2001f4s

Thanks will keep looking and testing an keep you all updated.

Appreciate the input and assistance.

Jeff N.

+1 for the pressure test. Get a spray bottle with soapy water and squirt all the connections. You'll find it in a hurry. No simpler and faster way. That Homedepot device is sweet - have yet to see one simpler and cheaper....nice job!

toddk911

Smoke test! It is worth the money to have a shop do it. Saves a TON of time and headaches.

boerge

One question for pressure testing intakes: How can you build pressure in the system, wouldn't at least one of the exhaust valves be open, making it impossible to build pressure?

I know pressure testing works, I just don't know how, assuming above is true.

Jeff N.

I haven't had this issue really but if you do, just roll the engine over until you get to a point where there's no valve overlap. If either the intake or exhaust is closed...you are good.

schip43

So basically at the halfway point? All the pistons down in the bores?

2001f4s

I did the pressure test connecting the pressure to the J-Boot. I did not have an issue with the exhaust valves. I believe at 15PSI or so, you can still hear the leaks. But I think hooking it up to the intercooler is a better option as recommended here cuz its easier that way to hear where the leaks are.

I also used a little smoke from a lit incense to do sort of the opposite of the smoke test when combined with the pressurized intake trick.

2001f4s

SO I pulled the intake last night and found the hoses on the ISV to be loose. So added some clamps and hoped that I had found the problem. Unfortunately that was not it. The car seems to run pretty well, but I am still around 8 inHg for vacuum. Tried the soapy water approach, no luck. Tried the carb cleaner approach, no luck. I am thinking with it being about 10 inches deficient (that's what she said) it needs to be something major, and therefore should be obvious.

The only thing, is I believe the car has a cracked header. Definitely a good exhaust noise coming from the passenger side of the engine, and it sounds like an exhaust leak from inside the car. Could that have an effect on the vacuum level. I am guessing so, but any input would be great.

Getting to the point of taking it in for a smoke test. Not having much luck here.

refresh951

Have you looked at this thread:

https://rennlist.com/forums/944-turb...e-bad-bov.html

And this:

https://rennlist.com/forums/944-turb...cuum-leak.html

If you pinch the line to the BOV does vacuum reading go up significantly? He said he tee'd in between the dampner and the BOV, is this a problem? I think it might be.

2001f4s

Shawn,
First off thanks for sticking with me on this.
Those links were great, and I just ran out to the garage to see what I could come up with.
So vacuum at warm idle is actually about 9-10 inHg.
When I pinch off the BOV valve it goes up to about 14-15 inHg.
So you are right, I believe my BOV is at least part of the issue, if not all of it.

Thanks again
Scott

refresh951

Scott,

I think the issue may be the location in which you tapped in for your vacuum gauge. You might want to try tapping in on the line the goes into the FPR and see if vacuum reads correctly.

JohnKoaWood

O2 sensor doesn't really respond that quickly...

Verify your AOS and ISV are plumbed correctly, if backwards you are pressurizing your AOS, and loosing air (and vacuum) there... ISV should be plumbed to the hard pipes, AOS should be plumbed to the J Boot..

I have seen this a time or 2...

2001f4s

SO are you guys saying BOV is not the issue? Figured I'd finally found the issue.

I am pretty sure AOS is plumbed to the J-Boot. But I will trace those lines.

Scott H

I have a good Bosch DV I can part with if you find that is your issue. Has less than 5000 miles on it and it's the upgraded 110 version.

refresh951

Scott,

I did some tests on my car and I think it is a bad BOV.