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Discussion Starter · #1 ·
Good morning,
Iam new to this forum, my name is Benni, Iam 33 years old an live in Germany.
I recently bought a Commander with 1500 miles on it, it was very cheap because it has limited power and speed.
It runs maybe max 38 miles per hour and the acceleration is like a starting train.
The engine is okay, it is like a new one, we replaced both spark plugs and the fuel pump like described in some other posts.
There was no effect, it maybe runs a little bit better.
After that we checked the cdi, the main control unit, there also is no failure or error on it.
My keys are also performance keys.

Lastly I bought a used Power Commander, we build it in and also no effect, again it runs a little bit better, but there are missing 3/4 of the horse power.
I did everything you posted in this forum, maybe you have some other good advices for me.
Otherwise my last chance is the can am dealer, but than it will be very expensive I guess.

One last info, the engine itself is good, It runs smooth and starts good.
The first seconds of acceleration the commander wants to use all power, the wheels also spin on then street, but then something limit the power.

Regards from Nuremberg, Germany
Benni
 

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Black key performance full power

Gray key work 38 to 40 mph

Orange key safety 25 mph

But any color key can be programmed with buds to and mph setting. But machine and key has to be present for the key to be programmed.


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I would assume that you've already checked for a restricted intake or exhaust? If you're running in high gear, does the dash indicate so? (assuming you don't have a 'sport low' mod) You said you replaced the plugs, but did you verify spark through them (coil output)? If in question, and you have a non-contact thermometer, you could check and compare exhaust pipe temperatures at the cylinder heads. Do you have any history from the previous owner, regarding how the problem started, and what parts were replaced, if any?
 

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what have you done to CVT and belt? any pictures of belt ?
After re-reading if the belt is OK, sounds like you are missing some compression. Suggest a compression check and check valve clearances. If someone has been in the motor and got cam timing off it sounds possible....
For those scenarios, you could put the car on jackstands and if it runs great but no power at ground then an indicator. But you said engine is OK, so the only thing left is getting power to the ground which is belt/CVT or transmission/differential binding (not likely).
Or have you checked the throttle linkage to make sure throttle plate is calibrated properly? But you said engine is OK? Isn't that a cable to throttle????/ stretched????
 
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what have you done to CVT and belt? any pictures of belt ?
After re-reading if the belt is OK, sounds like you are missing some compression. Suggest a compression check and check valve clearances. If someone has been in the motor and got cam timing off it sounds possible....
For those scenarios, you could put the car on jackstands and if it runs great but no power at ground then an indicator. But you said engine is OK, so the only thing left is getting power to the ground which is belt/CVT or transmission/differential binding (not likely).
Or have you checked the throttle linkage to make sure throttle plate is calibrated properly? But you said engine is OK? Isn't that a cable to throttle????/ stretched????
No throttle cable . Throttle by wire.


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If you are say it’s all good to 38 then just stops climbing. I would get a inline spark checker so you can see what kind of spark you got going to the plug . And while checking spark I would buy another spark plug and replace one cylinder. Run it then take the one you removed and move it to the other cylinder.

Running great to 38 to say 42 mph is a really good sign that you are only running on one cylinder. 9 out of 10 old school commander will run good without missing but top out between 38 and 42. It take two cylinders to get the machine above 40 mph. And many on this forum have replaced plugs only to have a new plug bad out of the box .


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Discussion Starter · #9 ·
I would assume that you've already checked for a restricted intake or exhaust? If you're running in high gear, does the dash indicate so? (assuming you don't have a 'sport low' mod) You said you replaced the plugs, but did you verify spark through them (coil output)? If in question, and you have a non-contact thermometer, you could check and compare exhaust pipe temperatures at the cylinder heads. Do you have any history from the previous owner, regarding how the problem started, and what parts were replaced, if any?
The dash shows everything I do, we tried every setup possible.The old spark plugs had a very good color, nothing unnormal.
Intake is fine, we did not deassemble the exhaust so that will be my next lookup.

I also will try it with the tires in the air on jackstands.

The previous owner said, It started after he did not used the Commander for a few weeks.
He put It to the can am dealer, they said, It is the main control unit and that was all, he then sold the Can am.
 

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Discussion Starter · #10 ·
If you are say it’s all good to 38 then just stops climbing. I would get a inline spark checker so you can see what kind of spark you got going to the plug . And while checking spark I would buy another spark plug and replace one cylinder. Run it then take the one you removed and move it to the other cylinder.

Running great to 38 to say 42 mph is a really good sign that you are only running on one cylinder. 9 out of 10 old school commander will run good without missing but top out between 38 and 42. It take two cylinders to get the machine above 40 mph. And many on this forum have replaced plugs only to have a new plug bad out of the box .


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Allright, I order some new plugs and try this one again.
Can you also imagine that the fuel pressure is too low?
 

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Fuel flow could be suspect, but ruled that out since you put on a new pump. But could be if you had a line or pickup restriction. The static pressure at idle could be good, but not enough volume or flow when running when high delivery needed. And maybe to Acefires point, one cylinder/injector could be the culprit, plug color could be an indicator.
 

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Fuel pressure should be 50 psi at its lowest point from idle to wide open throttle. Factory setting on the regulator is 52 psi. But they will run fine with 50. Once they get to 48 or lower it’s done . You can borrow a inline fuel pressure test kit from auto part store. I have a list of auto part store replacement pumps if needed. About one third price of new dealer pump.


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Discussion Starter · #13 ·
I ordered new plugs and we will check the fuel pressure.
My friend ows a car repair shop so I have access to all the tools.
We repaired the fuel pump with a repair kit from allballs, I think it was 100 Euros.
Thanks for the warm welcome and the help.
I will keep you updated
 

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I know everyone like the all-balls prices . But they sale some of the cheapest Chinese parts in the market . Won’t be surprised if that’s not your problem.


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Discussion Starter · #18 ·
I know everyone like the all-balls prices . But they sale some of the cheapest Chinese parts in the market . Won’t be surprised if that’s not your problem.


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Hi again,

Quick update, It runs on both cylinders, the plugs are good.
The all balls fuel pump produces 52 psi, sometimes 51.5 psi, but never under 51 psi fuel pressure.
Seat belt is clicked, Performance key is in use, It also says performace mode.
It is even limited on a jackstand.

I think it runs in work mode.
Next step is reading out the main control unit, I found a guy who has the B.U.D.S diagnostic software.
 

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Benni,
At your max speed of 38 MPH, what is your RPM?
It sounds like your gearbox may be jammed/locked in low range, there may be a broken shift fork in the gearbox even though the display and gear position sensor (GBPS) may be indicating high.
If its running fine I would start by putting it on jack stands and confirm the gear box is indeed switching from low to high.
Another thing I'm going to throw out there is maybe mice chewed some wires somewhere. very common when sitting for extended period of times...

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