Nytro MCX goin lean

[lowmark]

Anyone have an issue with the injectors not firing and running so lean it shuts down after about 5 psi? Tried everything including another ecu box.

 

[lowmark]

How many actually have one, I assumed that there was some out there running??? or is this the only one with this problem?

 

[nitro express]

Haven't heard of that problem..I did hear about water gettin in the box tho...maybe that????

 

[snowy1]

this is the first I have heard of this problem, are you sure your wiring is correct.

 

[ken_climb]

You might find more help over on the snowest forums "yami section" There are at least 50 guys over there running these. Out of the 6 guy's that I ride with who run mcx nytro's we havn't had any issues like this. Did it ever run right ? or is this something that "hust happened"??

 

[mahaman]

lowmark - did it ever run correctly on the turbo? Do you know if it is a cylinder or all cylinders going lean? I have a similar problem on an APEX mid-mount I am trying to figure out - #4 goes lean as #2 goes rich at 7000RPM. Haven't swapped the box yet but am working on that.

 

[HAMMER]

lowmark -- Need more information. What did you try besides the controller? Could be many things, could be a power supply to the controller issue, could be a pressure signal to the controller issue, could be a lot of things power, pressure, ignition, injection related.
mahaman -- Looks familiar ... from DYNOTECH

2/5/2008 Sean Ray's MCX turbo Apex is still on the dyno ... Problem of air distribution in plenum ??? All four injectors are firing perfect. At WOT 6000rpm all is perfect, let engine slide slowly toward 6500rpm and cylinder 2 leans out. Then as revs are allowed to slowly slide up toward 7000rpm cylinder 2 enriches getting fatter than cylinder 1 & cylinder 3 (which stay perfect) then cylinder 4 leans out and misfires. Is plenum design allowing it to get more than it's share of air robbing from cylinder 2 ???

If cylinders 1 & 3 are consistent I would be more suspect of fuel delivery than air delivery. In my case (Supercharged Apex) the plug-checks tell me that cylinder 1 is my rich cylinder and cylinder 4 is my lean cylinder. My charge air tube enters on the cylinder 1 side of the lower tank. As air flow and velocity (boost) increases I'm assuming the air stacks (ends up being more dense) in the cylinder 4 section of the intercooler causing this. The plug-checks also show me, by coloring, that the air fuel ratio gets progressively leaner from cylinder 1 across to cylinder 4. I’ve staggered my CO adjust to help compensate for this and it has made my plug coloring more uniform but the CO adjust wasn’t meant to work throughout the entire range of fuel control so cylinder 4 is still my leanest plug reading when running it hard.

 

[lowmark]

new install of mcx kit, the injectors will not fire at all, so #*$&@ soon as there is enough boost it will kill the motor. Tried many things and triple checked all wiring, including the wires in the proper places in the plugs. I'll let you know once we find it. Thanks.

 

[PwdrNut]

Which EFI box do you have? The new or old style. Check with your dealer or pm me about connecting the injector wire "second" connection.
If the injectors are not firing at all, this should cure the problem.

 

[snowy1]

I sent my box off to the dealer for a remap, and now it appears my secondary injectors are not working, worked fine befor just had a little stumble on the bottom, now no stumble but no fuel as the boost and rpm go up so do the a/r readings, I ahave sent the box back to get rechecked.

 

[lowmark]

not sure on the style, didn't know that there were different ones, I guess this may be the issue after all, I had a new kit in stock and tried the ecm out of that kit and same problem, so I'm kinda thinkin I may have two bad ecm's. Time to call sweeden again.

 

[PwdrNut]

The newer style box is about 1/2" thick with two small wire connection points on the face. The older style is about 1 1/2" thick with one large wire connection point on the bottom.
The chance of two EFI boxes with a bad injector signal is slim as this is a very rare occurance, although possible. But I believe the chance of both injector signal locations being bad is even less likely as I don't believe it has happened. If you can change the wire location for you secondary injector signal on the EFI box, it should solve your problem.
Re-mapping an EFI box should not cause this issue.

 

[rxrider]

Are you absolutely positive that you have the connector to the MCX fuel injectors plugged correctly, meaning that you have verified that electricity goes past the connector.

My friend did detonate his '06 Apex from because he had not seated the connector to the injectors correctly. :-(

 

[lowmark]

Thanks for the replies guys, The MC-X ECU was faulty, with a new box the sled runs fine. Thanks for all the replies and help.

 

[rxrider]

great to hear she is up and running

How's snow cover in Alberta, when does your trail system close down? Our trail system is open until May 5.

Ride safe and have a blast for the remainder of the season.

Jan-Ove
rxrider