Fuel Pressure Problem

[Fun Times]

Re: Fuel Pressure Problem

Well I replaced the fuel pressure regulator by the fuel pump and the fuel pressure went up to 34 psi (engine running). I removed the vac line to the fuel pressure regulator on the fuel rail and the pressure jumped up to 40 psi. so all these numbers are better but i still have the knock in the engine. so the low pressure was not the cause.

Good job

Take a look at number 7 in this link beow, If you have a exhaust system like this set up then there is a chance number 7 has lost the rubber around the metal flap and it's pretty common to hear a knocking sound that will make you think the engine is broke some place in a bad way, You will need to pull it a part to see if they are good or not. Good luck with it.

http://www.mercruiserparts.com/Show...g&inbr=2342&bnmetalbr=29&bdesc=EXHAUST+SYSTEM

 

[winstonwilliams]

Re: Fuel Pressure Problem

I think tomorrow I am going to get a stethoscope and listen to find out exactly where the knocking is located... If it is in the exhaust like you suggested I should be able to hear the noise coming right from that location. Correct?

Thanks again for all your help... Hopefully between all of us we will be able to figure this out!!

Winston

 

[winstonwilliams]

Re: Fuel Pressure Problem

I could not find a stethoscope around town, so went ahead and ordered one off of ebay. I tried to use a rubber hose to funnel the sound to my ear, but I could not find exactly where the sound was coming from. I did notice that the knocking was louder inside of the valve covers. I would think that if it was a lifter or valve problem the noise would be louder under one valve cover than the other. But to me they sounded the same... What do you guys think? the knocking is very loud some times and almost goes away other times

Thanks

Winston

 

[Glastron_V210]

Re: Fuel Pressure Problem

I'm glad your fuel pressure is back, 1 problem down, 1 to go....be happy you are making progress!

You told us that the knock increases with rpm...is that still the case?

If it was me I'd pull the valve covers because they are easy to get to, and look for broken rockers and misadjusted (loose) rockers. Just remember to clean and vaccuum the engine so as not to introduce dirt into the engine.

You may want to run it for a bit with the coves off....messy, but you'll know right away if it is valve train related.

If it's not the rockers, it could be a broken pushrod. If it's not that it starts to look more like a wrist pin/crank bearing etc, so hope it's valve train! It's hard to believe that a bearing or wrist poin would go away, but I don't really have much experience with failing internal components; I've been lucky so far.



Chay

 

[winstonwilliams]

Re: Fuel Pressure Problem

yes the knock increase with the rpms... I pulled one of the valve covers and everything looks ok, but I did not run the engine while it off.... guess I need to go ahead and pull the other one.

Thanks again for all the help

Winston

 

[winstonwilliams]

Re: Fuel Pressure Problem

Bad news :-(

I removed the oil filter and cut it open.. There are metal shavings in the filter! This means the rod bearings are shot right?

Winston

 

[Fun Times]

Re: Fuel Pressure Problem

Bad news :-(

I removed the oil filter and cut it open.. There are metal shavings in the filter! This means the rod bearings are shot right?

Winston

Could be, Sorry to hear about that, At least you have your fuel pressure back up so you won't half to fight that any more after what ever your next step need's to be to get this engine running right again. Good luck to you with it.

What color was the metal shavings you found?

 

[winstonwilliams]

Re: Fuel Pressure Problem

Silver

 

[Fun Times]

Re: Fuel Pressure Problem

Silver

I'm not all that sure myself Because It's been a long time since I have tore down a engine myself, But the rod bearings could be silver. Anybody eles here on iboats have any other ideas on this silver in the oil filter??? Thank's