PLEASE help! 951 di electrical issue

[jhanratt]

PLEASE help! I want to ride!

2001 GTX 951 DI.

One fuel injector sprays the other injector does not. When you switch the fuel injector wires the problem moves so it in not the injector itself.
Where should I go from here?

Details:
2001 GTX 951 DI with 170 hours.
I bought it last year with a burned up engine expecting a to do a top end.
I did fire it up and it sounded horrible but did seem to run.
I pulled it and went with a full premium rebuild on my own block from the Seadoo Engine Shop in Horsham.
Two weeks ago I finally got it back and I paid a Seadoo mechanic to install it because I was too busy at work and I just want to ride.
Friday the shop called and said it's ready to go!

I picked it up and immediately noticed some loose fasteners. One intake manifold bolt was loose and the bracket that holds the exhaust pipe to the block on the starboard side under fuel injection rail was loose.
I complained and they said the mechanic has gone home for the day.

I took it home swearing under my breath. I tightened the fasteners down (with some difficulty because he had miss-aligned the exhaust bracket. I had to remove the fuel rail to align and install the bolts for the exhaust bracket under the fuel rail. I have worked on fuel injection system on cars and diesel trucks and felt confident removing and re-installing the fuel rail.
I tried to fire it but it would not run. It tried to run with some coughing and spitting but it will not go. It is very rough and would not idle or rev.

Yesterday I took it back to the mechanic and they did some testing.
The owner and two mechanics all swear they heard it running good at the shop prior to me picking it up.

I was there today and observed the following.
With the fuel rail pulled up and out of the air injectors so that we can see. Fuel sprays from the rear injector when the engine is cranked.
No fuel sprays from the front injector when the engine is cranked.
When you swap the wires fuel sprays from the front injector and not from the rear injector.
Both fuel injector wire plugs are clean and tight with no corrosion.
I have checked every plug on the engine and computer and all are clean and tight.

Where should I go from here???

PLEASE help..... I want to ride!

 

[racerxxx]

I believe the 951 di idles on only 1 cylinder. You might want to take it to the water and test it on the trailer.

 

[jhanratt]

Thank you very much for your prompt reply.
It does not idle at all. It would not even run on the trailer let alone on the lake.
I read in another active 951 DI post the following from WaarrEagle:

"You will find conflicting answers on internet forums, but I recently consulted a real DI guru and he confirmed that the DI does NOT shut down a cylinder at idle. Non-DI's do this though. There is no mention in the DI service manual of a single cylinder idle. My ski is having fuel pressure problems and will not idle on the PTO cylinder alone. I plan to replace the fuel pump at labor day and confirm for sure that the DI will idle fine on each cylinder alone."

Fuel injectors tested by swapping the wires. Both spray a nice clean mist. (Only the rear harness works)
Air injectors tested by resistance. Same. and they click in your hand when 12V is applied as every working injector should.

Please keep the ideas coming.
I NEED to get this running and ride!

Thanks


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[jhjesse]

You may have a bad wire. Might have gotten pinched/pulled during engine installation???
Open the fuse box and if I remember correctly the two outside fuses are injectors, but just check them all. There are two 15 amp fuses that should control the injectors. There are also two 25 amp fuses that should control the air injectors...or vice versa. At any rate just make sure the two 15 amp and the two 25 amp fuses are good.
I would also unplug the top right connector on the MPEM and make sure there are no bent pin connectors.
Can also run a continuity test on the wire. This will be a bit of a pain as you will need to trace the wire from the injector all the way to the MPEM then ohm it out.

 

[jhanratt]

Thank you for the input.
I tested all fuses for continuity out of the box and put back in the correct place.
I tested the injection wires back to the MPEM and found continuity on one for each plug. A review of the shop manual suggests I tested the wrong 2nd wires. They are not side by side but in separate rows. I have the wire location from the manual now so I can be sure. (tough to read wire colours with an led light) I am off to test again know that I have pin out identification.
I suspect the wire is direct from the injector to the MPEM without a connector can anybody confirm?
I will report back with continuity test shortly.

Thanks

 

[jhjesse]

Yes I believe so.

 

[POPPS]

I would take the arduous task and do continuity test on the non working injector plug harness.,for sure,,to at least rule out a wire/connection issue,,,,,mind you...and I am no DI guy...I hate them...it's always the fuel pump,, and then good luck trying to find an OEM one,,,,,,
,is it possible,,,that the pick up in the front cover is at fault,,,you know...crank sensor,,,I don't think both cylinders fire at the same time,,,like the earlier 800's...not sure,,,a scanner would come in handy here,,,and make sure that the front plug is all the way in,,,happened to me,,,spent weeks,,,I had pulled that heavy pipe,,,and it accidentally pulled the plug out enough to start,,,but to run like crap.,,,pushed it all the way in to "click"...and bingo!

