951 Di hard start/check engine light

Note: This site contains eBay affiliate links for which SeaDooForum.com may be compensated
Status
Not open for further replies.

Shane0306

Member
After a recent rebuild I think I may be stuck, won't rev the full range (estimated it stops climbing around 3.5k - 4K Mark)
Very hard to start (but once it starts it idles nice)
And is spitting out a check engine light
Every connector on the MPEM is corrosion free and have even cleaned the pins if they looked like dielectric grease had gotten too close.
I have checked the air compressor, everything is good there.
I have still yet to test the TPS but I highly doubt anything sinister there.

Any other suggestions?
I'm running out of ideas.
 
DI skis are no fun when they are not running right...

First thing I would do is confirm compression, I don;t think that is your issue, but good to know the Base Engine...

Second thing, Fuel Pressure... The DI Ski idles at 117psi if I'm not mistaken..
 
Tell me about it!!!

I did a compression test not that long ago and I was between 135-140 psi

Are you saying fuel pressure from the pump in the tank?

Or the air compressor pressure?
 
I only know what I know from reading,,, so bear with me.. The 117 is combined pressure. I have seen the two pressures listed separately, but don't recall what they are. FP is very important when it comes to DI skis. So doing a compression test and Fuel Pressure test are important in regards to diagnosing DI skis..
 
Why wouldn't it? It may not trigger the light on it's own fault, but the poor running could easily throw a check engine light I would think..
 
True, true, okay I will investigate when I get home from work and see what it reads!

Also do you know if I have to physically reset the check light if it's been activated? Or will it turn off on its own?
 
In most cases, the light will turn off once the problem is solved. It will normally keep a "Historical" code which can be seen with a computer,,
 
I believe the fuel pressure is 27+80 which equals the 107 pressure required to properly run the di. The pressure actually goes much higher than 107 at full rpm. The 27 is fuel pump pressure and the 80 is from the air system.

Also,
Low fuel pressure will not throw a check engine light. Low pressure and holding WOT and not running right may... Fuel pressure needs to be spot on for the di or you will have all kinds of weird running symptoms.

Hope this helps.
 
I tested combined pressure and it was higher than 100 psi... It was a quick test, I will have to do a more thorough test but I'm confident we can eliminate fuel pressure.

Where can I get my hands on a scan tool? I feel like I need to get a code out of it know what the thing is carrying on about.
 
Even at 100-105 the pressure is not enough. It can still have issues. So don't rule out fuel pressure completely. In the water under load if the pressure drops below the magic 107 number you have a fuel pump or air compressor issue.

Candoo pro or budds are the tools that can read it. I think candoo runs about 400 for a single machine license for home use.

Have you changed the regulator/rectifier?
 
Last edited by a moderator:
Last edited by a moderator:
Damn, I wonder if my local shop can scan it for me

No I haven't changed the regulator/rectifier, do you suspect it's causing issues?
 
Coaster Joe, does the scanner also do 4-tec as well?

That would probably come in handy later on down the track for my Wake.
 
The most common issues on the di are regulator/rectifier failure or fuel pressure issue.

When the regular fails the ski goes into limp mode and won't rev all the way up. I would still verify you have the correct fuel pressure though. I suspect a failing fuel pump. Your ski is behaving the same as one of mine did when the pump went.
 
Damn that's probably what's happening, beeps for about 3 seconds every 2 mins when running?

Although, before you start the engine technically power is sustained by the battery, why would a reg/rec make it hard to start? Confusing.

Maybe the pump AND reg are gone.
 
Could be one or the other issue or both. Tough to say. I think step one is candoo to read the code. Also. If you test the fuel pressure when the key is placed on the post you should have 27psi which is required to start the ski. That would be a good test to run as well to troubleshoot the hard starting
 
CanDoo Pro is priceless when you have issues,,,

And I agree with the others,, you need to make certain of the Fuel Pressure Specs.

Fuel Pump alone and then combined with the booster... Fuel pressure is VERY critical to this ski.

And the rectifier is as well.

DI ski's are a finicky beast,, Battery voltage as well for this ski is VERY important... Must be above average.
 
Status
Not open for further replies.
Back
Top