Idleing really low bad vac.( 10, 7,5 hg)

[2GEEZEY]

Im getting really bad vac on my car. I have a autometer phantom 2 boost gauge so its accurate, but my car idles like crap( below 700) when i first start it. it feels like its going to die.

I have no idea whats going on here.

 

[RedTurboEclipse]

Cams? Boost leak test?

 

[BLINKY619]

def. boost leak test... and or vacuum leak..!!!

 

[2GEEZEY]

ill check again, i had all of my boost leaks fixed by midwest for the ones i couldnt find. Im redoing my boost gauge to a new spot, maybe there was a kink in the line. I have my boost gauge hooked up to the IM that is tee'd off with my afpr.

 

[guitarhero14]

My money is on that your timing belt jumped a tooth.

 

[Codester]

I agree with the timing theory. Check your timing.

 

[dsmdeliveryboy]

Are you running the stock throttle body etc still? Does it just do it till the car is warmed up?

 

[2GEEZEY]

yeah thats what i was thinking also. Sorry bur how can i check the timing? manually roatate the crank?

dsmdeliveryboy, yeah im still on the stock tb and intake mani.

 

[dsmdeliveryboy]

Have you tried messing with your BISS? Is it missing the rubber cap that goes over it?

 

[2GEEZEY]

yeah i loosened it up a bit it was sitting at 11 -12 ish, but the gauge needle was shaking. and yes there is no cap over the BISS screw.

 

[guitarhero14]

yeah thats what i was thinking also. Sorry bur how can i check the timing? manually roatate the crank?

dsmdeliveryboy, yeah im still on the stock tb and intake mani.

You need to pull your timing belt covers and line up the timing marks on the crank, oil pump and cam gears to see if its set correctly. If you need more detail here is a link:

Timing Belt VFAQ

I had this exact same issue and this was the cause.

 

[2GEEZEY]

how am i supposed to line up the oil pump and crank? should i just go by the marks on the cam gears?

 

[FUNWHEELDRIVE]

how am i supposed to line up the oil pump and crank? should i just go by the marks on the cam gears?

You keep turning the crank. It will turn a maximum of 6 times before they line up. And if its close to lining up.... but doesnt line up perfectly... than it jumped.

 

[rich3389]

yeah i loosened it up a bit it was sitting at 11 -12 ish, but the gauge needle was shaking. and yes there is no cap over the BISS screw.

If the needle is shaking that usually means an intake valve is leaking.

 

[RipperXX]

yeah i loosened it up a bit it was sitting at 11 -12 ish, but the gauge needle was shaking. and yes there is no cap over the BISS screw.

If you have a hayness manual or FSM. You can look under the trouble shooting section and find this symptom. Theres a few things that can cause this to happen. Like a damaged valve etc. OR your timing being off. Which is what I am 95% sure it is. ESPECIALLY if it was out of the blue (out of no where).



*EDIT* Darn it Rich you beat me to it!

 

[2GEEZEY]

its been like this for a while, it didnt just happen today. i can check the timing, if it is off how do i fix it?

 

[guitarhero14]

its been like this for a while, it didnt just happen today. i can check the timing, if it is off how do i fix it?

Pull the timing belt and realign everything. Basically doing a timing belt replacement.

 

[2GEEZEY]

alright will do! thanks for all the help, i do appreciate it. It has to be the timing because i turned up my idle just a tiny bit and im still getting a shaky needle on my boost gauge and its only around 10-12ish hg of vac.

 

[guitarhero14]

alright will do! thanks for all the help, i do appreciate it. It has to be the timing because i turned up my idle just a tiny bit and im still getting a shaky needle on my boost gauge and its only around 10-12ish hg of vac.

If you are doing it yourself feel free to PM me with any questions you have

 

[2GEEZEY]

alright will do, im going to look at it today

 

[RipperXX]

If your going to pull the T-belt to fix this (assuming when you check the timing is off) then for the love of god replace any worn items. Like the belt (since it's not a reusable item) and any pulley's, auto tensioner etc that are due for replacement or worn.

If you just pull it and re-align it, your playing Russian roulette imo, because next time you might not end up so lucky. You might have to replace all 16 valves next time.

 

[turboglenn]

^ nah, you usually only bend 10 for some reason

j/k but 10 is what i've always seen and you don't even want that so take the advice and get a new tensioner and belt (only skip the tensioner if YOU replaced it within the last 20-30k yourself, don't trake anyone elses word on it because most places skip this when doing t-belt jobs and half the idiots working in the garages theese days have no idea you compress them SLOW (like 1/8th turn at a time ) and they crank them down fast ruining the tensioner's hydraulic assembly if not breaking the tensioner rod it's self

 

[2GEEZEY]

im just going to take it to midwest and have them do a timing belt, better to be safe then sorry. the timing belt looks new, but idc i dont want to mess anything up.