MAP signal and power logger

[turbobob924]

I have a power logger and the GNX dash so my stock LED boost gauge is not connected. I found that without the gauge there was no 5v source to the MAP sensor. I spliced in the green wire to the MAP sensor to the 5v reference off the ECM. I now have 5vots to the MAP but power logger shows super high boost. The signal wire from the MAP show like 4+ volts all the time.

Could a ground problem with the black wire to the MAP cause these really high readings?? I can find a wiring diagram that shows where/how the ground wire is grounded only via the LED gauge.

I checked and it is the 3Bar MAP and power logger is set for 3Bar.

The Powerlogger has a calibrate function but it doe snot seem to work?

I read the write up on vortexbuicks on how to hook up the MAP for power logger to see this analog input.

Any ideas?

 

[Sweet6]

I thought you could "adjust" the power logger for the variances in the volts.

I have noticed the high boost readings on the few cars I have seen. So I think this is somewhat normal to occur.

Hopefully someone that has done this will chime in.

 

[TurboDave]

I have a power logger and the GNX dash so my stock LED boost gauge is not connected. I found that without the gauge there was no 5v source to the MAP sensor. I spliced in the green wire to the MAP sensor to the 5v reference off the ECM. I now have 5vots to the MAP but power logger shows super high boost. The signal wire from the MAP show like 4+ volts all the time.

Could a ground problem with the black wire to the MAP cause these really high readings?? I can find a wiring diagram that shows where/how the ground wire is grounded only via the LED gauge.

I checked and it is the 3Bar MAP and power logger is set for 3Bar.

The Powerlogger has a calibrate function but it doe snot seem to work?

I read the write up on vortexbuicks on how to hook up the MAP for power logger to see this analog input.

Any ideas?

You need a good stable source for your 5v and gnd. Tapping into the tps wires for this is a good source.

Double check that you have a 3 bar map. The stock unit is only a 2 bar.

 

[turbobob924]

I will replace the ground wire and I know it is a 3BAR MAP cause I bought it at Caspers last year.

 

[Sweet6]

I have seen cars even with the 5 volts from the TPS read high.

 

[turbobob924]

Well here we go again with ground problems!!

I go home form work and taped into the MAP ground wire to a good ground and now the voltage with key on and not running is is the right range @ 1.5ish volts!

So I will do some more test and tunes later this week and see the data but I think the MAP reading will be OK. I'm still trying to chase down the MAF noise though.

 

[TurboDave]

You've got some seriouos grounding issues in that car. I'd highly recommend Caspers ground stretcher kit!!!!!!

 

[turbobob924]

LOL

I already have the ground stretcher kit!!

 

[TurboDave]

Hmmmm.

 

[Razor]

Key ON 1.6vdc. The higher the altitude.. the lower it reads.

HTH

 

[turbobob924]

I fixed the MAP signal issue but still have major MAF noise drop out at WOT!

 

[that guy]

I fixed the MAP signal issue but still have major MAF noise drop out at WOT!

Sounds similar to something I felt like I was chasing my tail on. I kept thinking it was MAF drop out. Check your battery cables.

I had replaced both mine from Caspers electronics a while back. Don't know why the wire from the alternator to the battery was soo long. I had broke my torque strap bolt prior to the problem starting and got it fixed, didn't think to check my battery cable. When I broke it, it was allowing the motor to torque over. Allowing the something hot, probably exhaust, to come into contact with that wire. Melted the protective coating and into the wire.

 

[TurboBob]

I spliced in the green wire to the MAP sensor to the 5v reference off the ECM.

Any ideas?

5 Volts goes to the Gray wire I believe.........

 

[turbobob924]

Hey that guy. Not a bad idea but shouldn't the volts readings also be bouncing around in either direct scan or powerlogger if the battery cable was loose??