ka-t vac issues

[alpalwal]

Alright, so I got my car running.... 240sx ka-t. It's the s14 motor in a s13.

It runs, but it runs very poorly. It only pulls about 10" of vacuum at idle and it should pull about 20.

then.... lets say you're in 3rd at 4000 rpms and you let off the gas... normally, the vac gauge would go way down.... pinned at the bottom basically. For me, it still just stays at about 10.

I've checked for leaks and there arent' really any. there are a couple pinholes, but nothing that would screw me this bad.

I was talking to my auto teacher and he said that if my timing is ****ed, that can be another cause.

I put s13 cams in the s14 motor. I think that they are just the intake and exhaust from the s13.. but im not totally totally positive. Is there any timing changes i need to do from s14 to 13?

I know my distributor timing is on besides being retarded 5 ish degrees for 10lbs of boost.

therefore........ if my timing is on the right teeth, and the distributor isn't off, where is my vac?

[Ligouri Rd]

A leak is a leak, pin-hole or not fix em first. Where is the IAC hose, and EGR hose hooked up to (large and small vacume lines near the throttle body, respectively?) Iac should be post-turbo but EGR should be pre-turbo.

[DammitBobby]

I am running 95 engine with 91 cams in a S13 and vacuum is around 19. Timing is the same. The only major difference between the engines Valve Cover, valve cover bolts, upper timing chain cover and intake manifold. I have 95 upper manifold and 91 lower manifold. You have a leak somewhere. Check with a boost leak tester, you will be suprised at the leaks you will find with it.

[alpalwal]

i have checked with a leak tester.

[DammitBobby]

If you have tested for vacuum leaks then you need to do a compression test. You could have a bent valve or broken ring lands. Somewhere you are losing vacuum.

[Florida240sx]

I used a 2" pvc cap and clamped in on my turbo IC piping. Hada hole drille din it and pumped up my system. It holds up to like 45 psi which is where the pvc cap shot off the coupling and almost got my friend lol... Fix all your leaks. Mine was a 3/8 hose that is in between the mani's beside the iacv.....