boost gauge question- jump around a little at full boost?

[Bmxr152]

I have a Greddy electronic boost gauge. I was wodering if the gauge should jump around a little at full boost. At like 15 psi the gauge will go up and down about 1psi quickly and then by redline end up at 17 psi. I know i have some creep issues but could the quick fluxuating of psi at WOT be from boost leaks or is that just normal wiht the electronic gauges?

 

[John_GST]

I dont have an electronic boost gauge, but i have an electronic oil psi gauge and every now and then it tends to bounce a little. I would guess that it is the electronic sender, but do a boost leak test just in case. Good luck with it I hope this helps a little if any.

 

[98gsspy]

Make sure you don't have too many items running on one 12v source. 1 psi is not much but if it is fighting for power it might cause your jumping.

 

[Ginglingston11]

I have an electric Autometer gauge and i have never had a problem like that

 

[brute]

Does the car feel normal when the gauge is bouncing. Because it might be a real problem, and the boost gauge is just reflecting that. Does the whole car shake or stutter when the gauge is dancing?

 

[Mikelb]

What is your boost set to?

I'm assuming that your wastegate is opening and closing really fast. That will make your boost flutter a little. The fact that you're creeping tells me your boost is too much for the wastegate, so I'm assuming that the problem lies there.

Does your car seem to cut out a little around 15psi? Like it almost stops gaining boost for a second (still accelerating, boost just stops climbing momentarily). That's about where my car has problems with the wastegate.

 

[Bmxr152]

Its running normal, just the jumping around of the needle had me worried.Boost is set at 15 psi.

 

[jiggysnitz]

Try turning off as many things that use up electrical power as you can (lights, stereo and so on) and see what it is like, then turn everything you can on and see if there is a difference because that would show if its just not getting enough power.

 

[endeffect0]

Jumpy needles on electric gauges can be caused by poor grounding, not just on the sensor but also on the rest of the car, check all your engine grounds and battery wires/ terminals. Make sure all of them are making solid clean connections and none are warn out, corroded or frayed. If any of them are they could be causing 'electronic noise' that would be picked up by the gauge. If you don't have an actual problem with maintaining steady boost there is a good chance that could be it.

 

[truwarrior]

I'm having the same issue. Even with the EBC off. My EVOIII will hold to 10 psi then creep to 15 then start to flutter up and down by 1 or 2 psi till redline. I'm going to disconnect the wastegate flapper tomorrow to see what happens.

 

[truwarrior]

I disconnected the waste gate flapper and got the same responce. Slowllyyy built boost to about 15 psi the higher the boost pressure and rpms went the most the rapidlly the needle moved back and forth 1 or 2 psi. So I guess at this point it might be a boost leak or exhaust leak some where?