boost gauge is hooked up...not working...

[va240dude]

I've been reading conflicting reports on where to T my boost gauge...some say the BOV line off the TB, some say from wastegate to charge pipe vacuum line, and some say from the fuel pressure regulator line. Well, I went with the last option and my boost gauge isn't working at all, connections,etc are good no leaks. Can anyone give me a direct answer ? Seems to me it would be to T it off the wastgate signal since that should be accurate, but this is my first swap. Thanks for any help.

[240life]

Were you driving the car or revving the engine under no load, you will only see boost pressure under driving conditions...a T off of the fpr line is the correct way according to heavy throttle and it works for me too.

[va240dude]

I'm confused because there is vacuum on that line, but it is sucking air is that what it is supposed to do?....As soon as I manually blow air in, the boost gauge moves. I'm wondering if I should run it directly from the bottom nipple.

[the converted]

All of those should work just fine. If your gague can shows vaccum then your going to want to go to the bov or fpr lines, if not it dosen't matter.

[va240dude]

yeah i've heard its not good to T off your BOV line, I want the most accurate reading...so should i T off the wastegate signal line?

[the converted]

Most acurate is going to be the fpr or the bov, because it is going to show you what is actually going on in the manifold.

[va240dude]

Yeah I have it hooked up to the FPR so I don't understand why its not even reading anything under boost while driving...

[the converted]

Did you pinch the line?

[va240dude]

the FPR line? no...I can post pics if necessary.

[the converted]

If you take the hose off the vac gauge when the engine is running can you hear it sucking down the hose?

[va240dude]

yes

[the converted]

Then it sounds like you have a bad gauge.

[va240dude]

but if I blow into the line it works

[mi300zx]

I am looking for the vacuum routing for the boost gauge on my 84 300zx, as, I do not think my gauge is working either. Does any one, know where I can find this information? I'd greatly appreciate it.

[Justin35ll]

Should be set up like this. Vacuum line running from fpr to intake manifold. Cut that line in the middle add a T connecter and run the gauge off that T. If that's how you have it set up the it should be working

Does your car actaully create boost? Do you hear the BOV/ turbo spool? Does the gauge read any vacuum? Car would not run if you're not making vacuum.

Oh yeah and a sucking feeling is vacuum boost is a pushing pressure. so if you unplug it and feel sucking that's good.If the car is running normally then your gauge is probably broken or something because that's your only possibilities

[va240dude]

Thanks for your help, I'm pretty sure I'm not making any boost, everything is hooked up correctly. I think the MAF is bad because I can't get above 2-3k RPMs when everything shuts down. Am I able to get any boost at 2k RPMS if the MAF is bad? If that's not it, I have a serious boost leak somewhere, just can't find one. Any ideas how to check for boost leaks? I can't visibly see any leaks, but it has to be somewhere? Any advice would be great....

[Justin35ll]

You can check for leaks using compressed air and run it through your system. I think you have to block off the idle air control valve and possibly something else. Maybe someone else will chime in and help you out better with this

[va240dude]

Ok I'm wondering if my wastegate line is hooked up correctly...here's how I have it set up now. Is this possibly why I can't get above 3k rpms, and I have no boost signal on my boost gauge?



I'm reading conflicting reports that say it should go off the coldpipe, or T off the BOV line (even though Heavy Throttle says the TB line goes DIRECTLY to the BOV). What should I do?

[the converted]

Your boost gauge is not the problem, your maf probably is. Do you have anything else done to your car that might require tuning?

[va240dude]

Your boost gauge is not the problem, your maf probably is. Do you have anything else done to your car that might require tuning?

I thought the MAF was too, but I swapped it with a friends working and it works fine....nothing else on my car that would require tuning....I also had the battery and alternator tested and they are working fine...I'm going to perform a more comprehensive boost leak test tonight hopefully....but the leak would have to be pretty big for it to not go over 3k rpms right?

[the converted]

Yeah but looking at the wiring issues that you were having in your other thread, there's still got to be more going on. Triple check all your grounds, check for codes again and see if anything happens.

[va240dude]

thanks, i will check all the wiring again...do the MAF wires (3 of them) need to be in any type of heat protected wrap or tubing?

[s13-t]

my set up: on the throttle body, little nipple goes to the fpr. big nipple goes to bov+ boost gauge. bottom nipple is capped off. wastgate has its own line tapped into the hotpipe