24V Won't run

[strohlde]

2004 24V with the Marine power 5.7L

Dealer put in a new distributor and changed all fluids/filters. I put in a new battery, new alternator (dealer said it was shot) and changed the plugs.

It would fire up before the work was done but would only run in limp mode, but now after all that it'll fire up and run (rough) for about 30 seconds then just turn itself off and then not start again (still cranks...just won't start). Tried again the next day...ran for a few seconds and then turned itself off again and wouldn't start again.

Ideas? Seems like it's potentially starved for fuel? What's an easy way to check that?

I didn't gap the plugs when I threw them in...so not sure if that could be causing this. Lost my gapper.. but I'm going to go grab another today and pull them and check the gaps.

[Tanner]

What was causing the limp mode?

Wondering if they put the distributor in correctly.

[SPBFAN]

Check fuel pressure when running. If it drops off from 55 PSI or better and or does not hold steady your fuel pump needs replaced or you have a leak in the fuel system. Let us know

[strohlde]

Ya. I'm going to check the fuel pressure when I get home tonight (except running for 30 seconds might be a stretch...might be more like 10). At least start ruling things out.

Not sure what the initial cause of the limp mode was, and I'm assuming they put the distributor in correctly, as that's what I paid them for. I didn't really like the attitude I was getting from the service manager though, he couldn't seem to get me out of there fast enough. Not overly forthcoming with information and seemed to not want to deal with me, even tried to sell me a new boat. I would hope that they verified the engine ran after they completed the service but at this point I'm not sure they did.

[laserfish]

Does it have a check valve in the fuel tank that could be stuck or clogged?

[strohlde]

Does it have a check valve in the fuel tank that could be stuck or clogged?

I don't know. How do I check this? Also...is there an inline valve prior to the pump (aside from the check valve)? The service manual says to close the fuel valve at the tank prior to changing the fuel filter, just wondering if maybe they forgot to open it back up. But I suppose a pressure check should rule that out too.

[strohlde]

Alright. Bought one of those cheapo fuel pump test kits from Harbor Freight. Engine ran a bit longer this time... maybe a good 30 seconds ... anyhow the gauge pegged at 100 psi for the entire time it was running. Regulator?

It stopped itself as it does every other time and then wouldn't restart. After a few tries it starts to grind...wait a bit...then it started again real rough for about 5 seconds before stopping again. Didn't try it again.

Would the engine cut out if the pressure is too high?

Are these symptoms in line with this? or just another part to replace on my quest to a working boat

[lohe]

wow I am not %100 sure on marine, but auto EFI engines 50-60psi is what you want. The higher PSI would make it go rich/stumble/flood and die out. After it stalls out pull a spark plug out and see/smell if it is covered in fuel.

[SPBFAN]

YES

YES that is a big issue. You are focing the injectors closed. That would be a good pattern on a scope to really mess with someont that does not understand scope patterns. You need to get that fixed first. You may have injector issues aftarwards or you may not.

[strohlde]

Question is ... wouldn't this have existed before? As I've mentioned when we first put it in the water, prior to taking it to the dealer, it would start and run until I turned it off. Was there enough crap in the fuel filter before the dealer changed it to mask this problem? And aside from that...shouldn't they have started the engine and seen this? Or as I keep coming back to... I think they just swapped parts/changed fluids and never bothered starting it again. They seemed to be pissed that I was going to replace the alternator and plugs myself...vs paying to have them do it. It's unfortunate because I got several recommendations for the dealer but I just am not satisfied with the way they treated me. Going to have to find an independent guy in the Austin area.

[SPBFAN]

That is sad that this happened. I have heard nothing but good about these guys. Maybe you should give them a call and see what they say. Tell them what you found. I am sure you need a new regulator but with out being there to test it I can not say for sure. The other question is what is your engine vacuum sitting at.

[strohlde]

No idea on the engine vacuum. I'm not overly mechanical...so trying to figure this out as I go. How would I go about checking that?

I suppose I should call the service manager tomorrow and talk to him. Is it possible the return line to the fuel pump is blocked up? The cooler? Is the flow from the pump one way? Or can the fuel return back to the pump through the supply line? I suppose if it's only one way then it'd likely be the regulator as once the engine died the pressure returned to 0 indicating the fuel did leave the line via the return route? I was maybe going to pull those tomorrow and check them. Any easy way to check the regulator? Is the ECM not opening the injectors because of the high pressure? Is that why the engine is dying? I pulled one of the plugs and it was bone dry so I don't think it's flooding.

Thanks for the info. It's appreciated.

[Tanner]

Austin huh? Guess you could drive over and try and pay Tige to help you! You never know.... their customer service is pretty damn good! Might be worth a 3.5 hour drive to know it's getting done right and w/ the goal to make you happy! I'd call Harvey first though..... AFTER you call the servicing dealer first of course. Gotta give them a chance.

[strohlde]

argh. Ok...bought what I thought was a replacement for the FPR and put it in there...engine didn't start at all. So I scraped some of the gunk off the screen on the old FPR and put that back in and it started up for about a minute right at 50psi, but it still shut itself off. Also I've notice that the volt meter is reading 12v and seems to drop. I just put in a new alt and new batteries..so I'm thinking the gauge is wrong? What is going on? ARgh!

[dogbert]

I know my Merc is very sensitive to low voltage situations and will shut itself off, not sure about Marine Power. 12v is not normal. Are you sure you don't have a loose ground somewhere? I'd start by checking the alternater