I was setting in the parking lot of McDonalds eating and let my truck idle while I was doing that. When I finished I headed down the road and noticed my Edge Evolution II was showing a -4 PSI on the boost. I noticed that it seemed like it has less power and I'm not seeing a positive boost pressure unitl around 2100 RPM's. Once I hit 2100-2200 RPM's it feels normal and I was able to hit 15 PSI with the Edge set on 60hp tow. 15 PSI is a little low but it didn't feel any different in that RPM range. Is a negative boost pressure even possible? I have a small leak in my driver side up pipe where it goes into the y collector but it's not real bad. I haven't got to go out and inspect my IC boots yet to see if a new problem has occured but I will shortly. I've heard of low boost but I've never heard of a negative boost pressure!

 

I just did a search and saw where a couple other guys had this problem and they too were using an Edge programmer. Apparently the Edge can cause this and both said that their truck ran like poop. Gonna reset the Edge and see if that takes care of it for now but looks like I'll be selling the Edge and getting a good tuner. I'm gonna hook up a mechanical Autometer boost guage I have and see how it compares to what the Edge is saying as well because I have always felt that my truck was making more boost than what the Edge was saying anyway.

 

How air filter look like?

 

Brand new Wix 6637.

 

Sounds like the sensor is FUBAR.

 

I've been having that suspicion. Today's issue can't be just that sensor though. It must be the Edge programmer today cause it's doing the same thing the other guys I read about experienced with their Edge. All of the other times that I've suspected it was making more boost than the Edge was showing, it was running fine but I just felt like the Edge was showing less boost than what it was actually making. Today it felt like a sick dog until it got up to around 2100 RPM's. Soon as my little girl's momma gets off work and takes over babysitting duties, I'll go inspect everything and reset the Edge and report back.

 

Might be a good idea to thing about traditional gauges. Definitely try running it without the Edge, and see what it does.

 

Checked the IC boots and they all look good. I reset the Edge and it's fine now. The Edge is now on eBay. When it sells I'll be ordering a DP tuner. I already have a pillar pod and an autometer boost gauge, just need to get a pyrometer for the pillar pod.

 

i would look at PHP also they have a good reputation
i should be getting mine middle of the month!

 

The Edge is reporting the signal on the PCM bus. The programmer should not play any part in this signal. Over the years I have seen a negative reading twice on my Edge, in stock, using my Dp. Both times a key cycle cleared the issue. Do some searches on the MAP sensor, I seem to remember there are voltage checks you can make. If you have a persistent signal bias I would lean towards a grounding issue or a bad sensor.

 

My Aeroforce Interceptor Scangauge reads "negative pressure" at an idle and always has since it was installed. I have yet to compare the "manifold gauge pressure" reading on my AE to the Scangauge. I talked a little with Jody@DPTuner about my gauge readings at RRE this summer and it seems that this negative pressure reading is a normal occurrence. I will look more closely at this and report back. I am not monitoring boost with my Scangauge, right now, and will have to set it scan that parameter.

 

My Edge has showed a negative boost pressure twice before this. Both times I was idling thru a parking lot and as soon as I pulled out on the road it went back up and there was no loss of power so I didn't think much about it. Today however, there was a huge loss of power and the boost PSI stayed in the negative until I reached 2100 RPM's. I know that the programmer has no control over the turbo and shouldn't effect the amount of boost it's putting out. I'm thinking it was more of a fueling issue which would be effected by the programmer. Plus once I reset the programmer, all was normal again.

 

The power loss is interesting. I'm not necessarily sure it is the programmer. The programmer reflashes the PCM SW and then is pretty much along for the ride, i.e it's not in the loop. That reloading the program seemed to help is great. Maybe the PCM got confused along the way?? Hard to say. Fingers crossed that it was just one of those mystery event that is now solved.

 

I sure hope so. I found it interesting that two other guys had the same thing happen while using the Edge in a thread I found when I did a search. In both cases, resetting the programmer solved the issue. If it doesn't meet the reserve price on eBay, I'll just set it back to stock, leave it hooked up for the gauges and code scanning and get a DP tuner.