well i bent a pushrod last week and got the new ones in today. they are summit brand chromemoly stock length. the car has the lt4 hotcam kit with ported heads/intake, headers, cai and delteq. after adjusting the valves... getting each cylinder one at a time on roll over and spinning the pushrod until it stops spinning while tightning down the nut. then giving it a half a turn then locking it in place. i did that on all the cylinders and then when i hooked everything back up the car would fire and run for a second, but then it just dies. if i give it gas it will stay running for a brief second then die again. there is no chattering like the rockers are loose or anything... and i dont think the valves are too tight so i just dont know what it could be. all sensors are hooked up and the ses light is not on. so any and all help is greatly appreciated. thanks alot

daniel

 

Is the oil pressure sensor hooked up in the back of the head?

 

yea... i was making sure to pump up the lifters (stock) before i adjusted the valves. am i supposed to do that? i have never adjusted valves for this type of cam before. but yea that sucker is definatly hooked up. thanks for the thought though. are you speaking out of personal experience?

 

No, my last mistake was leaving off the VSS connector after my rebuild and when I drove the car the thing wouldn't shift and acted all wierd until I noticed no speedo action, so that was all I had left unplugged out of all the sensors.

In your case I was trying to remember if the PCM looks at the oil pressure before turning the fuel pump on after prime, but my manual is out in the garage. I would think, that even if your lifters were all out of adjustment, it would still run, although maybe badly.

I don't think it's a good idea to take the rockers so tight the pushrods won't spin. Even on new ones, I just turn the posilocks until I feel the first resistance of the lifter, then go 1/4 turn & tighten the allen, then tighten both about 1/8 turn. That is for a static adjustment, of course, and I may not be at the optimal adjustment that way, but I've never had it not work.

 

The PCM doesn't monitor oil pressure and your fuel pump primes as soon as the key is turned to on, not start.

 

just use a compression tester--that will tell you if you tightend the rockers down too far.

 

it sounds like your method of tightening the valves was incorrect. you cant tighten I/E valve cylinder on cylinder. Put the motor at #1 TDC and tighten the all the valves that are closed (I:1,2,5,7 and E:1,3,4,8), then rotate the crank one revolution and tighten the other valves that are closed (I:3,4,6,8 and E:2,5,6,7).

here is shoebox's website:
http://shbox.com/1/4th_gen_tech2.html#adjust_valves

**you really should charge people for your website shoebox!!!**

 

ummm no.... there are so many different ways to adjust the valves. i like to do mine when the cylinder is on roll over meaing that both the intake and exhaust valves are closed at the same time.

thank you all for the responses, but last night i was sittin in bed thinkin about it and i totally forgot that the throttle body is a huge vaccum source and i didnt have the intake elbow on. so i put it on and now all is great. the only thing now is that i have a high rpm miss, just gotta dig into it a bit. lol ut thanks for all the respones guys

http://www.ls1tech.com/forums/showth...89#post4956489

 

Your rockers are too tight.. almost 100% no doubt about it.

Start over following shoebox's guide. You went well past zero lash and overtightened.

Zero lash is *not equal* to "not spinning"... just a slight drag and no more up and down movement.

*edit* posted close to the same time...

Should have still run with the intake elbow off... I know mine did. I still think your rockers are too tight.

 

yeah...the elbow being on or off shouldn't have anything to do with it.

 

The engine will NOT run with the intake elbow off unless the MAF is unplugged.
Unplug the MAF if your elbow is off the Throttle body....bet that is your problem. I did this once and forgot to unplug the MAF when the elbow was off and it acted the EXACT same way !

 

I know that, but the guys on the LT1 edit list at one time thought there might be a hookin with one of the other sensors for fuel pump run during cranking. But what I meant to say to the guy is that the fuel pump circuit DOES look at opti reference signals, and if they are not present, it will not run the pump besides the 2 second blip when you first turn the key to "on". And the symptoms for that are just what he described - Seems to fire briefly but not run.

 

yea i had the maf plugged in with the elbow off. which makes sense why it wouldnt run. but thanks for all the replys guys. i really appreciate all the help, either today or tomorrow i will readjust the valves.

 

but i was wondering, could it be because the stock knock module is picking up extra noise? it didnt have this problem before i did the valves, so pretty much that is what is left. if i adjust the valves and it doesnt go away? i made sure nothing was arching and all the plugs are snug and have good connections.

btw, it starts to miss at about 4000 rpm or so. plugs are autolite 106's gapped to .050