Engine turns over but no purr

[xintersecty]

OK, I went down to the dock to fix a few things. Mostly my Navigation lights, radio, and Intake Grate thingy. Now I have lights, radio and a working intake grate, but the motor does not start. 2006 Challenger 180 with super charger.

So here what has been done.

Check the connection at the fuse block near the motor. All fuses are good.
The fuel pump does work and pressurizes the system. (At least voltage check, did not do the pressure check).
I have measured the voltage at the spark plug coils (ranges from 11.5 - 11.98 volts)
I replaced the spark plugs with new ones.

I get a good ECM beep code when putting the DESS key on the post.
The motor turns over well but does not catch.

I don't have a BUDDs system, so what can be done with voltmeter and poking?
Any advice from there?

 

[chlarson23]

take the battery and get it load tested at your local auto parts store. on occasion batteries can be known to retain volts but lose amps. Amps crank and start motor and it's an easy check if you can't find anything else.

 

[Sportster-2001-951C-Stock]

Maybe you need to put a tiger in the tank? Seems you've done a good bit of checking and if the coils are being pulsed by the MPEM then there should be fire in the hole so I dunno what it could be, maybe no fuel check fur sparking. sorry but it sounded at 1st like the tiger got loose again!

 

[xintersecty]

Thanks, I will pull the battery and take it Advance. I bought the battery new this may. It has been turning the motor over well. And besides and after a bunch of starts, it's going to need charging.

 

[xintersecty]

Maybe that's the problem. The first tank of gas in May was Exxon and I have been filling up from BP since then. Finally the tiger has left the boat. Well I have started to look for a inline spark tester that I can use without igniting the bilge to really see if I am generating spark from the coils. Otherwise it's the injectors.

 

[Sportster-2001-951C-Stock]

Might find some liquid feline go juice(the flammable type) and drop some in the cylinders to see if she pops at all.

 

[xintersecty]

Right now I have the fuel pump out of the boat waiting on a replacement pump and two filters. This might work. Not sure. The inside filter did have some loose gunk that might have interfere with fuel delivery.

 

[xintersecty]

Well I pulled the fuel pump and replaced it. http://www.seadooforum.com/showthread.php?66031-Fuel-Pump-Purchase It almost started it. As a lame pressure test, I did open the fuel tank vent. Put the key on the boat, the fuel pump started shut down, then the system gave a long beep and would not start (turn over). So it can tell if the fuel is pressurized or not to allow the starter to engage.

I took the battery out and charged it.

I am getting frustrated as this should be an easy fix. Tonight maybe a spark tester?

Should I buy the candoo software? It's a lot of money.

 

[xintersecty]

oh yeah, I have been slammed with flooding at my dock. I live on creek feeding into Lake Keowee. I spent like five hours just knocking crap loose.

 

[Sportster-2001-951C-Stock]

Do you have the electrical schematic? As far as I know, I don't think the MPEM knows what the fuel pressure is, it doesn't know if there's too much or too little (there is no fuel pressure sensor on the electrical schematic?). The MPEM should turn on the fuel pump briefly once it reads the lanyard successfully to pressurize the fuel system, right?. That's all it does in preparation for the start button press. Once the start button is pressed the MPEM turns the fuel pump back on, cranks the motor, fires the ignition, fires the injectors, and turns on the gauges?

If the MPEM doesn't see a signal from all the sensors(crankshaft position sensor, throttle position sensor, air temperature sensor, exhaust temperature sensor, intake manifold vacuum pressure sensor, etc.) it may not fire the injectors and may not fire the plugs, it also may not crank the engine? I don't have the schematic, but I believe there is no fuel pressure sensor?

Open throttle full open and see if the MPEM will crank the engine(it should not start, there will be no fuel or spark if MPEM thinks throttle is full open, this is "flooded mode"). Always be prepared if engine does happen to start unexpectedly, safety is always important.

Then I would check for spark. If there is none, then there could also be no fuel injection for the same reason, could be any of the sensors are not present. For example, if the throttle position sensor is at maximum the MPEM thinks the throttle is full open and goes into "flooded mode" then when the start button is pressed, the MPEM will just engage the starter and crank the engine without ignition or fuel.

