8.1 Fuel Pressure
- Thread starter Tacoma290
- Start date
paulswagelock
Well-Known Member
Sorry for the delay - yes this is it.
Tacoma290
Active Member
Update:
I ordered new top cap and pump kits from S & J Complete Marine: https://www.sjcompletefuelinjectionservices.com/
The top cap has no paint on it (just matte anodized), so this is an upgrade from the factory version; One less thing for me to worry about in the future. I need to send the old pumps back for a core credit. I believe I took the last two assemblies that he had, but he is sourcing more at this time. Jack is a great guy to deal with; he answered the phone on his day off.
Here is one of the pump pairs I removed:
Here is the debris in the bottom of the housing after pulling the pumps This was the 'cleaner' of the two:
Of course one of the bolts sheared. We have a great local guy who added heat to the inside of the housing, and we worked the bolt out. I ran a tap in to clean up the threads, and hit the threads with compressed air. I am using anti-seize on re-assembly with all the fasters to this housing to avoid having this problem again (including the filter cap bolts).
Here is the shocking amount of debris in a standard coffee filter. This is between the two pumps. I am seeing why the low pressure pump was having problems getting a prime:
And here is the inside of the housing cleaned up:
The inside water side of the pump assembly was completely fouled. I connected a garden hose in hopes of simply back flushing. No go. What did work was a 30 min soaking in Barnacle Buster. I set the pump on its end, filled both ports with Barnacle Buster. You could see and hear the stuff breaking down the thick black deposits. You could smell it too...
I now realize that one reason for the salt buildup is that here in the Pacific NW, I don't need to winterize. I do an annual flush out the water system, but did not think to do a flush of just these guys (there is a bypass valve as plumbed by the factory that means I really did not get much fresh water to these guys). Directly flushing these pumps at least annually will now be on my preventative maintenance list. Anyway, after a soak I dumped the nasty, smelly stew from the housings, and connected to a garden hose, and success. I did a second and third soaks and flushes for good measure.
So the last item I am working on is the stupid blue plugs. Since I never need to winterize here, I never have needed to use the blue plugs. One snapped as I moved it from my bench to my tote. I picked the shattered plastic debris as best as I could, then cleaned the threads with a 1/2"-13 tap. I think I will simply replace them with new for today, but I would rather upgrade them to a less delicate item. Using a hollow plug does not seem like a great idea. I will try to stop by a local fastener company, or may look into the Hardin stainless. Any better ideas to upgrade the blue plugs?
I ordered new top cap and pump kits from S & J Complete Marine: https://www.sjcompletefuelinjectionservices.com/
The top cap has no paint on it (just matte anodized), so this is an upgrade from the factory version; One less thing for me to worry about in the future. I need to send the old pumps back for a core credit. I believe I took the last two assemblies that he had, but he is sourcing more at this time. Jack is a great guy to deal with; he answered the phone on his day off.
Here is one of the pump pairs I removed:
Here is the debris in the bottom of the housing after pulling the pumps This was the 'cleaner' of the two:
Of course one of the bolts sheared. We have a great local guy who added heat to the inside of the housing, and we worked the bolt out. I ran a tap in to clean up the threads, and hit the threads with compressed air. I am using anti-seize on re-assembly with all the fasters to this housing to avoid having this problem again (including the filter cap bolts).
Here is the shocking amount of debris in a standard coffee filter. This is between the two pumps. I am seeing why the low pressure pump was having problems getting a prime:
And here is the inside of the housing cleaned up:
The inside water side of the pump assembly was completely fouled. I connected a garden hose in hopes of simply back flushing. No go. What did work was a 30 min soaking in Barnacle Buster. I set the pump on its end, filled both ports with Barnacle Buster. You could see and hear the stuff breaking down the thick black deposits. You could smell it too...
I now realize that one reason for the salt buildup is that here in the Pacific NW, I don't need to winterize. I do an annual flush out the water system, but did not think to do a flush of just these guys (there is a bypass valve as plumbed by the factory that means I really did not get much fresh water to these guys). Directly flushing these pumps at least annually will now be on my preventative maintenance list. Anyway, after a soak I dumped the nasty, smelly stew from the housings, and connected to a garden hose, and success. I did a second and third soaks and flushes for good measure.
