Jump to content
SAU Community

Recommended Posts

I installed my blitz turbo timer with the built in boost gauge by an auto electrician and he t piece off the hose between the inlet manifold and the fuel pressure regulater.

i read off some document that it not a good idea to plumb it there. is this true and which other vacuum line can I tap into to get boost reading and where its located?

this is what the document state: do not tap into the hose which runs from the inlet manifold to the fuel pressure regulator, or the wastegate supply line. If you loose pressure in these two hoses due to crimping or the hose blowing off, you risk killing your engine.

Link to comment
https://www.sau.com.au/forums/topic/77367-tapping-into-vacuum-line-question/
Share on other sites

I installed my blitz turbo timer with the built in boost gauge by an auto electrician and he t piece off the hose between the inlet manifold and the fuel pressure regulater.

i read off some document that it not a good idea to plumb it there. is this true and which other vacuum line can I tap into to get boost reading and where its located?

this is what the document state: do not tap into the hose which runs from the inlet manifold to the fuel pressure regulator, or the wastegate supply line.  If you loose pressure in these two hoses due to crimping or the hose blowing off, you risk killing your engine.

Absolutely correct, it is not a good idea. I would like to tell you the best place to plumb a boost gauge, but you haven't old us what engine you have. So I can't.;)

PS; Why do people not fill in their profile? That way we wouldn't have to keep asking.

the best place to tap your boost meter into is the line between the inlet manifold and the fuel pressure regulator. it works in the opposite to what you have been told because at idle you are producing more vacuum than at flat chat because the throttle butterfly is closed

works like this

IDLE, low pressure(more vacuum)=low fuel pressure(less fuel)

wide open throttle,high pressure(less vacuum)=high pressure(more fuel)

once your into the positive pressure or boost it holds the pressure regulator closed by putting positive pressure behind the diaphram

if a hose were to blow off when under boost you will have a problem weather it is your pressure reg hose or your pcv valve hose

thats as simple as i can explain it, i hope it helps you out

if you are still confused PM me and ill explain it a bit clearer

the best place to tap your boost meter into is the line between the inlet manifold and the fuel pressure regulator. it works in the opposite to what you have been told because at idle you are producing more vacuum than at flat chat because the throttle butterfly is closed

works like this  

IDLE, low pressure(more vacuum)=low fuel pressure(less fuel)

wide open throttle,high pressure(less vacuum)=high pressure(more fuel)

so if you bleed pressure off the fuel pressure reg(give it less vacuum) it will actualy give you higher fuel pressure because it is effectivly sencing more load on the engine(even though there isnt)

you will still lean out from having unmetered air being added after the air flow meter(s)

thats as simple as i can explain it, i hope it helps you out

if you are still confused PM me and ill explain it a bit clearer

are you trying to say do as what the statement state

even "sydneyboy" said is not a good idea to tap it into the line between the inlet manifold and the fuel pressure regulator

Sup Godzil_R,

Some peoples don’t like to tee between the plenum and fuel reg, cus the chance of one of the connections popping off, surly a] you shouldn’t have the issue in the first place, if you secured them b] what stopped it popping off before you teed in? Two extra joins, and a slight "reservoir " effect, with all the air in the line, between gauge and tee ( assuming not digital gauge)

That said, Id use maybe the std map sensor line, or one of the many at the back of the engine... I guess even tapping your own, into the "runner crossover collector" thingo

Check and triple check all connections =PK

^^

Q for GeeTR or anyone that know da answer, if the chance it did pop off and i didn't know of it,is there any noticable sign beside looking at the gauge(as i said its a tt with the built in digital gauge and it mounted low so i can't really see it) and will there be any damage to engine?

ok i was a bit unclear

if you have a vacuum leak anywere after the throttle butterfly you will get a manifold pressure change no matter were you take your reading from

so if you have a vacuum leak in your map sensor line, this will also affect you fuel pressure regulator because manifold pressure has changed

i dont suppose you had a look at the instructions that came with your blitz products. i know its all in japonese but take a look at some of the diagrams included and look were they say it should be

i have the instructions to my boost meter right in front of me. it is also a blitz product and it has a nice little diagram of were you place the T peice suplied with the product and it is exacly were the information is telling you not to put it

there is a picture of a fuel rail with four injectors in front of it and on the end of that fuel rail there is a fuel pressure reg with a vacuum line coming off it. the vacuum line has a circle around it and there is an arrow going to a nother diagram of the T piece being put into that vacuum line

im just wondering why people would think that a company like blitz would tell them the incorrect way to set up their pruduct

it is not a fluke because this is also what i have been taught

if im wrong im keen to hear other peoples oppions

has anyone else been taught a different way

i dont suppose you had a look at the instructions that came with your blitz products. i know its all in japonese but take a look at some of the diagrams included and look were they say it should be

i have the instructions to my boost meter right in front of me. it is also a blitz product and it has a nice little diagram of were you place the T peice suplied with the product and it is exacly were the information is telling you not to put it

there is a picture of a fuel rail with four injectors in front of it and on the end of that fuel rail there is a fuel pressure reg with a vacuum line coming off it. the vacuum line has a circle around it and there is an arrow going to a nother diagram of the T piece being put into that vacuum line

im just wondering why people would think that a company like blitz would tell them the incorrect way to set up their pruduct

it is not a fluke because this is also what i have been taught

if im wrong im keen to hear other peoples oppions

has anyone else been taught a different way

the instruction doesn't have a diagram showing where to T off the vacuum line, that why im unsure

I tee'd mine into the hose that goes to the stock boost gauge..

its a little black box near the firewall on the drivers side.

is that a little black box mounted on the firewall.. and there is an electrical connection on one side and a hose on the other side of the black box?

i got a yellow hose..

should i T my bost gauge in there?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...