-10 in hg of vacuum after rebuild. Boost leak, or vacuum leak?

Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
Well I just rebuilt my engine have about 300mi on it so far and I'm only getting -10 in hg on my glowshift boost/vacuum gauge. I sprayed everywhere with WD40 to try and locate a vacuum leak and haven't been able to locate anything. On my AEM Uego wideband I'm getting 14.5-15.5 afr driving under normal load and idle. It of course goes lean whenever engine braking. But I cannot find any signs of a vacuum leak and its driving me crazy. Correct me if I'm wrong but isn't the normal vacuum range around -15 to -20 in hg? I've looked all over and haven't been able to find anything (including the tsrm). Any help would be greatly appreciated.
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
Thank you. So what I'm getting from that is that I either have leaking rings or worn rings. My pistons and rings are new could it be that the rings haven't seated yet?
 
IndigoMKII

IndigoMKII

New Member
May 9, 2011
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Madison, Virginia
Late Valve Timing Steady 8-18 inHG, at idle. This could be a possibility too.

Some say that if the rings haven't seated within the first 20-50 miles, they aren't going to seat.

I drove mine carefully, trying to not build any boost at all but not let the engine lug at the same time, for around 1500 miles. Been giving her hell ever since.
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
Just started the car and revved it a cpl times. Vacuum dropped to about -2 inHG then returned to -11inHG. I unhooked my IAC valve and revved it again and nothing happened just returned to idle. I adjusted the little screw on the throttle body linkage the one at the top and it wanted to die. Is this an indication of anything? Please this is driving me absolutely bat shit crazy!!
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
Wow I ask for help with a problem and get disrespected. I thought this was a site for helping ppl out with their problems not bashing them. Appreciate the helpful ppl. Yes I've checked the vacuum lines going to the vacuum/boost sensor and they are fine. I've also checked my timing and it is also fine (according to my timing marks). Would a bad wastegate actuator cause this problem because im also only hitting 5lbs of boost?
 
Suprapowaz!(2)

Suprapowaz!(2)

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Apr 10, 2006
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Suprajay;1942167 said:
Wow I ask for help with a problem and get disrespected. I thought this was a site for helping ppl out with their problems not bashing them. Appreciate the helpful ppl. Yes I've checked the vacuum lines going to the vacuum/boost sensor and they are fine. I've also checked my timing and it is also fine (according to my timing marks). Would a bad wastegate actuator cause this problem because im also only hitting 5lbs of boost?
Click to expand...

How's your timing according to a timing gun? Where is it at with E1 and Te1 jumped? What's the RPM at idle?
 
IndigoMKII

IndigoMKII

New Member
May 9, 2011
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Remove the pipe going to the throttle body, is the valve shutting all the way?

Check your CEL codes, fix any that appear.

Take off the vacuum line coming off the intake manifold closest to the fuel pressure regulator so that it will eliminate any leaks on the vacuum manifold.

Make sure your mechanical timing with 0 degree TDC is set by double checking that both cam gears point to the groove above them and the harmonic balancer points at 0.

Set your static timing with t1/e1 jumped to 10 degrees. Your car should be idling around 650 if it's a manual.


A bad waste gate will have nothing to do with the vacuum of the engine, it's not connected in any way possible.
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
Ok so i set my timing per tsrm during my rebuild. I followed the tsrm religiously during the rebuild. now i had the head resurfaced and the block decked and have a 2mm hg and i heard that this can change the timing a little. Do you guys think this will have an effect on my timing? BTW my timing set with the connectors jumped is 10 and with them not jumped its 13.

I can't check the throttle valve today due to its raining here in missouri. But I'm pretty sure it isn't because I had to adjust the little screw on the throttle linkage to open it a little in order to keep the car from dying. I know it isn't the right thing to do and it isn't a permanent fix just a temporary fix until I figure out why the car is dying with it closed.

Which vacuum line are you talking about? There are a couple in that area. If you could post a pic to clarify which one it is that would be awesome.

As far as the CEL I don't have one. Would I still have codes even without a CEL?

Now I have a 57 trim ct26 will this cause any problems with vacuum due to it moving more air? My AFR is right around 15.5.

Thanks for all the help and once the weather clears up here I will post my findings.
 
J

jake8790

Life's too short for N/A
Dec 18, 2011
395
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Oregon
It's the large 90 degree elbow vacuum line directly behind the alternator. Take it off and cap it on the intake side.
The 57 trim won't affect it.
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
Ok so I did that and it didn't change the vacuum at all. Also adjusted the screw i messed with to keep the idle up so the valve would close all the way. RPMs dropped to 500. I tested my AFM which according to the tsrm is supposed to be 2000-3000 Ohms at 68 degrees which it currently is and I got 1558. I think that might have something to do with my idle issue. Checked my TPS and ISC and they checked out fine. So I've got to start looking for a AFM. I'm beginning to wonder if this glowshift gauge isn't just a piece of crap because I'm not running lean like I have a vacuum leak and any other vacuum line I pull off doesn't seem to change the vacuum reading. Really scratching my head on this one.
 
IndigoMKII

IndigoMKII

New Member
May 9, 2011
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Madison, Virginia
Suprajay;1942303 said:
Ok so I did that and it didn't change the vacuum at all. Also adjusted the screw i messed with to keep the idle up so the valve would close all the way. RPMs dropped to 500. I tested my AFM which according to the tsrm is supposed to be 2000-3000 Ohms at 68 degrees which it currently is and I got 1558. I think that might have something to do with my idle issue. Checked my TPS and ISC and they checked out fine. So I've got to start looking for a AFM. I'm beginning to wonder if this glowshift gauge isn't just a piece of crap because I'm not running lean like I have a vacuum leak and any other vacuum line I pull off doesn't seem to change the vacuum reading. Really scratching my head on this one.
Click to expand...

Have you gone back over the intake manifold bolts and torqued them in sequence? What about the gasket on the back side of the intake manifold for the EGR valve?

WTB smoke tester..
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
I torqued all of them according to the tsrm but I can go back and do it again, couldn't hurt I guess. I have the driftmotion egr block off so there is no egr there anymore but I put the nuts back on and torqued those as if it was there so it shouldn't be leaking. Again I'll check that too. So even tho my AFM tested out of range it's ok? And if my intake was leaking wouldn't I be running lean? Just curious is all.
 
Suprajay

Suprajay

MrGoFast
Apr 11, 2011
33
0
0
Okinawa, Japan
No I don't want to take it to a mechanic. So what your saying is that it is my wastegate or are you trying to be funny? Just trying to get some help sorry if in some way shape or form I've pissed you off.
jetjock;1942320 said:
It's the waetegate! And you are lean. Have you thought about bringing the car to a mechanic?
Click to expand...
 
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