So the last item I am working on is the stupid blue plugs. Since I never need to winterize here, I never have needed to use the blue plugs. One snapped as I moved it from my bench to my tote. I picked the shattered plastic debris as best as I could, then cleaned the threads with a 1/2"-13 tap. I think I will simply replace them with new for today, but I would rather upgrade them to a less delicate item. Using a hollow plug does not seem like a great idea. I will try to stop by a local fastener company, or may look into the Hardin stainless. Any better ideas to upgrade the blue plugs?
scoflaw
Well-Known Member
- Aug 10, 2011
- 6,395
- Boat Info
- 1999 Powerquest legend 260 sx 502 mag
2005 Baja 242 islander 496
- Engines
- 502 mpi Bravo 1
496 mag B1
What is the source of the black stuff in the filter?
Tacoma290
Active Member
Paint coming off the bottom of the top cap assembly. The previous owner claimed he had it the cool fuel 3 replaced under the factory replacement program. That doesn't appear to be correct, or the replacement was not good.
If you look at the top picture, the shoulders that support the low pressure fuel pump are sluffing off paint. Also missing a little under the pressure regulator, but the regulator was clean.
If you look at the top picture, the shoulders that support the low pressure fuel pump are sluffing off paint. Also missing a little under the pressure regulator, but the regulator was clean.
Tacoma290
Active Member
Got the pumps put back together last night. I filled the filter bowl and the pump bowl about 1/3 of the way up with fuel so the pumps already have fuel at startup. Will get them installed this weekend, and will fight to get the fuel system re-primed. Let me know if there are any tricks.
Pump is reading for install:
Here is a close-up of the top cap from A & J. The inside of the cap is the same matte finish, and is not painted. Much better from a flaking perspective. Ignore the one bolt that replaced the one that was snapped off; Apparently the original bolts are very pricy from Mercruiser.
And I picked up some stainless bolts from Tacoma Screw to take the place of the blue plastic plugs. The bolt threads are 1/2"-13. I used the o-ring gasket from a new plastic plug with these bolts, and used anti-seize on the threads.
Again, if there are any tips for getting the system primed, that would be welcome. The fuel rails are dry since I had them cleaned.
Pump is reading for install:
Here is a close-up of the top cap from A & J. The inside of the cap is the same matte finish, and is not painted. Much better from a flaking perspective. Ignore the one bolt that replaced the one that was snapped off; Apparently the original bolts are very pricy from Mercruiser.
And I picked up some stainless bolts from Tacoma Screw to take the place of the blue plastic plugs. The bolt threads are 1/2"-13. I used the o-ring gasket from a new plastic plug with these bolts, and used anti-seize on the threads.
Again, if there are any tips for getting the system primed, that would be welcome. The fuel rails are dry since I had them cleaned.
douglee25
Well-Known Member
Should just be able to cycle the key and it should prime. Anytime I've worked on cool fuel modules that's all I've ever done.
Tacoma290
Active Member
Ok, new problem. The fuel rail leaks at the cross fitting. See photo. How do I deal with that?
douglee25
Well-Known Member
Should just be an oring in there I believe.
Tacoma290
Active Member
Took it all apart and re-aligned. No leaks.
douglee25
Well-Known Member
Does it all work?
Tacoma290
Active Member
The starboard side system in the photo now works beautifully.
The port side had slightly lower pressures from the gauge; the engine ran fine but the gauge was telling me I needed to do more. I took the pump assembly out and apart (again), to find out that the rubber inlet seal to the low pressure pump has a tear in it, that allows fuel to bypass. The assembly I purchased from S&J did not come with a new seal. So this morning I am working on sourcing a replacement seal.
The port side had slightly lower pressures from the gauge; the engine ran fine but the gauge was telling me I needed to do more. I took the pump assembly out and apart (again), to find out that the rubber inlet seal to the low pressure pump has a tear in it, that allows fuel to bypass. The assembly I purchased from S&J did not come with a new seal. So this morning I am working on sourcing a replacement seal.
douglee25
Well-Known Member
Nice work.
sejensen737
Active Member
These things are a PITA. Been there , done that.
