496 Fuel Pressure Regulator
06-19-2012, 06:08 PM
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496 Fuel Pressure Regulator
Need help finding the Pressure Regulator on my 496, I have little bit of a soot issue and when i called Mercury to ask if my 2003 496 was part of a recall i had read about because of soot on the transom (it was not part of any service recall) they suggested i check the vaccuum line attached to the presssure regulator for fuel saying if i dripped fuel the diaphragm was ruptured in the regulator and this would let in to much fuel and could cause the problem. Sorry i really didnt want to start another soot thread and based on what i have seen on here mine is not nearly as bad as soom others.
06-19-2012, 08:07 PM
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Dont fool with the regulator, just reprogram the ECU. If you were too look at how simple the 496 regulator is and how simple it can break, it just isnt worth it.
06-19-2012, 10:00 PM
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Not following you Keith? what do you mean by how simple it is a breaking it? I heard about the ECU recall and reflash but the one person i knowo who had that done actually lost a few mph after the reflash.
06-20-2012, 12:05 PM
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Again, I don't know who trains or teaches these Mercury service desk techs sometimes? but if a fuel pressure regulator diaphram like the Merc fixed fuel pressure regulator, the only thing that is going to happen is the fuel pressure will not adjust down under higher manifold vacuums 1-2 psi at idle and the preset fixed fuel pressure will stay at 43psi and even though that can cause the engine to idle just a little bit fatter at idle, unless you do a ton of idling it should not make a big difference as for the transom soot.
I'll bet $10 right now that there is no ruptured diaphram in your regulator, just makes the techies at Mercury fell more important to throw that one out there!
First, real easy to check the regulator without removing it and replacing it. Take the vacuum line off at the other end of the this line and either use a suction pump tool or just you mouth and suck on the tube and see if it holds suction, if it does the diapharam in the regulator is not ruptured. If it won't hold vacuum then the regulator has a ruptured diaphram -(very rare) and should be replaced.
Second, whats the year and model of your engine and what's the serial type of the ECM from the ECM label and the date on the ECM?
couple of do's and don't here:
See if you can get Merc to do their adjustment reprogam on the ECM that they did on a lot of 2001-2003 year model 496's that were running way to fat with Mercury's original programming. Mercury can tell you from the ECM serial number whether your ECM was one involved in that reprogram program. If you're the second owner or the engine is to far out of warranty they will most likely bail on reprogramming it to their newer cals.
Do not run premium 91-93 octane fuel in stock Merc 496's, it does not burn quickly or completely and it will add to transom soot and its not good for the rings!
Try changing fuel brand types, some fuel brands and blends are worse for soot and fuel burn charactersistics.
Is the soot very oily? if it is you may have oil burning issues form either a possible intake gasket leak problem on 2000-2004 Merc (GM) 496's.
Don't change the thermostat in a stock Merc 496 to a too cold type as the engine may in some cold water enviroments not come up to a 160 degree operating temperature and the ECM will keep the fuel trims out of adjustment for correct air/fuels, it will run fat.
Remember a lot of todays pump gas has addtivies and compounds and blends which seem to cause a lot of blac exhaust soot. we confirm this on our engine dynos, when we set air fuels fairly on the lean side, see black exhaust soot in the exhaust after running on the dyno, we subsitute test fuel with no addtives and the exhaust turns a nice medium gray with no black soot. Pretty good proof a lot of todays soot is from the fuel blends not the ECM tune.
No one likes the soot, but unless you've got pull at the EPA or refiners, it ain't gonna get better or change!
Best Regards,
Ray @ Raylar
I'll bet $10 right now that there is no ruptured diaphram in your regulator, just makes the techies at Mercury fell more important to throw that one out there!
First, real easy to check the regulator without removing it and replacing it. Take the vacuum line off at the other end of the this line and either use a suction pump tool or just you mouth and suck on the tube and see if it holds suction, if it does the diapharam in the regulator is not ruptured. If it won't hold vacuum then the regulator has a ruptured diaphram -(very rare) and should be replaced.
Second, whats the year and model of your engine and what's the serial type of the ECM from the ECM label and the date on the ECM?
couple of do's and don't here:
See if you can get Merc to do their adjustment reprogam on the ECM that they did on a lot of 2001-2003 year model 496's that were running way to fat with Mercury's original programming. Mercury can tell you from the ECM serial number whether your ECM was one involved in that reprogram program. If you're the second owner or the engine is to far out of warranty they will most likely bail on reprogramming it to their newer cals.