When you press the start button with lanyard removed, doesn't the MPEM turn on the gauges? Check for this as well, before placing the lanyard on the post.

 

[xintersecty]

14 pieces of paper later and a lot of scotch tape, I now have a set of schematics. I like your diagnostic suggestions without using software.

The Gauges do turn on. I am going to get a better spark tester on the way home.

 

[pwgsx]

The CanDoo system is a bit pricey but I love it! Best money ever spent. Unless your throwing a code though, I don't know if it would help you.

 

[xintersecty]

The CanDoo system is a bit pricey but I love it! Best money ever spent. Unless your throwing a code though, I don't know if it would help you.

How would I know the system is throwing a code. Should I get a different beep code or would the 4 light cluster gauge show a different light?

Here are last night's summary of what I have learned:
1) I used a spark tester and each coil is indicating a spark to the spark plug
2) I lifted the fuel rail and injectors out and could see each injector misting fuel.

I am wondering if I have weak spark coming out of the spark plugs. The last time I measured voltage, each circuit was slightly below 12 volts. So I am going to start at the battery and chase down the wires to each plug and make sure I am getting 12 volts.

 

[Sportster-2001-951C-Stock]

How would I know the system is throwing a code. Should I get a different beep code or would the 4 light cluster gauge show a different light?

Here are last night's summary of what I have learned:
1) I used a spark tester and each coil is indicating a spark to the spark plug
2) I lifted the fuel rail and injectors out and could see each injector misting fuel.

I am wondering if I have weak spark coming out of the spark plugs. The last time I measured voltage, each circuit was slightly below 12 volts. So I am going to start at the battery and chase down the wires to each plug and make sure I am getting 12 volts.

Another way to see if the MPEM is firing the fuel injectors is to connect a "NOID" light in place of the injector, I forgot to mention this earlier.

But, it sounds as if you have both fuel and spark, so the engine should start. Of course battery voltage cannot drop below an acceptable level while cranking, probably less than 10.5Volts is too low, hopefully you see 11V.

You might try opening the throttle slightly while attempting to start, say lass than 1/2 throttle, that might help.

So, I'm not understanding why it won't run, fuel+spark+compression is all that's needed. Might try to squirt a tablespoon of gasoline in each cylinder through the spark plug holes for a tad more fuel, but you shouldn't have to.

Some skis have engine code display on the instrument cluster head, I believe.

As far as engine codes go for mine, these skis all have a basic self diagnostic that might reveal if the MPEM detects something's wrong but since it's firing the injectors and plugs, the MPEM seems happy enough to at least start the engine. The diagnostic mode on my ski MPEM is entered by removing the lanyard and pressing the start buttom five times. At this point the MPEM should give two beeps telling you to place the lanyard on the post, then press the start button once more to retrieve the code.

This(attachment) is the older DI engine MPEM self diagnostic, your shop manual should have a section similar to this. I think most all of them are enabled the same way, and yours probably has an extended set of "signals" or codes than this table shows.

Okay, so if you get it running by something I may have suggested, then you have to promise you will go riding for at least 15~20 minutes. That's where I'll be this afternoon, so see ya out there!

 

[xintersecty]

Okay, so if you get it running by something I may have suggested, then you have to promise you will go riding for at least 15~20 minutes. That's where I'll be this afternoon, so see ya out there!

OMG you must be kidding if I get running I am not leaving the damn lake! LOL!

Just measured the battery with boat OFF and I am getting 11.8 volts. Not happy I am taking to place of purchase for a battery check.

spark fuel compression.....need that purr! Maybe not enough omph in the spark? I will find out!

 

[xintersecty]

You might try opening the throttle slightly while attempting to start, say lass than 1/2 throttle, that might help.

I tested the battery and took to Advance, they tested and charged it up, tested and declared it bad. So I got a new battery. At least it reads 12 volts. I went back to the boat, no luck, it almost caught. Gave it a break and then tried the 1/2 throttle suggestion and it fired up.

