R34 Factory Boost Guage Fault

[Klymax]

Hi Guys,

After much searching myself regarding the "factory boost gauge failing" topic I noticed there's no pictures for those of us who aren't as familiar with every little modules on our cars as some others are.

If you have a Factory boost gauge and it either doesn't work at all or only works at certain times. ( I found myself mine only worked during cold times of the day)

I've found a simple check to determine wether you need to replace your boost sender unit or not.

as stated in many posts I've read there is a boost sensor basically in the middle of your engine bay along the firewall edge above your motor. I feel many are checking this and its lines instead of the unit that controls the actual gauge.

now for the life of me i cannot find to quote the particular post I was hoping to by the gentleman who rectified his sons gauge problem from finding a dry solder join.

If you have access and are confident in using a soldering iron you may not need to read much further.

For those who dont and aren't let me explain a way to solve your mystery.

if you open the boost sender unit between your panel and brake master cylinder you will notice 3 larger solder joints. If you unscrew the 3 screw's holding the inner PCB board.

Raise gently the opposite side of the board as the connector joins are quite hard to lift through the plastic housing. you may de solder these 3 large joints and re solder them properly.

If you aren't confident in soldering you may very gently left the board evenly as so the 3 connection pins pull through the board. they may bend in the direction you pulled them.

now align the 3 connection prongs and re seat the board being careful not to get any dirt inside the. once these are back through they should be sticking out the top by 2mm or so. you can give them a slight bend onto the solder to provide enough connection to test with.

restart your car and check the gauge is working. If it is not after resoldering you may require a new unit. if you chose the non solder path you could be in the same boat however make sure the solder joins are still quite nice and the tips are definatly making contact to them.

I apologise for the quite long write up for such a small task and do stress the non solder option is not a fix, instead it is a mend to test your sender unit is functioning or requires replacement.

the picture quality isnt too great but should be enough to see whilst reading the tut.

shown here inside the red circles are the 3 joints in question.

Hope this helps

-Jayme

[08yannch]

you should probs check that it is all plugged in too

that was my problem and because the gage wasn't working when i got my car i never bothered to fix it

i see this topic and i set out to fix the problem i got out all of the tools and then when i had a close look its not plugged in

hahaha lol lol lol lol

2 sec fix lol

[iwanta34gtr]

Hi I have this problem and have located the boost sensor but how do u get the lid off it? I just want 2 be sure and dont want to crack or break it.

[RusH_]

Hi guys,

I'm digging up an old thread for a very good reason.

I've had this very issue with the R34 boost gauge dropping out for nearly 3 years, i finally decided i would muck with the boost sender unit and if i broke it i'd need to buy a new one anyway!

So basically as Jamie has stated above, i am very pleased to confirm that if you open up the boost sender unit and simply re-heat the 3 large solder joints shown in the picture in the first post, heat them so they become soft and liquid-ish and then allow them to re-set again (takes 2 seconds), do this to all 3 of the large solder joints and the simply re-assemble the boost sender unit, and go for a drive, your gauge will infact work (read: 'should')

After going out for a 10 min drive, i am super pleased to say that the gauge has not missed a beat, i'll be monitoring it very closely over the next week, but i am highly confident that this has solved the issue.

So if you have this issue, grab yourself a $15 soldering iron fron Bunnings and simply follow the above steps and enjoy the result that is a working boost gauge in your R34!

[iwanta34gtr]

Good work, it should stay working. I did mine too a few months ago and it is still going perfect. Thanks again Jamie.

[RusH_]

Mine is too, still working perfectly since i posted about 3 weeks ago, very pleased

[fastjetjockey]

Working, or working accurately?

[jrm]

The sensor itself - from my experience - is actually reasonably accurate. The gauge itself is where the problem is - it really doesn't have the granularity in it's markings to be much use beyond 'low boost', 'normal boost' and 'wtf-someething-broke boost'.

After fitting an R34 GTR MFD, this uses the exact same boost sensor, and you actually get much more usable (and useful) boost readings. This is a just MAP sensor after-all, so it should be reasonably accurate.

[RusH_]

Working, or working accurately?

Working the way it should have been from the factory, how accurate that is i don't know, but i think jrm has covered it above

[Maccar34]

I have this problem too so I'm going to give this soldering thing ago. Thanks for the help

[JCskyline]

Hey i just followed your guide and my boost gauge works now thanks heaps i used a small flat head screw driver to pop off the 3 clips and i found removing the screw that hold the booster sender unit makes it easier to manuever the unit when u wana pop the clips off and take out the pcb board. thanks alot once again. hope this helps others.