Just a tip for when you try and fire her up again...I had a very hard time priming my new CFM. Tried all sorts of stuff but what finally worked was bleeding the fuel rail via the schrader valve when you turn the fuel pump on. Might have to cycle the pump a few times but you will know when all the air is out when she sprays a steady stream of fuel. Keep rags handy...
Just a tip for when you try and fire her up again...I had a very hard time priming my new CFM. Tried all sorts of stuff but what finally worked was bleeding the fuel rail via the schrader valve when you turn the fuel pump on. Might have to cycle the pump a few times but you will know when all the air is out when she sprays a steady stream of fuel. Keep rags handy...
techmitch
Well-Known Member
- May 1, 2008
- 8,334
- Boat Info
- 1999 270 DA
- Engines
- Twin 4.3s W/Alpa I Gen II's
Tacoma290
Active Member
Things have not gone as I had hoped.
Got the replacement seal, and put the pump together, reinstalled, and dropped the fuel rails back in. I keyed it on and pressure came up, then dropped. I keyed again and it happened again. This was new, no leaks were observed. What I should have done is keyed the system with the rails above the engine not in the engine. I did not do this, and then I did hit the starter.
What I would have observed was that one of the injectors had opened and would not close; the cylinder had a ton of fuel. The starter bounced off the flywheel, and the engine was hyro-locked (petro-locked?).
Lessons:
Got the replacement seal, and put the pump together, reinstalled, and dropped the fuel rails back in. I keyed it on and pressure came up, then dropped. I keyed again and it happened again. This was new, no leaks were observed. What I should have done is keyed the system with the rails above the engine not in the engine. I did not do this, and then I did hit the starter.
What I would have observed was that one of the injectors had opened and would not close; the cylinder had a ton of fuel. The starter bounced off the flywheel, and the engine was hyro-locked (petro-locked?).
Lessons:
- In addition to replacing/upgrading with the cool fuel pump, cleaning the injectors, and cleaning the rails, blow out the fuel pipe from the pump to the rails. Later on, I did find a small bit of debris that made its way to this injector. We believe the only source left was the pipe.
- After installing the pump and before dropping the rails in, key the engine on with the rails above the cylinders so the injectors can be visually verified to close. A little fuel on top of the engine where it can be observed is risk, but a tolerable risk.
- If the fuel pressure drops, know the cause before starting the engine.
Tacoma290
Active Member
Yes, I was able drain the gas, and was able to crank over without plugs, then put them back and got the engine started. But there is a noticeable metal on metal sound (more than valve train); the sound follows the RPM.
Compression test was okay, and leak down test was okay at that #8 cylinder and its neighbor. Pulled the intake and the head. The head looks fine visually, but I suppose I could have it tested.
The #8 cylinder has a noticeable lower Top Dead Center and noticeable lower Bottom Dead Center than the others on that side.
I can roll the crank over by hand easily except at one spot: When #8 is at BDC, it gets tough and I need to use a breaker bar to keep turning. Once I get by that, it is easier until I return again to #8 BDC.
I am no expert, but it feels like a bent connecting rod, and it is contacting the block at the bottom.
Compression test was okay, and leak down test was okay at that #8 cylinder and its neighbor. Pulled the intake and the head. The head looks fine visually, but I suppose I could have it tested.
The #8 cylinder has a noticeable lower Top Dead Center and noticeable lower Bottom Dead Center than the others on that side.
I can roll the crank over by hand easily except at one spot: When #8 is at BDC, it gets tough and I need to use a breaker bar to keep turning. Once I get by that, it is easier until I return again to #8 BDC.
I am no expert, but it feels like a bent connecting rod, and it is contacting the block at the bottom.
scoflaw
Well-Known Member
- Aug 10, 2011
- 6,395
- Boat Info
- 1999 Powerquest legend 260 sx 502 mag
2005 Baja 242 islander 496
- Engines
- 502 mpi Bravo 1
496 mag B1
bummer
Damn, sorry. Pulling the engine out next or further tear down/testing? I’d imagine an oil sample would confirm metal traces but wouldn’t confirm from where, necessarily.