engine wont start

[toolman162002]

i got 94 z28 lt1 the motor wants to fire but wont. it will run if you hold your foot on the gas pedal all the way down. when i can get it to run it only stays at one rpm you cant reve it up any.i got a comp cam 306 in it new opti, msd coil, wires, plugs. i thought that my pcm is not alowing it to run properly but i talked with blackhawk and he siad that the car should run and be able to reve it up normaly. to me it acts like its misfiring or somethin i double checked my wires they are correct in all idk im stumped right now any ideas??

[Fox Slaughter]

Well, holding your foot down and EFI car is a clear flood mode. It means it stops the injectors from firing and injecting fuel.

[blacklt1firebird]

does the car have an lt4 knock module?

[meissen]

I can't remember, is the cc306 cam the really aggressive one? Is it a vented optispark or non-vented optispark? To me it sounds like the optispark was installed in the wrong alignment. I know it's possible with the 95+ vented optispark, but I'm not familiar enough with the 1993-94 non-vented gear driven optispark to know if it's possible to misalign that one as well?

Your car needs 3 things - air, fuel, and spark. Like TJ mentioned - holding the gas down when starting the car puts the car into "clear flood mode" which means the injectors aren't firing. That would mean your car has too much fuel. So that means the problem is either air or spark. I'm leaning towards spark since you changed the optispark, wires, and MSD coil (*shudders* MSD...). If the optispark can't be misaligned on the non-vented 93-94 optispark, then my next place to look would be the wires -- double and triple check the wires are in the right order. Once you do that, it's time to check the MSD coil. Since MSD coils are known to fail, here's the shbox link on how to test the coil: http://shbox.com/1/4th_gen_tech2.html#opti_test

[Fox Slaughter]

The 95-97 is vented Pin driven, can be misaligned.
The 93-94 is a non vented Spline driven. I'm pretty sure it can be misaligned too.

[meissen]

The 95-97 is vented Pin driven, can be misaligned.
The 93-94 is a non vented Spline driven. I'm pretty sure it can be misaligned too.

Yeah - I know the differences between the two, but I've never held a spline drive in my hand so I don't know for sure how it actually installs. I know the 95-97 can be misaligned... I did on Red Alert Ran like absolute dog shit, backfiring like crazy. I can't remember if I had to hold the gas pedal down when I started it or not -- I think I did, though, that's why I really think it's the optispark being in the wrong alignment. Either that or the cam was installed out of sync.

[Fox Slaughter]

Well, the spline driven might be a key spline driven. Either way he has a 95 so its a pin driven. Very easily misaligned if you aren't paying attention.

[meissen]

Yeah but his post says he has a 94 z28 LT1? And in his other thread he said he has a 94 z28 LT1? I know his profile says 95 though.

[Fox Slaughter]

Well good thing I'm not a judge. People would be wrongly imprisoned.

[my1994z28]

There is a very small key on the 93-94 splined opti,it can be installed incorrectly...To the OP,did you notice if the opti installed easily or did you "force it"?If aligned correctly it should just slide on,completely seated against the timing cover..Also if the valves are to tight the motor will not run..Take a step back and check your valve adjustment,make sure the opti is indexed correct,wires are correct..etc

[toolman162002]

yea the opti is a non vented opti and i do have a 94 i have chaned that on my profile sry. when i put the opti on it took me afew times to get it on the spline but it wasnt forced on. when i get home from work ill pull the harmonic balancer off again and double check it. and when ihad the timing chain cover of i hadthe two sprockets meeeting eah other 12 and 6 clock went by the book on that one. and ill test the msd coil to see if it is ne good. thanks for the help guys!!!!

[meissen]

One trick I've heard of is to draw a line with a sharpie on the center spinning part of the opti (on the 93-94 it'd be the central shaft before the spline, on the 95+ it'd be the wider hub) and that way you can make sure it's not spinning on you when you're installing it. When I installed my vented optispark incorrectly, I thought it went in smooth as a knife through hot butter but somehow it still managed to be in the wrong hole.

Before going through the trouble of pulling the optispark off (since you'll have to redrain the coolant and all that), check to make sure the spark wires are in the right order, the MSD coil is sending the right signals using the link in my previous post. What rockers are you using with the cam? Are they poly locks?

[98blackbeauty]

when you drain the antifreeze, remove the bottom bolts on the water pump. This will drain the fluid without hitting the Opti.