When you turn the key on does your little security light stay lit

 

I think so. can't fully remember


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Well if so you may have to take it to the dealer and have them reset the security system ive heard of it a few times before

 

Or call them and ask for the reset procedures

 

dude, your car is never gonna start with 30 psi of compression!
why hasn't anyone noticed this.
three things are need to run an engine.
spark, fuel, compression.
the reason you feel like the engine turns over to easily is because no compression is being built!
on an Acura I have, I bought a used engine, I put it in, hooked it all up as it didn't start.
I checked for fuel, had it, checked for spark, had it. check compression, had like 60 psi!
put new rings in, got 120 psi and it started up
I think the minimum psi an engine can start with is 80-90 psi.

if you didn't assemble the short block, then probably the person who did, did not assemble it correctly.
I've never taken apart an infiniti engine, but I'm sure they have adjustable valve lash, make sure that is within spec, if not te valves won't hold compression and it won't start.
no offense to anyone, but your "good mechanic" probably isn't good if he saw you got 30 psi and can't come up with a reason why.

either the piston rings were improperly placed or are bad, the valve lash is horribly misadjisted, or the valves are my seating correctly on the Vlave seat.

do a compression test on all the cylinder before you take it to an expert an let us know what you get.

Hope this helps man!

 

ok cool appreciate the info. like I have said I have done all the reassembling of this motor besides the short block. the machine shop did that. my buddy keeps telling me the timing is off and that's why there's no compression. kinda hard to believe when the timing was redone by the fsm and had two others verify before reassembling the rest.


what do you mean by the valve lash? I have a feeling the short block wasn't done right cause I put in brand new weiseco pistons and rings. I greatly appreciate the info.


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valve lash is the gap between the rocker arms that push the valves down and the cams.
if the gap is too big, the cams will barely touch the rocker arm and the valve won't open or close much and you won't have compression. if the gap is too tight, the valves will never fully close and no compression will be made.

you assembled everything but the short block?
did you get new valves? or did you do anything to the heads?
did you resurface the heads? did you get new head gaskets?
did you properly torque down the head bolts in their sequence?
and did you torque them down to the right ft/lbs?
do a compression test on every cylinders man. trust me.
at this point with what I've read, I'm 98% sure it's a compression problem.
if timing was off, valves would be hitting pistons and things would be bending and breaking.

the short block may have been assembled wrong as well.
possibly the shop who did this, got the wrong ring gap specs and made the ring gap to big.
also ring gaps must be in a certain arrangement with eachother to hold compression.

.005" doesn't seem like a lot right? but when it comes to engines, .005" decides wether you'll have compression or not. on an Acura I bought as an investment, I bought cheap rings and the gap was .017". that gap gave me about 30 psi compression.
so I got name brand rings, ring gap was like .013", it gave me 120 psi compression.
see how critical .004" was?

best option now is the compression test.

another test to help identify where air is escaping is this test.
you'll need an air compressor. screw in the compression tester hose in the cylinder, remove the gauge, and pop on the air compressor hose, this has to be done while the cylinder is in combustion position to ensure valves are closed.
once you hook up the air hose, listen closely to see if you hear air escaping,
if you hear air/feel on the intake, you have bad Intake valves.
if you hear/feel air on the exhaust side, bad exhaust valves.
if you hear/feel air from the bottom of the oil pan, bad piston rings.

^sorry that's a bunch of stuff. but hope it helps. lol

 

with these motors we don't use rocker arms. the cam lope sits on a cap that sits on top of the valve spring. valves are stop and same with the heads


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oh okay. I didn't know that. but I am doi g some research on this,
I guess on these engines, you dot adjust valve lash like on other cars where you turn a screw to change rocker arm height.
according to this thread, the caps wear down and you have to replace the caps if they don't fall with in spec. sounds like a pain

did you get new cams or valves?
try to measure the clearance between the cap on the valve and the opposite side of the cam lobe.

 

no stock cams and valves


Posted from G35driver.com App for Android

 

did you resurface the heads and get new head gaskets?

 

and the car worked fine before this right?

 

If you're not building compression, its rings or valves. You said you re-did the timing, did you just take everything off or did you check to see if it was off first? If it was off, you could have bent some valves the first time you tried cranking it. Do a compression AND a leakdown test (the test JDMswag described above), that will point you in the proper direction.

This is of course assuming you used new head gaskets, which I hope to god you did lol.

You can also take off the valve covers and make sure timing is visually good. Stick a long screwdriver in the spark plug hole so you can tell what the piston is doing and actually watch the 4 stages the motor goes through to run. The piston should travel down with the intake valves opened, travel up with all valves closed, travel down with all valves closed, an travel back up with the exhaust valves open.

 

^hopefully he didn't bend some valves and it's just some piston ring issue, this way the shop is held responsible and he doesn't have to pay more money out of his own pocket.

 

Yea would suck for him either way though, to spend the time and money to have to pull it back out.

Once you compression test the cylinders, put a teaspoon of oil in any of the low cylinders and see if it starts. Thats an old trick I learned to tell if the rings were the culprit without doing a leakdown test. It wont run for long, probably just sputter and try to start but it will give you another clue.