It runs very very rough. While running I get a chkeng light. So I guess I will be buying Candoo. When I back the throttle back down it shuts down. [MENTION=65307]Sportster-2001-951C-Stock[/MENTION] Thanks for your suggestion.

I pulled the intake off the supercharger. Can I turn the blades by hand?

So we have fire and fire. I guess I can do a compression check to make sure things are good there. So the problem might be air?

 

[Coastiejoe]

I tested the battery and took to Advance, they tested and charged it up, tested and declared it bad. So I got a new battery. At least it reads 12 volts. I went back to the boat, no luck, it almost caught. Gave it a break and then tried the 1/2 throttle suggestion and it fired up.

It runs very very rough. While running I get a chkeng light. So I guess I will be buying Candoo. When I back the throttle back down it shuts down. [MENTION=65307]Sportster-2001-951C-Stock[/MENTION] Thanks for your suggestion.

I pulled the intake off the supercharger. Can I turn the blades by hand?

So we have fire and fire. I guess I can do a compression check to make sure things are good there. So the problem might be air?

The SC should be very difficult but doable to turn it over by hand. If it spins easily it needs rebuilt. That said, it would not be the reason for not starting, especially if it spins easily. You normally lose about 15 MPH when they fail, (it is a good sign it is bad or a hose has come off or is cracked).

 

[Sportster-2001-951C-Stock]

If it runs but rough, I would change the plugs if you haven't already. Don't run it around the lake though if it's not running correctly, no point in that. Also, you changed the fuel pump, that could be the(new) problem(low fuel pressure) if it's not the right fuel pump!

Could be a clogged fuel injector also or something else of course, maybe you can feel the spark plugs for heat and find one dead cylinder that way(1 stone cold plug and two warm plugs) if you run it for a bit but I don't like to run any engine very long except for troubleshooting, if it's not running correctly.

Any battery is in need of charge or is bad if it measures less than 12.5 volts! The cranking voltage really shouldn't be much less than one volt lower, so about 11.5V

I bet your chkeng light is probably a misfire code, the MPEM can likely detect a misfiring cylinder by using the crankshaft position sensor.

 

[xintersecty]

I have a lightly used set of fuel injectors coming from EBAY arrive on Thursday. I can replace the injectors and see if that eliminates the starting issue at low throttle.

Since I have pulled the fuel rail, any advice on changing the fuel injectors? Once I get mine out, I plan to send them out to get reconditioned so I will have a set ready to go.

 

[Sportster-2001-951C-Stock]

I'm not sure how you determined the fuel injectors are at fault without measuring fuel pressure first, but if the injectors aren't operating properly then it makes me think the fuel filter is most likely full of junk.

So, I'd replace the fuel filter too, if you haven't already. If fuel pressure is incorrect, could be fuel pump or fuel pressure regulator.

 

[pwgsx]

The CanDoo will read the engine codes and tell you what they are and if active or occurred. They will describe what they are too but usually you will need to look in the manual for a better description. You can also check high low voltage, temps, and a bunch of other things when its running. I kinda have the same issue, it starts but idles rough on one engine. I reset the TPS and it helped a little. Maybe its the idle valve?

 

[Sportster-2001-951C-Stock]

The CanDoo will read the engine codes and tell you what they are and if active or occurred. They will describe what they are too but usually you will need to look in the manual for a better description. You can also check high low voltage, temps, and a bunch of other things when its running. I kinda have the same issue, it starts but idles rough on one engine. I reset the TPS and it helped a little. Maybe its the idle valve?

I've replaced quite a few idle valves on fuel injected engines, Ford/GM/Mercruisers, not familiar with Rotax idle valve strategy. Idle tends to not be at the correct speed, either too low or often too high depending on how the valve is constructed and how it fails. Roughness though, isn't what I'd expect unless the speed was below target(idling too slow). Inconsistent idle speed can also be a symptom.

