Fuel Injectors Cleaned

[Bozboat]

Fuel injector wiring is in the same order as JustGary's post.

Fuel pressure gauge will be here tomorrow.

I am suspicious of the coil. Would a weak coil limit RPMs and then a failing coil cause the engine to die under load?

[Bozboat]

UPDATE working thru multiple problems

Fuel pressure at key up was 38 need 48, suspect fuel pump is weak and need to test psi at WOT.

At this point I'm still thinking I have an ignition problem based on the way the boat cuts off rather than starves out. I replaced the coil, also noticed that the number 8 spark plug wire was off at the distributor, I have no idea how long it was off, want to believe I knocked it off replacing the coil. Run it on the Hose for 45 mins, sounds great. head to lake for test run. Boat starts and runs great, ran 3500 rpm 15 mins to the smooth water, all good, do a WOT test and it hits 3900 rpm and cuts off just like I yanked the kill switch. Discover the Ignition control module is red hot. Let it cool, crank it and get 150 yards and boat dies. ICM red hot again and no spark from plug wires. Throw out box anchor. Call son, he delivers a ICM from my parts box via ride from jet ski rental guy. Swap out ICM and boat fires up immediately. Resume test, 3800 rpms or so and that's it. This time is seems like it is starving for fuel. Fuel pressure at WOT is 25, need 43-45. Return to base, swap the pesky small low pressure fuel filter in trunk, old one is hard to blow through, back to lake, launch boat, starts and I back off trailer. Boat dies like it ran out of gas. Fuel pump whines and whines and can't make more than 5 psi. Fuel pump is really hot to the touch. Back on trailer and return to base. It appears to be time for a new fuel pump. The fuel pump has been loud for awhile, I checked the screen at start of summer. I think the engine runs better with the rebuilt injectors, I think the coil going bad fried the ICM fried or the coil was fine and the ICM bad but I think that this was a separate event unrelated to the fuel injector cleaning and separate from the fuel pressure problems. I will get a new fuel pump on next week and try that. 3 years on a fuel pump seems pretty lame, but no point whining about it.

Any one else have any theories?

Cool video of pressure gauge

Edited August 12, 2015 by Bozboat

[Slayer]

Wow!

I'm guessing fuel pump with all else you've done. I would think you would have found the gremlin.

[shawndoggy]

ugh! gremlins!

Love the story about the jet ski rental parts delivery... and that it didn't slow down your troubleshooting.

[Bozboat]

ugh! gremlins!

Love the story about the jet ski rental parts delivery... and that it didn't slow down your troubleshooting.

I wish I could say asking the jet ski rental dude for parts delivery was my idea, but it wasn't.

[Lance B. Johnson]

I've used a place called fuel injection connection with good luck. Same deal ship 'em off and get them back in a few days.

[justgary]

I love the fuel gauge video. You didn't realize you were buying the new rubber kind, I guess.

What are the odds that you take your fuel system apart and then immediately have spark issues? It is possible you dislodged some crud, or maybe blew the module with the loose wire. That makes more sense to me than a random failure.

Now we need to ponder whether cleaning the injectors can cause the pump to fail. I've heard of blowing a radiator hose after a water pump change, so maybe the pump got jealous of the clean injectors.

[Bozboat]

I love the fuel gauge video. You didn't realize you were buying the new rubber kind, I guess.

What are the odds that you take your fuel system apart and then immediately have spark issues? It is possible you dislodged some crud, or maybe blew the module with the loose wire. That makes more sense to me than a random failure.

Now we need to ponder whether cleaning the injectors can cause the pump to fail. I've heard of blowing a radiator hose after a water pump change, so maybe the pump got jealous of the clean injectors.

One other puzzle piece, I got lazy and didn't replace the small low pressure fuel filter this Spring. Replaced the Hp fuel filter. I have noticed whining from the fuel pump this season so maybe that was due to a restricted low pressure fuel filter. I agree that coincidence is difficult to accept, but idk.

[RTS]

Absolutely a clogged filter will make that pump whine and squeal. They are lubricated by the fuel. MIne would always squeal for a brief, brief moment until it caught prime....like half or quarter of a second first key on of the day and after a prolonged period of floating in the lake.

Good news is that you fuel pressure issue might be as simple as a clogged/clogging filter. Bad news is starving it for fuel for a while may have decreased its expected life.

