Hello everyone,

After 5 months of work on this car, I finally went out to test drive it after fixing my injectors issue (cf my previous thread: Issue on a European RX7 FD (gas leak) - RX7Club.com - Mazda RX7 Forum).
The car drove amazing, and it seems I just have to re adjust my idle properly because it's bouncing a bit most likely because we messed up with it.
However I'm a bit confused by my boost reading from the gauge I installed in the car.
0 when the car is off
-0.7-0.6 when idle / low rpm and whenever I go WOT the gauge goes to about -0.2-0.1, the car drives fine and seems fast without any issue (besides the usual small hesitation sometimes at 3k RPM), and I can hear the blow off valve when I'm lifting the trottle.
Is it just me who doesn't know how to read a boost gauge, or am I having an issue such as a vaccum leak ?
Gauge is a Prosport JDM in Bar.

Thanks in advance for your wisdom, the forums have been a great help to fix this car;
Clément

 

the vacuum/low rpm reading sounds right, when u floor it it should jump right to near zero instantly then start climbing as boost builds should get up to about .7 bar. in full boost. what line did u tap into maybe you connected it to something that does not see boost?

 

Yellow arrow marks the nipple where I connected my boost gauge. Normally, it is capped.

 

I just double checked, I may have indeed plugged it on the other nipple (blow-off HKS).
The second one we had replugged it with one hose that seems close but not plugged, but after checking the diagram, it is the one controlling the charge relief valve that I don't have anymore, since the previous owner had installed an HKS Charge Relieve Valve.

I'll swap it around and go do some testing, but I'm pretty sure my boost reading should be good afterward.

 

IMO one of those ports on the manifold should be dedicated just for the boost sensor. The other can be used for a gauge.

 

I just got back from a quick drive and the gauge is reading correctly now.
I also fixed my surging idle with some tweaking to the 2 screws in order to be back at 800rpm.
The last issue remaining now, is me being too scared to go all the way on the gas given how fast this car is ha ha.

I just need to pass MOT now to be fully legal and back on the road to make these doritos scream.

Thanks a lot everyone !

 

Update: I passed MOT last night, the car is fully legal and back on the road