Do not run premium 91-93 octane fuel in stock Merc 496's, it does not burn quickly or completely and it will add to transom soot and its not good for the rings!
Try changing fuel brand types, some fuel brands and blends are worse for soot and fuel burn charactersistics.
Is the soot very oily? if it is you may have oil burning issues form either a possible intake gasket leak problem on 2000-2004 Merc (GM) 496's.
Don't change the thermostat in a stock Merc 496 to a too cold type as the engine may in some cold water enviroments not come up to a 160 degree operating temperature and the ECM will keep the fuel trims out of adjustment for correct air/fuels, it will run fat.
Remember a lot of todays pump gas has addtivies and compounds and blends which seem to cause a lot of blac exhaust soot. we confirm this on our engine dynos, when we set air fuels fairly on the lean side, see black exhaust soot in the exhaust after running on the dyno, we subsitute test fuel with no addtives and the exhaust turns a nice medium gray with no black soot. Pretty good proof a lot of todays soot is from the fuel blends not the ECM tune.
No one likes the soot, but unless you've got pull at the EPA or refiners, it ain't gonna get better or change!
Best Regards,
Ray @ Raylar
Last edited by Raylar; 06-20-2012 at 12:12 PM.
06-20-2012, 07:29 PM
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Again, I don't know who trains or teaches these Mercury service desk techs sometimes? but if a fuel pressure regulator diaphram like the Merc fixed fuel pressure regulator, the only thing that is going to happen is the fuel pressure will not adjust down under higher manifold vacuums 1-2 psi at idle and the preset fixed fuel pressure will stay at 43psi and even though that can cause the engine to idle just a little bit fatter at idle, unless you do a ton of idling it should not make a big difference as for the transom soot.
I'll bet $10 right now that there is no ruptured diaphram in your regulator, just makes the techies at Mercury fell more important to throw that one out there!
First, real easy to check the regulator without removing it and replacing it. Take the vacuum line off at the other end of the this line and either use a suction pump tool or just you mouth and suck on the tube and see if it holds suction, if it does the diapharam in the regulator is not ruptured. If it won't hold vacuum then the regulator has a ruptured diaphram -(very rare) and should be replaced.
Second, whats the year and model of your engine and what's the serial type of the ECM from the ECM label and the date on the ECM?
couple of do's and don't here:
See if you can get Merc to do their adjustment reprogam on the ECM that they did on a lot of 2001-2003 year model 496's that were running way to fat with Mercury's original programming. Mercury can tell you from the ECM serial number whether your ECM was one involved in that reprogram program. If you're the second owner or the engine is to far out of warranty they will most likely bail on reprogramming it to their newer cals.
Do not run premium 91-93 octane fuel in stock Merc 496's, it does not burn quickly or completely and it will add to transom soot and its not good for the rings!
Try changing fuel brand types, some fuel brands and blends are worse for soot and fuel burn charactersistics.
Is the soot very oily? if it is you may have oil burning issues form either a possible intake gasket leak problem on 2000-2004 Merc (GM) 496's.
Don't change the thermostat in a stock Merc 496 to a too cold type as the engine may in some cold water enviroments not come up to a 160 degree operating temperature and the ECM will keep the fuel trims out of adjustment for correct air/fuels, it will run fat.
Remember a lot of todays pump gas has addtivies and compounds and blends which seem to cause a lot of blac exhaust soot. we confirm this on our engine dynos, when we set air fuels fairly on the lean side, see black exhaust soot in the exhaust after running on the dyno, we subsitute test fuel with no addtives and the exhaust turns a nice medium gray with no black soot. Pretty good proof a lot of todays soot is from the fuel blends not the ECM tune.
No one likes the soot, but unless you've got pull at the EPA or refiners, it ain't gonna get better or change!
Best Regards,
Ray @ Raylar
I'll bet $10 right now that there is no ruptured diaphram in your regulator, just makes the techies at Mercury fell more important to throw that one out there!
First, real easy to check the regulator without removing it and replacing it. Take the vacuum line off at the other end of the this line and either use a suction pump tool or just you mouth and suck on the tube and see if it holds suction, if it does the diapharam in the regulator is not ruptured. If it won't hold vacuum then the regulator has a ruptured diaphram -(very rare) and should be replaced.
