low_psi

Fuel pressure should be stock. I think I remember putting a gauge on it and it was in the neighborhood of 44 psi.... Do you remember actually seeing raw fuel in the water with Mick's? Last year, the boat ran great with the whipple flash, but had the oily soot, which turned out to be a bad intake gasket. Now I still have soot but not oily and greesy like before. My main issue is it stumbles and sputters under load at about 1/2-3/4 throttle. And also a flat spot in the throttle at about 1/8, where rpm actually goes down... These two issues began this season...... It has new plugs, all cylinders checked out good with a compression test and leak down and new MAP sensor...

I will take a fuel gauge with me next time I go out and look to see what pressure is at idle and all the way through. If a leaky injector, would I see a drop in psi while the boat sits with motor off (over an afternoon)?

I saw mick out there Friday, boat looked and sound good....

Pwraddr

Pop the rail out, turn the key on and then off. Let the rail sit on a paper towel and see if any fuel leaks out.

Leaving the gauge sit on the rail is typically not a good indicator as there are other variables. Gauge, hook up, etc.

brian41

iTrader: (1)

Yes Mick's left a film on the water behind the boat at idle.

First step is to put it on a scanner. Look at the values and check codes. Then do a cylinder balance check, you may have cracked a plug or 2 installing them.This will also help find a "bad" injector(s).

articfriends

iTrader: (1)

A real easy check you could do in just minutes on the water IF you have a adjustable fuel regulator without spending anymore money is: install your fuel press gauge if you don't have a permenent one, if pressure is at 40 turn it to 36 and see if problem is same, worse or better. If its worse turn it up 4 psi MORE than you started with initailly, if its better or worse you have found your problem, the fuel table tune/bpw is wrong. I just went thru this on my own boat and another, My fuel press is usually at 40 psi when not in boost, when I fired my boat up the for first time this year it was reading 32, so I adjusted my regulator until gauge read 40 , my boat was then sputtering and terrible acting, I started thinking I had a injector failing or something so in the course of trouble shooting I put a high quality mechanical gauge on it and found the dash gauge was off by 8 psi, when I set it back where it was (at 32 psi) it cleaned right up so I am replacing my electric gauge. The second one I just seen was fellow osoer "onesickpantera" is working on his efi tune, he had a stumble around 1000-1200 rpm's, I am helping him with his tune thru the mail (sending mefi ecu's back and forth), he turned his fuel press up 4-6 psi and the stumble was gone, he turned it down and it was worse so I am adding a little fuel to his tables around 1000 rpms as we know it needs more fuel. Don't keep driving it though IF turning it down cleans it up or drive it at wot while testing as it may be lean somewhere else and melt down, at that point send your ecu back to your tuner to be leaned out or richened up!

low_psi

Brian,

Do you have the software/tools to read my codes? If so do you have the time? If you have the time, when? How much would you charge? I can bring it to you on the trailer and/or launch it down by you so it is in water..... I have been running all season this way, so if you cant look at it right away, that's fine. The sputtering is my main concern, and that started at the begining of this season. I changed spark plugs once I noticed the sputtering. A new set of plugs made no difference.. One thing I have not looked into is plug wires........ But probably start with codes first.

Also a small bit of history.... Last time out last season, I hit something in Erie and ripped the Starbord Trim tab completly off of the boat. There was some minor glass damage that was repaired last year. When it tore off, it was on the way to PIB. I didn't realize it had happend until we left PIB at the end of the day. Since I seldom use the tabs, I didn't know it was missing until we went to plane off leaving PIB. While it sat at PIB it took on some water, enough so that I had to have the Starter replaced because it had been partially submerged. (my bilge pump is on a manual on/off switch). Is there anything electrical/electronic located toward the bottom of the motor that may have seen some moisture damage? Until tonight, I had not even though that that incident may be related, but the boat was winterized after the repair. Then the first time out this season the sputtering began...... Hmmmmm.

brian41

iTrader: (1)

Yes I do have the software needed to test.Shop rate is $80.00 an hour and diagnosis should take less than 1 hour. We handle most repairs within 1 day of arrival.Call me at 734-586-0448 and we can set up a time to take care of your problem.

low_psi

Haven't had time to wrench on the boat yet, but an observation.... When we are out with the boat off and hanging out behind the boat, Every once and a while we can smell raw fuel. Not constant but randomly every 10 minutes or so... It isn't coming from the engine compartment at all, it seems to be coming from the exhaust. However, not every time out. Today we didn't smell it at all but yesterday we could. Again, just guessing at it at this point, but this maybe a bad injector bleeding off. Depending on which valves are open would determine if we smell it behind the boat? I have also notice it takes a few more cranks to get it started after the boat sits overnight.

I am going to try and pull the fuel rails this week and see if I can locate the leaky injector....

low_psi

I know this isn't going to tell me for sure, but I lost all fuel pressure within hours of shutting the boat off. It dropped 20lbs in the first hour... Think it is time to pull the injectors to see which one(s) is leaking.

boatnt

iTrader: (1)

normal..
.thats why every time you cycle the ignition key to the on position a relay turns on the fuel pump to prime the fuel system..