bodenman

I have an ls vtec fresh build just put in
I've gone through the timing and everything is good I checked spark on all plugs and there all good strong white spark. The injectors are all working . I'm stumped I did a compression test cylinders 1 2 & 3 the ones not firing are giving a cold reading of 160psi the cylindis r that fires gave 210psi not sure if this is a valve issue. When I pulled the plugs they were wet with fuel the one from cylinder 4 is black like it's running rich.
I have only a cel 21 for my vtec not wired up yet i turned vtec off at the ecu

b18a1 block
b18c1 head
p72 s300 ecu

carlos8

If you have strong spark and fuel but a weak compression on this 3 cylinders.

Did you lash the valves after build the engine?

Perform a leak down test. to see the results in this cylinders.

Is the car TUNED?

TomCat39

You can do a leak down test to rule out valve issues, or verify them for that matter.

bodenman

it isn't tuned I have an ls vtec basemap it should at least start the engine I think it is getting too much fuel and ignition timing is off I couldn't find my leak down tester so im gonna go buy another one tomorrow

if that comes out ok then im gonna remove some fuel like minus 10% from fuel trim and try moving the distributer around

bodenman

with the 3 plugs that aren't firing being wet when I pulled them but I have solid spark and the one that does fire being black that's what I was thinking anyway

also it does pop and sputter when cranking leaning towards ignition timing being wrong

TripleLude

Spark plug wires in the right order for your distributor?

lol just watch and see...

tony_2018

I don't think the tune has anything to do with the cylinder pressure. I vote leakdown test as well and also do a valve lash adjustment.

tony_2018

The title threw me off because there is no way it can only fire in cylinder 4 and not the rest.

bodenman

the problem was timing the timing belt cover wasn't on right and is deformed so the timing belt was set a notch off I found true top dead center with a dial indicator and marked the cover and re did my timing and starts right up thought I would share