 

[jhanratt]

I will look at the plug on the front.
I have confirmed continuity from MPEM to all four individual fuel injector wires.
Front injector is Pin 7 and Pin 13
Rear injector is Pin 8 and Pin 14
confirmed in the shop manual and tested good.
Every plug I have pulled was clean and dry. The only issue I found was a wire gasket with a twist in it. It is fixed now and the connectors were clean and had not seen any water as evidenced by no corrosion.
Thanks keep the suggestions coming.

 

[jhjesse]

About the only other things I can think of would be the crank position sensor plug or a bad MPEM.

 

[jhanratt]

No easy fix at the front plug. Clean and tight. Fully engaged. All pins straight. Checked with a mirror and flashlight. By the way its a freshwater ski in great shape with no sign of corrosion anywhere.

 

[mikidymac]

About the only other things I can think of would be the crank position sensor plug or a bad MPEM.

Isn't one of the injector plugs the same as something else on these? Is it possible the two electrical connectors are swapped?

 

[Tyman2020]

Isn't one of the injector plugs the same as something else on these? Is it possible the two electrical connectors are swapped?

Not on the 2001 dis no Also check for 6v at the injector plug while cranking

 

[Tyman2020]

And when test continuity are your going pin to pin or back probing

 

[jhanratt]

Thanks for the help guys.

No the fuel injector plugs can’t be put on anything else. But they could get mixed up front to rear.

I tested Pin to pin on continuity. I also removed the pins from the fuel injector plug and inspected the connection. It is bright copper with no corrosion. If you are careful and know how to release the two lock tabs you can do this without damage.

I saw the mechanic probe the fuel injector plugs and saw constant positive power on one side of each of the fuel injector plugs with his test light.

I can test for positive power with a DMM and report if that is helpful. The manual says positive is there and negative is pulsed to drive the injector. (My words but that is the gist of it).

 

[jhanratt]

Update.
I cleaned all electrical plugs at the MPEM with electrical contact cleaner and disconnected the battery. (terminals were all spotless anyway but worth a try).
I left the MPEM out in the sun for a day. (looks mint but you never know)
I put the MPEM back in the and left the pos and neg wires for the battery disconnected from the battery but shorted together. (Sometimes this resolves issues with my 2003 Duramax so I thought I'd try it.)

Last night I reconnected all wires and the battery and tried to start it. It turns over good. It has lots of spark but no fuel smell on plugs or exhaust and no signs of fire at all. Not even a cough.

I did the "quick fuel test" in the service manual. Ie. tether on without cranking should show 27 psi plus or minus 2 psi. When the tether is attached it maxed out my fuel pressure gauge at over 100 psi then slowly dropped into the 80's.

I am thinking when I get a bit of time I will dis-assemble the fuel rail and soak all parts in fuel injector cleaner. Based on the high fuel pressure it sounds to me like the return line is plugged (less likely) or the the fuel pressure regulator is plugged or faulty (more likely).

Advice is GREATLY appreciated.

 

[WaarrEagle]

Update.
I cleaned all electrical plugs at the MPEM with electrical contact cleaner and disconnected the battery. (terminals were all spotless anyway but worth a try).
I left the MPEM out in the sun for a day. (looks mint but you never know)
I put the MPEM back in the and left the pos and neg wires for the battery disconnected from the battery but shorted together. (Sometimes this resolves issues with my 2003 Duramax so I thought I'd try it.)

Last night I reconnected all wires and the battery and tried to start it. It turns over good. It has lots of spark but no fuel smell on plugs or exhaust and no signs of fire at all. Not even a cough.

I did the "quick fuel test" in the service manual. Ie. tether on without cranking should show 27 psi plus or minus 2 psi. When the tether is attached it maxed out my fuel pressure gauge at over 100 psi then slowly dropped into the 80's.

I am thinking when I get a bit of time I will dis-assemble the fuel rail and soak all parts in fuel injector cleaner. Based on the high fuel pressure it sounds to me like the return line is plugged (less likely) or the the fuel pressure regulator is plugged or faulty (more likely).

Advice is GREATLY appreciated.

You saw over 100 psi with just the lanyard installed and not cranking? If so, that is definitely not right. You can take the whole fuel rail apart and pretty quickly confirm that all passages are open/flowing. Not sure how a blocked fuel return or passage would explain you whole issue, but you never know.

 

[jhanratt]

yes agreed it could be a secondary issue but it's still a problem and it does appear to be the first test in the fuel management chapter in the service manual. I was thinking I would run through all of tests before I invest in an MPEM or any other fuel management components.

I am considering parting it out and giving up as well. I wonder what I could get for a fresh 0 hour premium rebuild 951 di from SES? Ebay? I'm ready to give up just yet so:

I checked this morning and now I have 92 psi at the fuel filter outlet when tether is applied and engine is not cranked.
I blew through the return line and it is clear.
13.4v on battery
13.4 positive on each of the two fuel injectors.
On partial dis-assembly I confirmed the rear injector sprays. The front does not.
When I swap the injector plugs the front sprays but not the back.
On removal of the rail the compressor air line sprays some fuel spray when cranked. That can't be right.
off to take the rail down now.

 

[Tyman2020]

You need to put a t into the feed fuel line and read fuel pressure like that you arent regulating the system