Boost gauge showing 0.0

[Billgluckman]

Just got odometer and boost gauge working at its showing 0.0. I've checked for vacuum with my finger and there's definitely vacuum on the line going to the boost control actuator but nothing on the other side of it whether at idle or rev.

 

Is this a bad actuator? The lever moves freely.

[Imp558]

MAP sensor does the boost gauge, I'd think there would be a code in the PCM.

[Billgluckman]

But if there's no vacuum wouldn't the gauge read zero? I've got a lot to learn on this engine

[Imp558]

Sounds like a bad sensor. Earlier cars had a second MAP but I think yours just has one.

[Billgluckman]

No map sensor code.

[Imp558]

This is in the DIC? Or a dedicated gauge?

[Billgluckman]

It's the factory gauge in the cluster.

[Imp558]

Hmm, Alldata doesn't show it. I'm not sure how it works if it isn't class II data. Too bad our primarily Admin isn't around, he has a second gen GS and I'm sure he knows how it works.

[Billgluckman]

Hopefully someone will come along because I'm stumped. I found a vacuum leak and fixed it but gauge still reads 0.0.

[digitaloutsider]

Tom is correct, the DIC gets it's information from the MAP sensor. It's passed via Class II data. If you aren't reading boost on the gauge either the MAP is fucked or unplugged. Or there is some wiring issue between the MAP and the PCM.

[White93z34]

Is the boost control solenoid working?

[digitaloutsider]

I guess that's a good qualifying question.. I'm assuming the car is actually boosting, right? When you rev it, the BBV shuts, correct?

[Billgluckman]

Tom is correct, the DIC gets it's information from the MAP sensor. It's passed via Class II data. If you aren't reading boost on the gauge either the MAP is fucked or unplugged. Or there is some wiring issue between the MAP and the PCM.

Map is plugged in. No map sensor code, how can I check it?

 

Is the boost control solenoid working?

How would I verify its working?

[digitaloutsider]

Open the hood and rev it, watch the lever on the BBV. It should close when you rev it and open when you let off.

[White93z34]

you can also test it with multimeter on OHMs setting 10-15 ohms should be normal.

 

or apply 12v to it and you should hear it shut.

 

Its right by the boost bypass valve

[digitaloutsider]

That is the boost control actuator, and shouldn't be doing anything unless it's for some reason stuck open. You can unplug the electrical connector altogether to rule it out, it's not necessary for the test.

[Imp558]

does that cars gauge show vacuum and boost? If it's not showing vacuum but it's supposed to then we're likely looking at a faulty component. If it shows vacuum and not boost then we are looking at overboost solenoid.

[digitaloutsider]

Boost only, no vacuum.

 

OP, if you have a scantool, you can see MAP output.

[White93z34]

If the solenoid is bad, no boost for you.

[Imp558]

If the solenoid is bad, no boost for you.

Boost Nazi: "No boost for you!"

[Billgluckman]

Ok let me try to catch up. I can rev the engine and the bypass valve lever moves. I also ohm'd the actuator a few days ago, 25ohms if I remember correctly. I do have access to a scan tool, hopefully I can get it this weekend.

[Billgluckman]

Also I just drove the car for the first time. The car seemed to run good, didn't feel lazy or anything but I leaned into the throttle and it ran up to 4K rpm and boost gauge still read 0.0