Thought I had it fixed....But.....aargh!

[jimc_LA]

OK. Brief history. Had fuel deliver issues because of boat setting up for over a year. Pumped out 25-30 gal. of old gas, installed remote fuel/water separator, replaced high pressure fuel pump and strainer(old one siezed up), cleaned everything out while I had the VST broken open (including float/needle valve and seat), new o-ring gasket on tank, replaced fuel lines from hp punp to fuel rail and from fuel rail back to tank (old ones had hairline cracks), took fuel pressure regulator loose and inspected (looked clean), added Sta-Bil to fuel tank this time, low pressure pump seems to be working fine, ball and fuel lines to tank appear to be free.....$700+ later, here's what I have:

Pumped up ball and got hard, no visible leaks in anything I touched (huray!), turned key on and heard hp pump running, fired her up and she cranked up pretty quickly, idled great. Shut her down and used a psi gauge on the end of a hose and removed pressure release valve insert from test port and connected hose with psi valve. Turned key back on and gauge only reading 12psi+/-, Merc manual says should be 32-36psi. Removed gauge and replaced valve insert. Turned key and she started instantly. Used high idle lever and ran her up top about 2,000 rpm and seemed fine.

I'm woried that I still have a problem. Won't be sure until I get her on the water, but I think the low psi at the high pressure pump discharge is going to cause delivery problems at higher rpm's. Merc manual says low pressure here is likely to be the fuel pressure regulator. Called around and, of course, no one has it in stock locally. Was desperately trying to use boat this weekend because step-son coming to town.

Two questions:

1) Could the fact that I used a standard "air" type psi gauge be the reason the pressure read low?

2) If it is the pressure regulator, does anyone know of something I could try to "free it up"? It appears to be a vacuum controlled diaphram.

Any help here would be greatly appreciated. I don't think that I can mail order a part and have it by tommorow or Saturday.

It's always something.....

 

[j_martin]

Re: Thought I had it fixed....But.....aargh!

1. I don't think the gauge makes a difference, unless you have pulsing or vibration making it hard to read, in which case a fluid filled gauge is steadier.

2. I don't know the details of the regulator, but I do know that if you are short of fuel at high speeds, you can burn down the whole engine in a heartbeat. I'd be sure I have good numbers before I try to run it.

3. (going forward) When you do get it on the water, watch carefully for any indication it isn't running right. If it seems right, try a short high speed run, shutting down at WOT if possible. (my boat would sink stern first if I did that), and pull and read the plugs. If possible look into the bores also. Any sign of lean in a single cylinder could be an injector problem, which is very likely given the skunk gas scenerio you've been presenting.

hope it helps
John

 

[jimc_LA]

Re: Thought I had it fixed....But.....aargh!

John,

Thanks for the input.

After running in driveway last evening, I pulled all of the plugs and all were wet. She fires instantly after first being cranked and idles very smoothly.

I'm going to order a new regulator, but when I get home today, I'm going to try and do some work on the existing one. It seems like such a small, simple device and it looked very clean when I inspected it.

Always the case, though. I've had the parts I replaced for a copule of weeks, weather and other issues have prevented me from installing until yesterday and now, I find I may need another part and won't have it in time.

Regardless, I think that I have to take it on the water this weekend just to see what happens. Having inspected and cleaned everything out, I thought I had it licked. I think that my biggest problem was isolated to the fuel in the VST. It was pretty bad in there and must have also had some moisture as there was some surface rust on some of the parts. Fuel I pumped out of the tank looked and smelled pretty good. Ran it through the daily driver a bit at a time with no problems.

I hope I get this all worked out soon. I'd hate for this to end up being one of those long drawn out deals which take lots of time and much more $$ to resolve.

Anyway, thanks again for the input.

Jim C.
Covington, Louisiana

 

[j_martin]

Re: Thought I had it fixed....But.....aargh!

When you finally can it, it may plug an injector. Some of them had screens in them, and the recommendation is to discard them in a normal engine.

Might just be the final filter you need to get it going. Plug em up, and throw them away. (the screens)

Just be careful you don't burn down a good cylinder doing it.

Good luck
John

 

[jimc_LA]

Re: Thought I had it fixed....But.....aargh!

Ordered a new pressure regulator a while ago. Of course, it won't be here for about a week. Still going to try to mess with the existing one and see if I can get the pressure up.

If by the final filter you mean the screen type at the botom of the hp fuel pump, it's brand new, came with the pump kit.

Do you know if you can run injector cleaner through these motors, like you do with your vehicle? Thought I'd put a bottle of gumout in the tank and run through it.

I'll take a look at the two fuel/water filter/separators as well. See if any trash was left in the tank. Seemed pretty free when I pumped the ball to fill vapor seperator tank. I could hear it rushing in.

Jim C.

 

[j_martin]

Re: Thought I had it fixed....But.....aargh!

I mean the screens that are part of the injectors.

Check out this thread

http://forums.screamandfly.com/forums/showthread.php?t=82890


hope it helps
John

 

[jimc_LA]

Re: Thought I had it fixed....But.....aargh!

John,

Sounds like most folks on that forum board think that it's better to use good, brand name gas than to waste the money putting injector cleaner in. That's fine, I usually use Shell premium, so that's good, the added injector cleaner might just help spruce things up in there a bit more.

I've read a lot of posts here about folks adding a bit of SeaFoam to their fuel, which apparently acts like a detergent additive. Is this practice as common as it seems on this board?

Regarding the injectors and filter screens, I've never gone down that road before. Are they hard to access/remove on a '00 Merc 200 EFI? More uncharted territory, but I guess as long as it stays short of tearing down the engine to replace bearings, rods and the like I',m OK....

Thanks for all of your help.

 

[j_martin]

Re: Thought I had it fixed....But.....aargh!

I don't know, but the boys over on scream and fly sure do. They are very helpful, also. Like most boards, you have to sort out the BS, but they often help you with that also, and it can get quite funny.

Here's a helpful hint, make the title informative about the motor type and trouble, instead of an emotional personal problem thing. You'll get a better and more informative response.

hope it helps
John