99 SN GT40 Fuel Supply

There are a number of us GT-40 folks lurking on the forums (a number of them have quite a bit of experience with troubleshooting the ECC, etc.). So I'd say you are in good hands (keeping in mind how much you are paying for this advice....)   

Ignore the last paragraph. I was going to delete it after I changed the paragraph above it. :-)

No fuse on my battery line. I have seen that has caused intermittent problems for some, but I don't have one. Good thought though.    

Here is a link to a video I made of the boat running in the driveway. I removed the regulator hose, and this time, the pressure had dropped to zero, but you can hear the rpms pick up a little. When I did this when the pressure was at 35 lbs, it jumped to 40.

You can hear the pumps sucking air as the pressure drops.

The boat ran great and then viola, this is what it did on the lake on the last ski ride for last season.

http://www.youtube.com/watch?v=0hihpHcuNvY

I am just south of Toledo. The lake is alongside the Ohio turnpike. Look at Google Ski Sites, it is The Slalom Club (I know, real creative name).

My dad gave me the meter. I guess I have tested batteries with it, and that is about the extent of me using it.....

Al you can make both pumps run by shorting the end terminal of the STO connector to ground (ECC Test connector above relays). You should have 39 +- 3psi with key on engine off and 31 +- 3psi at idle. With the vacuum hose removed at regulator and engine running you should see max pressure mine reads almost 44psi.

I would also check the volume of fuel the low pressure pump puts out.

Al,
Set the meter to any Ohm range. What happens when you touch the two probes?

If one of the probes was grounded on the block and then you touched the ground wire feeding the pump with the other probe, what should happen?

What have you been using the meter for?

8122, I am somewhat electrically challenged. I have a meter, but really don't know how to use it very well.

How would I check for ground?

I have turned a few wrenches in my time, but not dealt with a lot of electrical stuff. My dad was the electrician, plumber, welder, etc....

Thanks

At the end of last seaon, after a couple passes through the course, my engine died when I applied power to take off. It would idle fine, but would die with a gasping sound every time I gave it gas. Couldn't even power up on the trailer.

Since that time, I booght a pressure gauge and have observed some very strange readings. It will run about 35 psi, then fluctuate widly and go to zero. I removed the Regulator hose and saw it momentarily jump to 40 psi, then go through all the ups and downs as before.

The pumps do not always prime, so I have been inclined to think it is a power issue to the pumps. I replaced the relays, as I had sufferred through that diagnosis two years ago, and have a two year old low pressure pump, ant-syphon valve, and kill switch to thank for that one.

The plugs and distributor cap and rotor are new.

The hi pressure pump and filter are new along with the FCC housing, as I developed a gas leak through the fitting on top of the old FCC when I was checking the hi pressure pump and filter. (that was a $450 ouch). I also replaced the 15 amp circuit breaker, as that seemed like it was frozen.

I completely drained the fuel tank when I repacked the rudder this spring, so I am pretty sure nothing in the tank is plugging the line. I have no in line filter, only the one in the fcc.

I have followed the electrical lines back to the fuses, and all connections seem clean and tight.

I want to jump the low pressure pump direct to the battery, and am making up some alligator clips to go direct to the low pressure pump to see if this makes a difference.

Does anyone know what terminal on the low pressure pump is positive vs negative? I am thinking I need to run off the battery to the positive post and vice versa for negative. I am thinking this might confirm that the low pressure pump is good.

The other question is what else can I look at that would cutoff power to the pumps? I replaced the relay this year, as I have two spare ones. That made the pumps prime, and I thought I might have fixed it like last time, but, that was just a coincidence of the problem.

What is odd is that the engine will not take gas, consistently. If the pumps are randomly running, you would think that I could at least get rpms randomly.

This one is a real head scratcher. The guys from Ski Dim and White Lake have been great, but we are just shooting at the sky right now, and the season is right around the corner. My dealer is no longer in business, and the next guy is 2 hours away, and I don't know him well.

Any ideas?