s3cond before it starts and then the second time is just full throttle

96z28_lt1

iTrader: (3)

anyone? I don't think its the lifter because yesterday it wouldn't idle but would freely rev before i put waterpump and everything else back on, it was after i kept it revved about 2000 2500 for a few seconds that i let off the throttle and it died and this started happening think it could be fuel pressure regulator i primed the pump and pushed in the needle and got nothing

Fastredz28

Check the spark plugs see how they look.
Then you'll be able to tell if it has something to do with fuel.

96z28_lt1

iTrader: (3)

well i know i need to change the oil i checked it today and it smells like fuel but i believe thats from before it was starting when it wasn't igniting because of the compression but i'll pull a plug what am i looking for excessive fuel i forgot to mention i put bigger injectors on the car then stock also