High Boost

[ASmitty]

Hitting 12 psi normal with these mods?

Vibrant Exhaust
Unichip, low boost setting
Upgraded SMIC
Hardpipes
Injen CAI

God im afraid!

 

[jmv]

Well high boost setting on the unichip is supposed to spike to ~13, then hold at 10. Are you spiking to 12 or holding at 12?? If your boost is too high, you can have it retuned by an authorized unichip dealer (you might also shoot a PM to JDM Sam), but be warned that if you have a vacuum/boost leak, such as your wastegate actuator is torn or your vac lines have worn out, then a boost tune won't do you much good, since leaks lead to spiking and other problems.

Lots of people have ditched the boost controller on the unichip because even when the spike has been tuned out as best as possible, it never entirely goes away. Food for thought.

 

[ASmitty]

spike to 12 holding around 8

 

[ASmitty]

hi boost setting spiking to 15

 

[ASmitty]

also checked the wga, it held pressure

 

[GhostMercury]

that doesn't sound rite

 

[jmv]

spike to 12 holding around 8

hi boost setting spiking to 15

wait so you're saying with the boost controller turned OFF, you've got a 12 psi spike, and then when you turn it on it spikes to 15??

Whats your vac reading?? I would definitely reccomend NOT turning on high boost at this point, and definitely being careful even at 'stock' boost if you're hitting 12 psi. Something is wrong.

 

[ASmitty]

under 10 in hg, around 5

 

[dirtysouth_msp]

You have a major vac/boost leak somewhere.

 

[ASmitty]

carb cleaner easiest way to find a leak?

 

[jmv]

well i would reccomend just replacing all your vac lines (or at least the smaller ones off the intake mani and to the bypass valve and wastegate) with high quality silicone stuff. Mazda used fuel line for vac stuff, which isn't designed for all the levels of heat in the engine bay (our cars seem to get particularly hot under there), which leads to them deteriorating. Also make sure you check out your wastegate actuator.... find the vac line running to your WGA, pull it off the tee, and blow into it. If air goes through, that means your wastegate actuator diaphragm is torn (or that vac line is crap). Either way, that can be a big cause of boost/vac leak. ATP makes a replacement thats much cheaper than the OEM, you can get one from www.*************.com if that is in fact your problem. They also sell quality vacuum line. Be careful with what silicone vac line you go with, because if you buy cheap stuff it is known to sometimes collapse, restricting air.

 

[miss_steele_msp]

I had the same exact problem. I had my boost controller hooked up wrong. Nothing was hooked to the nipple coming off the vavle cover pcv valve I think?

 

[jmv]

well FWIW i've been told by people i trust fairly well that the PCV side of the boost controller doesn't need to be hooked up.... regardless a vac reading of 10 or even worse 5 is totally wack. It should be 20-22. I'm having problems just because of a vac reading of 18....

 

[miss_steele_msp]

well FWIW i've been told by people i trust fairly well that the PCV side of the boost controller doesn't need to be hooked up.... regardless a vac reading of 10 or even worse 5 is totally wack. It should be 20-22. I'm having problems just because of a vac reading of 18....

Well mine wasn't hooked up and my boost gauge was reading 9.5 and spiking to 12 with the boost controller turn all the way down. found out that wasn't hooked up and it fixed the problem.

 

[jmv]

okay well then make sure that line is hooked up, but ASmitty you still have a massive leak somewhere you need to track down.

 

[ASmitty]

I took a look at all my lines, and everything looked correct, even though the unichip install instructions suck D:

Sprayed carb cleaner all over every vaccum hose and never found anything either! Blew into wastegate acutator and it held pressure. Running out of ideas..maybe the ebc solenoid is screwed, and it cant regulate boost even when turned off?

 

[jmv]

if you're at ~5 vac at idle, theres something wrong besides just the boost controller. Be aware that some of the vac lines have 'coverings' (at least some of mine do) so the actual vac line could be torn under the covering. I'm not sure of the best way to check for vac leaks, but i do know people reccomend running a little seafoam through the engine for it. Theres probably someone who could help you out more definitively in this area than i could....

 

[ASmitty]

I've been think maybe its my gauge............my car idles perfectly fine for something with non exsistant vaccum pressure.......

 

[ASmitty]

anyone else, ideas or inputs?

 

[hotrodf1]

Try hooking up a regular vacuum gauge like the kind that mechanics use. Then you could at least check to see if your in car gauge is right or not. The gauge will come with a T and some vacuum hose so you can just disconnect one line and add in the gauge.

Would think if you were only pulling 5" Hg at idle the car wouldn't actually idle. My big roller cammed camaro idles at 10" Hg and idles pretty rough. Surely you can't be pulling 5" at idle.