I was about to pull the stock FPR, when I realized there was no doing it because of the fact that I had no bracket for the replacement AFPR.

So I reassembled everything. I re-attached the throttle body to the intake manifold, reattached the 90-degree elbow and MAF to the throttle body, and reattached the charge pipe to the MAF.


I started the car and it ran fine (or so I thought). It began idling VERY rough as I was going to the drive-through, and the rpms were at about 500 rpm in Drive unless I turned on the car's fans (NOT AC) I took the car up to 3k rpm and heard a whooshing sound I had not heard previously. The car basically stopped accelerating as I did this. I drove the car normally for a quarter mile after leaving the drive-thru, and tried again. Taking the car over 3k rpm and trying to sustain it caused a whooshing again, then the car 's rpms dropped precipitously and the car dipped forward a bit as if the brakes had been applied. The RPMs stayed at 200 rpm for about 30-45 seconds as I turned a corner, then the car died as the rpms dropped to 0 and the car stalled.

I tried starting the car, but it wouldn't start. It cranked, and seemed to turn over, but dies almost immediately, as though it is starved for fuel. I did this a couple times, with the same result.

That said, the FPR was never disconnected from anything. Any ideas what this could be? I got the car pushed to my house, and I will look at it again in the morning...

 

sounds like a giant air/vac leak to me, like when I forgot to tighten a t-bolt clamp behind the maf after an engine swap and my intake piping came completely off the throttle body.

 

I was sitting on the toilet seat not 20 minutes ago when the exact same thought occurred to me. I just got back indoors from checking under the hood, and, yeah... The 3-way tee to the brake booster and 90-degree elbow wasn't connected, and the damned 90-degree elbow had slipped from the TB... so the car was either getting unmetered air/starving for air/getting WAY too much air...

I haven't tried starting the car yet, but I am pretty sure we are both right. Ha! great minds...

 

Did you make sure your MAF is connected. Those are the exact symptoms when the MAF is not connected.

 

MAF was connected properly. I started her up this morning and she fired up just fine. Runs the way it did before I started work yesterday (so still showing signs of a minor air/vac leak). I made sure everything was hooked up tight.

How many psi of vacuum should I have on a boosted car at idle and throughout the rpm range in gear? I have a boost gauge attached to a tee off the fpr... and I am wondering what it should be reading.

 

I have mine on its own source

I see about -18 to -20 at idle. -22 while braking on the highway anywhere from -18 to +4 through normal throttle. If you blip the throttle it should shoot to zero pretty fast while cruizing and at partial throttle should chill around -10ish depending on your foot location.

 

Geez. Mine reads somewheres about -5 or -10 (at idle; the guage is sitting in the engine bay so I haven't gotten any readings under load/boost). What are you using as your vacuum source? I'll try to establish a baseline using your source and try to determine where I may have vacuum leaks.

 

Right now I have my boost gauge tapped on the rear of the manifold right after the TB, and I have my Greddy Pressure Sensor reading off its vac source a bit farther down the runners towards the middle coil on the rear. Both read the same. Your FPR should really mess it up all that much

 

Any pics by chance? You are tapping the manifold where? I dont see any vacuum hoses there, so are you tapping the brake booster line or something? Forgive me, I am a n00b.

Also, Matty... You have installed a Z32 MAF, right? I have one waiting to go in, but I have this fear... that I will blow the MAF and/or my ECU by wiring it wrong. I have read the wiring instructions, but of course, my wires don't match in color, and I have the J30 MAFS with extra unused wires...

 

Its right past the TB on the back side of the 00VI. Its a Vac source, not the huge vac source for the brake booster. Thats on the entire other side of the motor and should ONLY be used for the brake line.

On the Z32 (22680-30P00) ...

A (No wire) = not used
B (White) = A32 White (Signal Wire)
C (Black) = A32 Black (Ground)
D (Orange) = A32 Black (Ground)
E (Black/White) = A32 Red (Power)
F (No Wire) = not used

-matt

 

HMMM.. I am still using the stock VQ30DE IM, which would probably explain why I haven't seen what you are referring to. Not sure, but I don't think that such a vacuum source exists on that IM.


As for this, seen it and to the extent I can, have followed it. I guess it's really more a question of how confident I am with actually wiring/implementing it (I'm not!) Did you solder or splice?

 

Yes it does. There a vac source just like the one I am explaining. I went from DE IM to a MEVI to a 00VI and they all had it

I spliced. If I were to do it again, I would solder. I solder everything now.

-matt

 

The manifold vac source was all 5/8 " heater hose, rught? And boost guages normally connect to a much smaller vacuum hose, right? what did you use to bridge the two?

Running through hardware and auto parts stores turned up nada...

 

I'm getting my vacuum source for my boost gauge and other goodies near the Fuel pressor regulator. I believe the size is 3/16".

 

Vaccum line is 5/16" inch. You can get the supply from the FPR, but I like getting my boost gauge source from its own source like a different line off the IM.

-matt

 

Cool.

I have been noticing something since I relocated the gauge to the cabin, though.


The darned thing has never risen above the 1-2 psi mark under load. So even while driving about 45-50 mph and at full throttle, keeping the car at 4000+ rpm, the needle never rises above 1-2 psi. Is this normal if I am running on a 2.87" pulley?

Ideally I can get to a track where I can keep the tach near the limiter, but this is the best i can do on public roads. Still... is this normal? Where should I be seeing the 7-10 psi the V1 is capable of with that size pulley?

 

what kind of gauge is it? I'm seeing around 8 psi by 4000 wot. I had a autometer mech gauge before and it wouldn't get past the 0 and it would never zero out when i shut the car off. I called autometer up and they told me to send it in and they sent me a new one. If you are using a mech gauge make sure you don't have a vac leak and the line isn't pinched.

 

I have since moved the boost/vac guage into the cabin, and it reads the same...

Isn't this MORE than a little too low for idle vacuum?

I assume it may also explain my (seemingly) horrendously low boost levels...

I may buy a second mechanical boost gauge and try using it to test. This is downright weird...

Also.. The gauge is an AutoMeter Ultra-lite mechanical boost gauge. I would consider it suspect, but I have all the symptoms of a damned vacuum leak. My mechanic found a couple leaks, but based on the way the car is behaving, i still have some, somewhere.

Everyone is suggesting the carb-spray method of trying to find vac leaks.... but wont that stuff penetrate the vacuum hose and cause the engine note to change even if the hose has no holes?

 

Incorrect. I just checked. Vacuum line from FPR is 3/16".

 

Anyone have good pics of the valid manifold (as opposed to ported/thorttle body) vacuum lines that can be tapped for a gauge?

 

Serious ?? maybe I should change over to 3/16"

-matt