EFI 5.7 Stalling with hard/no start... Suggestions please

obsessive

obsessive

New Member
Jun 11, 2007
151
Hampton, IL
Boat Info
99' 240DA
Engines
5.7L TBI - 260HP
Well...

Not too good of a start on Labor Day weekend. Yesterday afternoon, my wife and I decided to go out for a little dinner cruise, gearing up for today and Monday (during which we were having people out).

As we were cruising along at 1000rpm's, the engine lost power and regained it. I instantly looked at the battery voltage, oil pressure, temperature, and depth (to make sure I didn't hit ground) and saw nothing wrong, then about 10 seconds later it just died.

I was able to get it restarted, but it would only run for a little bit (<30 seconds). When it did run, it ran fine, no stuttering, hesistation, rough idle or anything like that until it just dies. While it is running, it has good power (I was able to get up on plane once before it died, and had no trouble doing so).

I opened the engine hatch and inspected the spark arrestor, fuses, breakers, ECU plugs (unplugged and reseated them), and about every harness I could think of. Both injectors were firing, but then something odd happened...

Now, sometimes when the key is cycled to the on position, instead of hearing the fuel pump cycle for a couple of seconds and turn off WITHOUT the injectors firing, the injectors will seemingly ramdomly fire and the fuel pump will continiously run.

Also, when it does this, the two beeps I usually get when I cycle the key to the on position (warning buzzer test sequence), it doesn't make any noise at all. It almost appears that the ECU 'thinks' the engine is running, and is attempting to fire the injectors. I realize that the ECU depends on the pick-up in the distributor to determine RPM, firing of injectors, and ignition spark and timing. Could this sensor be taking a dump and sending intermittent pulses to the ECU tricking it into thinking that the engine is actually running at some odd RPM, instead of knowing that it is getting ready to start?

I'm going to go and test it, as I've got a service manual from a friend today. I'll take my meter down there and check ECU ground, injector power, power to the distributor sensor, output of sensor, sensor resistance, etc.

I guess my question is... Is this something common that has a 'magic bullet' fix because it happens commonly, or at least am I on the right track?

Thanks in advance,

Eric
 
The only thing you didn't mention is the fuel filter. It could be clogged or you could have water in the fuel. Places like West Marine will have one on a Sunday if you want to buy it today. I would change that out as well and if that doesn't do it then you probably are going to need a Merc Technician with a scanner to plug into your ECM to diagnose what is going on.
 
Unfortunately, there isn't a West Marine around here... :(

But, I did use my meter on the pick-up coil in the distributor and found that the resistance sometimes is in the MEGOHMS (super high), and it's supposed to not be below 100 ohms, but they don't give a maximum resistance, but since it's a coil of wire in there, it should'nt be megohms.

When I say 'sometimes' in the megohms, it fluxuates, so I can assume that it's a possible break in the coil or moisture intrusion.

I also found a service bulliten from Mercruiser for 99' engines in my serial number range that states that the pick-up in the Mercury Marine distributor (like I have) experienced a high failure rate and they had reqorked models. It was only a bulliten and unless they failed, they weren't replaced.

I assume that mine is original, as the leads are partially spraypainted black from the factory when the entire engine was painted, if it was a replacement, the leads should be clean with no paint (I would assume).

Thanks for the reply!

Eric
 
Obsessive,

I've just experienced same sort of issue. But if I let it cool for an hour or more it will run fine for about 6-7 minutes then starts missing and finally quits. Then unable to restart until it cools again. I've replaced water/fuel filter, plug and coil wires, coil, rotor, cap, and plugs. Mine's a 99 engine. Could you let me know the serial #'s of the effected engines and what fixes your problem?

Thanks and good luck

Tom
 
We had similar symptoms and it turned out to be the fuel filter.

Boat would run for a few minutes, including up on plane, then lose power and idle very roughly for a few seconds, then quit. After a few minutes, it would start again, run for a few minutes, and quit. After doing that a few times, it finally wouldn't restart.

Once the filter was replaced it ran fine.
 
Eric,

The only time I do not get the startup alarm is when the kill switch (where the lanyard connects) is open, or partially open. Maybe yours has a bad connection... Just thought I'd toss that out there...

Michael
 
Thanks for all the suggestions, guys!

I did replace the pick-up sensor in the distributor and she runs like a champ, now.

Tom, the part is around $58 bucks and my dealer had it in stock. I took the opportunity to do a cap and rotor too (you may damage the rotor getting it off, so it is a good idea to replace it anyway, its $11). Also, the old pick-up is completely exposed (except for a blow of silicone), and the new one is encased and sealed. Also, the new one has a seperate ground lug (I used the manifold ECU mount stud) to eliminate failures due to voltage spikes (I assume this is common from seeing the service bulletins).

I haven't taken her to sea trials yet, but I couldn't even get her to run 30 seconds two days ago (agter getting pulled back in to marina).

She ran for over an hour tonight in 90 degree temps (hotter than this Sat. when she died) with no issues... Revs up smooth.

Sea trials to come (maybe tomorrow night).

Eric
 
You must log in or register to reply here.

Forum statistics

Threads
113,253
Messages
1,429,373
Members
61,133
Latest member
Willbeckett
Back
Top