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Anyone use a Powercommander on an APEX with boost?

NHBoy

NHBoy

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Joined
Apr 3, 2007
Messages
37
Location
Southern New Hampshire
Got an 07 APEX with a Stage 1 MPI supercharger on it. Having cold start issues (starting 3 - 4 times before it stays running). I have been told that the controller I got from MPI can only add fuel to the idle circuit after it has been powered up.

Looking for better cold starts. I've used the Powercommander on a cat before and there are lots of data points you can change to get the entire curve right.

Anyone try the autotune? Looks like the cats meow!

Thanks for the input.

Marco in NH
 

FLYBYU

How difficult was it for you? Literature states plug it in and away you go, no tuning. True? Do you set target A/F ration and that's it?
 
That's really about it. I was the first, so I spent the winter setting it but now It's good. And there's other with it now. Turbo and supercharger settings are different. Mr. Sled has one also and be able to get you a map that'll get you close.
 
Like Flybyu said, i have pcv with autotune on my supercgarged sled, so far works way better then the gems box.
 
What is your cold start issue? After it fires how does it run now on the GEMS?

MrSled what did the autotune fix for you?

My GEMS unit has been good for me not perfect but good. My sled will be on Ulmers dyno this week maybe if he can show me better power and mpg I will spring for a autotune set up LOL
 
the autotune will set all the trims for you based off a desired afr that you set. Once it trims the fuel and the sled is running to your liking you can turn off the autotune feature and accept trims. Or leave it on and it will always adjust trims as you ride. The afr map and the pressure is the critical part. Kinger you will see better fuel economy with it as you can tune rpm increments in 250 and 500. More precision tuning then a gems box.
 
kinger,

Cold start issue is I must start the sled at least 3 times before it stays running. I could go out right now (about 80 degrees here) and it will start and stall at least twice. On the third try it should stay running and idle fine. This gets amplified when it's cold out. When it's near 0 this process can take 8 - 10 tries. Killed the battery once. It's obviously lean and needs mre fual at startup. Issue I am hearing about the GEMS controller is it does not add or take away fuel until the unit is powered. This is the issue I have. Hate it.

Sounds like you don't have this issue? Any thoughts on a fix? If I could get rid of that issue I would probably stay with the GEMS. It's not perfect but I have an A/F installed. I can adjust for what I want to do at WOT.
 
That sounds like a fuel pressure problem. Yes gems won't do anything for that. Try cycling key a few times letting pressure build up. Most of them will fire and then stall but multiple times isn't right. The PCV can add fuel there but you shouldn't have too. All boosted sleds run on stock injection at idle. The gems box doesn't do anything till it senses boost. On my PCV map the first row all the way down is set to 0 as it doesn't need nothing there. As I'm writing this a supercharger might be different as there's a load as It's started. Mr. Sled. Can chime in on that. I've pretty much used them all just on Turbos though. RB3 and PCV are more time consuming but you can really tune more precise.
 
kinger said:
What is your cold start issue? After it fires how does it run now on the GEMS?

MrSled what did the autotune fix for you?

My GEMS unit has been good for me not perfect but good. My sled will be on Ulmers dyno this week maybe if he can show me better power and mpg I will spring for a autotune set up LOL
Click to expand...

The only reason I went to it was there was a few spots that would still run bad and I wanted to fine tune it and the gas mileage at cruising speed on the GEMS was terrible. There are still a few spots where it is still running too rich but I am working on leaning it out to get her to run great. The main problem with the GENS box is you run out of adjustablility and basically you had to deal with the map that was in it and you only were able to fine tune it slightly.
 
Have you tried just adjusting the fuel ? There is a way to.adjust idle and.low fueling with the Speedo pod. If its running lean or rich on startup this will solve the problem. It will even solve a mild hesitation when you translate from idle to low rpms.
Fuel pressure builds up prior to startup and it builds up quick even if the system is empty. Doudt its that, because after it starts it runs fine right? If it was a fuel pressure issue you would have more problems then just start up. Even if your fuel isdraining out it wouldnt take, more than one cycle of the key to purg the system.I'd try this first before you waste your money and time. Here is the link. Also what is your sled idling at? Sometime all it takes is to increase the idle a bit till it stays running during the first try. Here are the instructions for adjusting your fuel.
Link http://m.youtube.com/#/watch?desktop_ur ... jWsU&gl=CA
 
I agree with flybu its not the GEMS causing this, you have something wrong with the sled. Have you been down the road with the TPS sensor? You can check to see if its working in the diagnostics. Just make sure you unplug the GEMS first and leave it unhooked when you do the check.

Also when you unhook the GEMS the problem is still there. You need to go down the route of vacumn lines, and sensors. What happens if you turn the idle way up to say 2000 rpm will it fire easily then?
 
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