500 EFI losing rpm's
Charter Member
05-01-2006, 08:33 PM
#13
Re: 500 EFI losing rpm's
I pulled a couple plugs and the electrodes have been shortened almost half of a new plug.
So it looks like it's running lean. Like I said ealier it has a fuel pump for the 502's do they use the same size fuel pumps as the 500EFI. Also with talking to Dock Holiday it does not have the auxilliary mechanical fuel pumps on the sea water pumps.
What is the easiest way to add fuel pressure? Can you do this with an auxilliary electric fuel pump? If so how is the best way to plumb it?
So it looks like it's running lean. Like I said ealier it has a fuel pump for the 502's do they use the same size fuel pumps as the 500EFI. Also with talking to Dock Holiday it does not have the auxilliary mechanical fuel pumps on the sea water pumps.
What is the easiest way to add fuel pressure? Can you do this with an auxilliary electric fuel pump? If so how is the best way to plumb it?
05-01-2006, 09:12 PM
#14
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Re: 500 EFI losing rpm's
The 500 Efi Did Not Always Have A Sea Pump With Fuel
Aux...the Stock Efi Pump Is Plenty If It Is Working Properly...a Fuel Pressure Gauge Will Save You Alot Of Headaches.
Aux...the Stock Efi Pump Is Plenty If It Is Working Properly...a Fuel Pressure Gauge Will Save You Alot Of Headaches.
05-02-2006, 09:56 PM
#16
VIP Member
Re: 500 EFI losing rpm's
Originally Posted by Steel Outlawed
I pulled a couple plugs and the electrodes have been shortened almost half of a new plug.
So it looks like it's running lean. Like I said ealier it has a fuel pump for the 502's do they use the same size fuel pumps as the 500EFI. Also with talking to Dock Holiday it does not have the auxilliary mechanical fuel pumps on the sea water pumps.
What is the easiest way to add fuel pressure? Can you do this with an auxilliary electric fuel pump? If so how is the best way to plumb it?
So it looks like it's running lean. Like I said ealier it has a fuel pump for the 502's do they use the same size fuel pumps as the 500EFI. Also with talking to Dock Holiday it does not have the auxilliary mechanical fuel pumps on the sea water pumps.
What is the easiest way to add fuel pressure? Can you do this with an auxilliary electric fuel pump? If so how is the best way to plumb it?
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
05-05-2006, 06:27 AM
#17
Re: 500 EFI losing rpm's
Ok here is the latest. I swapped the fuel lines coming from the tank, just to rule out a pick-up problem in the tank. Changed the plugs, changed the electronic module on the distributor all before taking it out last night.
I warmed up the engines, then went for a test run. First run I got up to 5100+ before backing off. The second run it would not go above 4700 and the third run it would not go above 4700. Also on the 2nd and 3rd run it did not start losing rpms like it had before. I have not checked the fuel pressure yet, I will try that this weekend.
I warmed up the engines, then went for a test run. First run I got up to 5100+ before backing off. The second run it would not go above 4700 and the third run it would not go above 4700. Also on the 2nd and 3rd run it did not start losing rpms like it had before. I have not checked the fuel pressure yet, I will try that this weekend.
05-07-2006, 12:41 PM
#19
Re: 500 EFI losing rpm's
We tested the fuel pressure yesterday. It was 38-39 psi on both motors at idle and mid throttle. Did not run it up because of the problems. We took the vacuum line off the regulator and got 42 psi.
What fuel pressure are the 500 efi's supposed to be?
What fuel pressure are the 500 efi's supposed to be?
05-09-2006, 03:25 PM
#20
Re: 500 EFI losing rpm's
Let's back up a little and mention a couple things.
I took the boat to get both engines tuned up and looked over. Here is what they did to both engines before we discovered we had a problem with the port engine.
They changed plugs, wires, cap, rotor, thermostat, impeller kits, and removed the braided fuel lines and ran stock 1/2" hoses.
After they completed the tune up is when they found out we had a problem with the port engine. So they pulled the port engine and did a complete rebuild. Since I got it back I have had problems with both engines neither engine will turn over 4800. When we had the computer hooked up, we did see that the port engine was retarding the timing correctly. But the starboard engine was not. So I'm going back to what they changed to see if one of those could be the problem. The plug wires seem to pop off the distributor very easy. I'm wondering if the wires could be causing this problem?
Like I said in the previous post the fuel pressure seems to be good. Through out the rpm range.
I took the boat to get both engines tuned up and looked over. Here is what they did to both engines before we discovered we had a problem with the port engine.
They changed plugs, wires, cap, rotor, thermostat, impeller kits, and removed the braided fuel lines and ran stock 1/2" hoses.
After they completed the tune up is when they found out we had a problem with the port engine. So they pulled the port engine and did a complete rebuild. Since I got it back I have had problems with both engines neither engine will turn over 4800. When we had the computer hooked up, we did see that the port engine was retarding the timing correctly. But the starboard engine was not. So I'm going back to what they changed to see if one of those could be the problem. The plug wires seem to pop off the distributor very easy. I'm wondering if the wires could be causing this problem?
Like I said in the previous post the fuel pressure seems to be good. Through out the rpm range.
