Merc 240 efi won't re-start

[LesPaul]

2002 Challenger 1800, Mercury v6 240 efi, m2

I have did a search here and got some of what I think I should check.

Starts fine at the dock, runs great until I shut it off. Then it will not restart. Engine cranks, sputters a bit but will not restart. Battery good (12.3 volts), I checked the plugs, not wet or dirty. Cleaned them anyway. Primer bulb seems to be firm. Vapor separator seems fine, I can hear the pump inside, fuel drains out when screw is loosened. I guess I need to check the high pressure side. Head temp sensor? Thank you.

Seems to be related to after run hot situation

 

[Dr Honda]

Some of these engine... including mine... do not like to start hot, unless the get some good fresh air. Are you running your bilge fan for a couple minutes before starting up again?

Also... when warm, and idling... what's the RPM?


***** EDIT *****

Just notice the name.... LesPaul. But the picture is Paul Stanley? And he didn't even play Gibson. I think he used Washburn most of his career? LOL

 

[LesPaul]

Some of these engine... including mine... do not like to start hot, unless the get some good fresh air. Are you running your bilge fan for a couple minutes before starting up again?

Also... when warm, and idling... what's the RPM?


***** EDIT *****

Just notice the name.... LesPaul. But the picture is Paul Stanley? And he didn't even play Gibson. I think he used Washburn most of his career? LOL

Yes, sir. I ran the bilge fan and also had the rear compartment open (not at the same time). Plenty of fresh air, especially after the 3 mile tow back to the dock.

After I got her home I put her in the driveway and continued to try and start it, doing the things I mentioned above. Nothing. Plenty of fresh air.

Not sure what the idle RPM is (no tach), but it seem low to me. The manual says it's not adjustable.

LOL-The picture is Ace Frehley. He plays Gibson Les Pauls exclusively. Paul Sanley has used many different over the years. Early years were Gibsons (Flying V, Explorers), Flying V/Explorer knock offs. He also played Ibanez, Epiphone, Greco, and yes, Washburn. I have been told that PS only uses Les Pauls in the studio.

 

[Tim75]

Where is your flywheel cover? You have a potentially dangerous condition there.

Put pressure gage onto vst fitting. Turn key on: what is the pressure?
Turn key off: How long does it take for pressure to return to zero? If it is immediate; you may have leaking injectors causing a flooded condition- hard to restart.

Pressure should drop slowly, draining back thru vst pump.

I had my injectors cleaned/rebuilt and my 240 starts (hot or cold) in under 2 seconds

 

[Dr Honda]

Yep... what he said.


OK... I thought this was just a hard to start situation. But it sounds worse. Did it eventually restart... or is it just dead at the moment?

 

[LesPaul]

I replaced the battery and it started fine (in the drive way). I plan to take it back to the water tomorrow and see what happens. The battery that was in there was a few years old. Showed 12 volts, but dropped upon cranking.

 

[LesPaul]

Finally got a chance to take it back to the water. Ran like a champ for the 30-40 we were out. Back at the dock, shut it off and no re-start again. Just turn over. Looks like I will be testing the injectors tomorrow, like Tim75 suggested. Do I need to special pressure gage to test the VST? I have read where a regular tire gage will work.

TIM75-Not sure what you mean where"s my flywheel cover?

 

[Dr Honda]

I don't know what he means either. (Flywheel cover)

Yes, you can use a tire gauge. But I do recommend one that locks in, opposed to a push on style. But with your description... I'm guessing you are going to have leaky injectors.

 

[LesPaul]

Thank you, Dr.
I did some research last night, but I am unable to find my engine serial number listed anywhere.
OE396412. Where do most people here order their parts from? If that is all it is (leaky injectors) I think I will be happy. Fingers crossed. Hopefully after work today I can get out and check the pressure drop. It's just been so blistering hot here in the south. Yesterday almost killed me working on the trim plate.

 

[Dr Honda]

Merc parts, I will do a quick look on ebay. Seems like you can find stuff at a good price. (but only OEM and a reputable seller) If I just need it quick... I get it from boats.net. They normally have stuff in stock, and discount some from retail.

What part of the world you in? I'm on biz in New Orleans... and it's hot !

 

[LesPaul]

I'm in New Orleans, strangely enough. LOL. yes, it has been very hot lately.

I read on a different post that bad o rings wouldn't cause leaking. So what will cause them to leak?

 

[Dr Honda]

Being 17 years old... lots of vibration in a 2-stroke... and not originally meant for alcohol based fuels. BUT... it's not normally the O-rings, unless it's been apart. It's normally that they leak from the tip, and lightly flood the engine.

 

[Tim75]

Flywheel cover-
Plastic, molded, goes on top of flywheel to minimize injury risk.

 

[LesPaul]

Tim75-Oh ok. I guess I just didn't understand the question. It's the round cover. Not rectangle.

 

[LesPaul]

Being 17 years old... lots of vibration in a 2-stroke... and not originally meant for alcohol based fuels. BUT... it's not normally the O-rings, unless it's been apart. It's normally that they leak from the tip, and lightly flood the engine.

Dr. Honda, how do I fix it? Do a pressure test first and go from there?

 

[Dr Honda]

Generally... take them out, and hand them over to a fuel injection shop. Honestly... it's not very expensive for a shop to do a full service on them. Normally under $100 for all 6.

 

[LesPaul]

Well yesterday I bought a fuel system pressure tester for $50 (pretty sure I will only use it once).
Attached it to the schrader valve next the VST. Key on roughly 36-38 psi. Key off and it dropped very slowly. After about 8 minutes it dropped to about 20 psi and never went below that.
At this point I am pretty confident that the injectors are not leaking.

Should I start looking at the air temp sensor and/or the port temp sensor?

Is there any way to bypass the air temp sensor for testing purposes?

 

[Dr Honda]

I guess I need to check the pressure on my engine, since it's running properly, as a baseline for an injecotor bleed-down.

As far as bypassing the 2 temp sensors.... um.... yes. I think you can. In the manual, it list the resistance at different temps. SO... you can just put the proper value resistor in-line, and take the sensor out.

But it's easy enough to check them with a meter also.

 

[LesPaul]

Thank you Dr. Yes, I saw the values for checking.

 

[LesPaul]

Dr. Honda, when are you leaving New Orleans? I'd love to buy you a beer.

Let me start by saying that I am NOT the sharpest knife with regards to electricity, resistance, ohms, ect. Everyone is good at something, but no one is good at everything. So with that being said, I pulled the sensor. set my Fluke multimeter to K ohms. I have an initial reading of 18k and goes up when I place the sensor in ice water. I believe that my values are way high and out of spec, as per the graph. I think the sensor is bad. I have attached a screen shot of the testing procedure and readings from the manual.

Any help would be greatly appreciated. My wife is crawling up my azz to get this boat running. lol

 

[Dr Honda]

18K ohms at room temp? And it's been hot here. Should be around 5K SO... yes... that seems off.

I'm here until Sat morning. I have to get to work at the moment, but I'll PM later.

 

[LesPaul]

Ordered the temp sensor. Should be here early next week. Hopefully this will fix the problem. Finger's crossed.

 

[LesPaul]

New temp sensor arrived today. I did a side by side ohms test. New on read 8.68 k ohms, old one 13.38 k ohms at room temp. So I do think the old one is bad, I just hope it resolves my no hot start issue.

 

[Dr Honda]

Yep... it wasn't happy. Keep us up to date when you get it out on the water.

 

[LesPaul]

Will do. Fingers crossed.