I could never hear my fuel pump (except for aforementioned brief squeal when priming) unless the pump was going bad....I'm talking about with the engine hatch closed and engine running. If you can hear the whine outside the clamshell, that's not good.

[Pistol Pete]

What about fuel pressure regulator?

Is there one?

[Bozboat]

What about fuel pressure regulator?

Is there one?

There is a fuel pressure regulator mounted near the pump, it is three years old. I understood from Paul at Bakes that high pressure means a bad regulator and low pressure means a bad pump.

[Pistol Pete]

Can you grab me a pic. of it?

My memory is starting to fail.

Is it vacuum regulated?

[Bozboat]

Can you grab me a pic. of it?

My memory is starting to fail.

Is it vacuum regulated?

This is mounted behind the high pressure filter on the back of the block (DD viewpoint)

Vacuum line goes to base of air intake

Edited August 13, 2015 by Bozboat

[Sixball]

What about the oil pressure sender to the ECM. Should be two, one is the gage PSI the other is the sender to the ECM. The unit sending to the ECM will shut down fuel pump if it not seeing fuel pressure. You could try removing it and washing it out and reinstall. I have seen this twice. The first time I did much the same as you and still could not get the boat to run. Sometimes it was good other times it would backfire and die. Both down near your oil filter.

[Bozboat]

http://www.bakesonline.com/detail.aspx?ID=1678

[Pistol Pete]

You need a vac. guage "T"'d into that line.

Do you know how those work?

At idle, you should have your "lowest" fuel pressure ~45 psi? (I don't know, don't have the book) That means you have max. vac. to the F/P regulator ~30 in/merc.

At WOT or, next to no vac avail. to the F/P regulator you should have max fuel pressure ~50-55 psi? (I don't know, don't have the book)

At idle, if you pull off the vac. line to the F/P reg. (and cap it) you should get immediate max fuel pressure and vice versa when you re-connect.

[Bozboat]

What about the oil pressure sender to the ECM. Should be two, one is the gage PSI the other is the sender to the ECM. The unit sending to the ECM will shut down fuel pump if it not seeing fuel pressure. You could try removing it and washing it out and reinstall. I have seen this twice. The first time I did much the same as you and still could not get the boat to run. Sometimes it was good other times it would backfire and die. Both down near your oil filter.

When you say shutdown do you mean it turns off the pump? Last test pump was trying to prime at key up but not making any pressure on fuel pressure gauge. Fuel pump was hot to touch. Last WOT test I was getting 25 psi on gauge but still able to run 3500rpms and sound good. Curious how ECM would shudder fuel pump without cutting power?

[Sixball]

Ya I would think it should shut down. Don't think it would change pressure.

[Bozboat]

You need a vac. guage "T"'d into that line.

Do you know how those work?

At idle, you should have your "lowest" fuel pressure ~45 psi? (I don't know, don't have the book) That means you have max. vac. to the F/P regulator ~30 in/merc.

At WOT or, next to no vac avail. to the F/P regulator you should have max fuel pressure ~50-55 psi? (I don't know, don't have the book)

At idle, if you pull off the vac. line to the F/P reg. (and cap it) you should get immediate max fuel pressure and vice versa when you re-connect.

Chart calls for 43-45 at key up, 35-38 at idle, 43-45 at WOT

I will look for my vacuum gauge and check this. Last try I couldn't get any Fuel pressure although the pump was trying. So unless function is restored when the pump cools off I may not be able to get pass key up test

[Bozboat]

Ya I would think it should shut down. Don't think it would change pressure.

That is an interesting connection between oil pressure sender and fuel pump. Thanks

[23LSVOwner]

There is a fuel pressure regulator mounted near the pump, it is three years old. I understood from Paul at Bakes that high pressure means a bad regulator and low pressure means a bad pump.

A bad regular can result in low pressure as well.

[Sethro]

Hey Bozboat, how are things going with your fuel issue?

[Bozboat]

New Fuel pump installed

Fuel pressure on spec at key up, idle, and at WOT

Engine sounds are deep and soulful, better than ever

WOT hit 5200 rpm and 46 mph with GPS speedo

I may change out the strut bushings this winter and re-align

But overall I'm good.

[shawndoggy]

*** yes!

[Levi900RR]

Awesome!