Maybe the Rotax fuel filters are inadequate for stopping dirt/trash from entering the injector rail? Since the pump probably pumps a large volume of fuel and the fuel is constantly being circulated through the pressure regulator then depending on where/how the pressure regulator is plumbed, the filter should really be polishing the fuel in the process so anything leaving the tank is trapped in the filter until it isn't, once the filter loads up with solids the trash then could find it's way into the injector rail and pressure regulator as well.

Too low of fuel pressure due to a regulator plugged with trash would definitely cause a hard starting issue due to lack of fuel.

This is why it's wise to invest a few bucks into a proper fuel pressure gauge.

 

[xintersecty]

Too low of fuel pressure due to a regulator plugged with trash would definitely cause a hard starting issue due to lack of fuel.

This is why it's wise to invest a few bucks into a proper fuel pressure gauge.

When I replaced the fuel filters are part of the fuel pump replacement, the inside filter was looking a little gunky. It's been rumored that that filter degrade causing issues. I looked at a few gauges online and that will be my next automotive purchase. Of course there is not good place to tap into the system. I looked at harbor freight and they have a gauge that you put a tap into the line with a T-fitting.

 

[Sportster-2001-951C-Stock]

When I replaced the fuel filters are part of the fuel pump replacement, the inside filter was looking a little gunky. It's been rumored that that filter degrade causing issues. I looked at a few gauges online and that will be my next automotive purchase. Of course there is not good place to tap into the system. I looked at harbor freight and they have a gauge that you put a tap into the line with a T-fitting.

Okay, good ou're looking into testing the fuel pressure. It's really easy to throw a lot of money in parts at these things if you don't have a minimum of test equipment, a candoo won't tell you if a particular injector is clogged or if fuel pressure is too low, it will detect these as a misfire.

So I'd rather have a fuel pressure gauge than a code reader, especially if the fuel system appears to be malfunctioning. Code readers can lead you to electrical problems though, such as "Out of spec throttle position sensor" type codes.

Just the list of possible codes itself is worth looking at for clues of potential problems, without even having the candoo. Say for instance the idle air control soleniod/motor was sticking, you can suspect this part if your idle is varying intermittently by a few hundred RPM's and inconsistent, or by watching the MPEM control realtime position/code using candoo while the MPEM tries to juggle the sticking idle control the value goes to some extreme but the engine idle speed doesn't respond.

So yeah, the candoo can be useful but it's not the be-all end-all answer to every problem under the sun. If your idle is rough, the candoo might not be able to tell you the real reason why(root cause), many of the issues require some technique to isolate.

A nice feature imbeded into a candoo type system would be to take a fingerprint of a system that's running properly and comparing it to a system that's got a bugaboo phenomenon suce as a rough idle, the comparison can lead to a resolution.

For instance, I had a customer bring his mercruiser up to the fuel dock one day, he had just splashed his boat the first time that year and it was a nice spring day and his friends had come down for a visit but his dang boat was sounding an alarm every time he tried to pull a skier.

Well, I connected our code reader to his boat and found the code for the knock sensor was causing the beeper and limp mode so I looked down into the bilge and found his knock sensor was hanging on a loose bolt in the side of the block and rattling around. Obviously whomever had winterized his boat had forgotten to tighten the bolt that fastened the knock sensor into the block drain hole into which it was mounted. They had taken it loose in order to drain the water from the block and forgot to tighten it.

Our code reader saved that guy's day, he was really happy we had one and could read his code! We sent him on his way, haven't seen him since.

 

[Sportster-2001-951C-Stock]

the inside filter was looking a little gunky.

Yep, if the fuel filter stops doing it's job then a big wad of trash(it's full of trash!) can pass through and contaminate you fuel rail and the trash can not only clog your injectors but it can also wedge into the fuel pressure regulator valve and cause it to stick open, which will cause low fuel pressure.

Take that fuel filter and fill it with fuel, shake it around vigorously to agitate the contents then pour that into a cup from the inlet side of the filter(where all the trash gets trapped) and you'll be amazed at how much trash comes out. Note that a really good fuel filter can have enough filter media surface area to cover a football field but I doubt we'll find many of those in our boats though, these things should really be changed periodically.