MPI charge teething pains

[shawnmcgr]

So I took my Sapex with stage 1 @ 5psi out for it's first ride of the season this weekend, and first ride with a new gems fuel box. I did take it out once at the end of last year.

Got a few errors: 84, 20, & 15.

code 84 I as expecting to see as I have no BOV, TORS is still active, and I have not stiffened up the return spring yet. I'll live with the occasional 84 for now.

code 20 I had not seen before but figured it was because I was playing with GEMS altitude setting to see it's effects. When I got it back home and figured out the diagnostics mode the atmospheric was reporting 88 and intake pressure 9. When I cranked the motor intake jumped to "ER-1" and the display locked up. Am I getting a correct reading (faulty sensor) or does the GEMS still affect this reading (settings below)?

Code 15 TPS, initially diagnostics gave values of 0 @ fully closed and 27 @ fully open. So I unplugged the sensor and plugged it back in. Now reads 38 and 59. I then check voltages on the wiring harness and get 5v, 2.5v and 0 volts. The 2.5v on yellow wire worries me as I though it might indicate a leak.

Seems weird that both a pressure sensor and TPS go at the same time and right after I install the MPI kit.

I know these GEMS values are wonky but here's where I ended up with safe AFR: 7/4/2/7.5/2.5/5.5.

It was running lean at the top end of green, only way to get it safe was to jack mode 1. Idles like crap. I understand GEMS uses TPS so the faulty TPS would be to blame, I guess. Just wondering about this 2.5v wondering if I have a wiring harness problem.

Thanks for any tips,

Shawn

 

[Srxspec]

You will not get the correct TPS reading with the GEMS installed. Unplug your GEMS and recheck your TPS readings. When you bypass the TORS it usually fixes both the TORS and TPS fault codes.

 

[shawnmcgr]

Thanks srxspec! I disconnected the GEMS and TPS and inlet pressure read good. I expected to get 84 & 15 codes but why am I getting 20? Sounds like by-passing TORS and installing a tether is mandatory.

Did me setting GEMS altitude too high cause the intake pressure reading to read higher than atmospheric sensor and trip the default pressure readings in the ECU? The manual says when this code is tripped it defaults both readings to 85kpa.

I don't get this code 20? I can see code 15 being tripped with 84, I guess.

Taking this thing to Revy in a couple of days...wanna make sure I understand what's going on under the hood!

Thanks,
Shawn

 

[kinger]

It doesn't pay to over think the GEMS I tried...

Unplug it reset everything through teh factory diagnostic fire it up make sure its idling perfect on the factory ECU.

Then connect set up the baseline per MPI, or others on this site, adjust as needed and go have fun.

What I found was that you CAN continually tweak it, like every ride, you can bump up the AFR here or down there, or mess with idle, etc.

Get it so its smooth throughout the RPM range and leave it alone. Let your AFR be .5 point off to the rich, get your idle adjusted correctly at 1500-1600 rpms and use mode 1 to get it close.

Have fun, they are a blast!

 

[shawnmcgr]

Thanks kinger, I've got it idling fine in the shop with and without GEMS. I got no codes without GEMS. When I plugged GEMS back in I got a code 15 and 84 before even starting the sled. No code 20 though and the altitude setting on the GEMS box seems to be affecting AFR again - it had no affect on the weekend. They stopped flashing once I fired the sled up so hopefully the TPS is working.

I'll give it a shot this weekend.

Thanks,

Shawn

 

[kinger]

When you put the key to "ON" but not start it will flash the code mine does, everyone does, you should have no codes while the sled is running though.

Something with the way it interferes with the signal and the GEMS isnt powered on like the rest of the sled with just the key on so it looks like a open circuit.

One thing I never messed with is the altitude setting I went by ulmers reccomendation for sea level since MPI didn't really know at the time.

Good luck and have fun!

 

[shawnmcgr]

Thanks kinger, that clears it up a bit. I thought WTF I just cleared these codes and now they are popping up again!

My altitude is going to change 3-5000ft from parking lot to mtn top so I think I will need to adjust the altitude setting. I'll be careful with my changes though. At least if I get a code 20 I know how to reset it rather than checking sensors next time!

Does your altitude change much in your ride area?

 

[kinger]

No I ride 0-3000ft. Planning on heading west one of these years then will have to get smart. Nice thing is the 4 strokes are forgiving if you do nothing it will run a little rich and no hurt anything, just a little less performance then if it was tuned perfect.

Only thing that is important is to not see your AFR go leaner then 13.5 or higher at WOT, then you need a adjustment, mine bops around 10.5-12.5 at all times.

When riding and your going WOT there is enough room for you to be able to go WOT and therefore enough time so I just take a quick glance make sure I dont see a 13 or 14 and then get back to having fun!

Did you bypass TORS? It must be done. If the throttle sticks there is a big ole red button on top of the bars hit that before you bail LOL

 

[GOTBOOST....]

Do u have any gems numbers that work well at below 1000ft

 

[GOTBOOST....]

on 09 apex stage 1 11psi mpi

 

[shawnmcgr]

Spent three days in Revy and all good. I got 15 and 84 everytime I started it up but they dissappeared after 20sec on idle. I never got another code 20 so I think I tripped that while playing with the altitude setting.

Not making enough boost up top so I may have to go to 10psi sooner than I thought...

Unfortunately I smoked something while I was out there so now I'm replacing my left bulk head!!

 

[kinger]

DOH! on the hit, glad the Sc worked out for you though! They are easy once you get used to them.

 

[347strokin]

Spent three days in Revy and all good. I got 15 and 84 everytime I started it up but they dissappeared after 20sec on idle. I never got another code 20 so I think I tripped that while playing with the altitude setting.

Not making enough boost up top so I may have to go to 10psi sooner than I thought...

Unfortunately I smoked something while I was out there so now I'm replacing my left bulk head!!

That really sucks about the damage!

But get her fixed up soon. I absolutely love the SC's. And I used to ride a turbo at 15lbs and I'm only running my Apex at 12 lbs right now.

I'm riding McBride on Dec 15th, hopefully the snow is good.

The GEMS will definitely work nicely for you once it's set up...good luck!