Second, whats the year and model of your engine and what's the serial type of the ECM from the ECM label and the date on the ECM?
couple of do's and don't here:
See if you can get Merc to do their adjustment reprogam on the ECM that they did on a lot of 2001-2003 year model 496's that were running way to fat with Mercury's original programming. Mercury can tell you from the ECM serial number whether your ECM was one involved in that reprogram program. If you're the second owner or the engine is to far out of warranty they will most likely bail on reprogramming it to their newer cals.
Do not run premium 91-93 octane fuel in stock Merc 496's, it does not burn quickly or completely and it will add to transom soot and its not good for the rings!
Try changing fuel brand types, some fuel brands and blends are worse for soot and fuel burn charactersistics.
Is the soot very oily? if it is you may have oil burning issues form either a possible intake gasket leak problem on 2000-2004 Merc (GM) 496's.
Don't change the thermostat in a stock Merc 496 to a too cold type as the engine may in some cold water enviroments not come up to a 160 degree operating temperature and the ECM will keep the fuel trims out of adjustment for correct air/fuels, it will run fat.
Remember a lot of todays pump gas has addtivies and compounds and blends which seem to cause a lot of blac exhaust soot. we confirm this on our engine dynos, when we set air fuels fairly on the lean side, see black exhaust soot in the exhaust after running on the dyno, we subsitute test fuel with no addtives and the exhaust turns a nice medium gray with no black soot. Pretty good proof a lot of todays soot is from the fuel blends not the ECM tune.
No one likes the soot, but unless you've got pull at the EPA or refiners, it ain't gonna get better or change!
Best Regards,
Ray @ Raylar
06-20-2012, 07:59 PM
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the ecm will have sticker under clear cover. it will have couple lines, that tell engine and what program is loaded. i think dealer has to burn most current program to comply with epa regs. i have seen some boats have problems with the bp "invigorate additive"
06-20-2012, 08:32 PM
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Just a little bit of info from my past experiences....
I too have a 2003 496 mag and I am not the original owner. I called Mercury direct with my engine serial number and the serial number off the ECM. They told me it was one that did NOT get reflashed. Mercury offered to reflashed free of charge (other than shipping). Once they entered my info in their database they told me to take the ECMmto my authorized Mercury mechanic and have them send the ECM into Mercury. They will not accept it directly from the consumer. In my case I was in a hurry an couldn't get Mercury to commit to as narrow time frame, so I opted to send my PCM to Dustin at Whipple for a stage II flash. There are some performance gains that can be gained by taking advantage of the rich fuel curve. The major increase was in midrange torque, not so much on the top end. Also because of the advanced timing curve Whipple uses in the stage II flash my idle changed to a much lumpier sound. (I will post YouTube links of before and after). However the stage II requires a 120 t-stat and premium fuel to eliminate detention, which will kill the hyper pistons in the 496s. So with a cooler T-stat and premium fuels, there will be some soot present after the stage II.
Once I had the flash done, my soot did decrease quite a bit. However, my problem went much deeper. Thanx to Rayar, it was brought to my attention early 496s had crappy intake gaskets that would pull oil in from the valley when under high vacuum.. After doing a few plug checks, and other diagnostics it was determined my intake gaskets were bad and my soot, was actually oil... I will also post a link to that thread.
Good luck to you in your quest for a soot free 496. I know it can be very frustrating. I would start by looking at your spark plugs. I learned this from experience. If you plugs are brown and show signs of oil, then you may have the same issue I had. If your plugs reflect a rich condition, I would contact mercury with you serial numbers.
LISTEN TO WHAT RAYLAR HAS TO SAY. HIS EXPERIENCE WITH THE 496 IS QUITE EXTENSIVE. He saved me from removing a perfectly good 496 and dragging it all the way across town to the scrap yard. My frustration with the soot had reached its limits.mmsome soot will always be present with the 496, but mine was actually making my transom almost completely black after a day of running. It took hours to clean....
Links to follow.
I too have a 2003 496 mag and I am not the original owner. I called Mercury direct with my engine serial number and the serial number off the ECM. They told me it was one that did NOT get reflashed. Mercury offered to reflashed free of charge (other than shipping). Once they entered my info in their database they told me to take the ECMmto my authorized Mercury mechanic and have them send the ECM into Mercury. They will not accept it directly from the consumer. In my case I was in a hurry an couldn't get Mercury to commit to as narrow time frame, so I opted to send my PCM to Dustin at Whipple for a stage II flash. There are some performance gains that can be gained by taking advantage of the rich fuel curve. The major increase was in midrange torque, not so much on the top end. Also because of the advanced timing curve Whipple uses in the stage II flash my idle changed to a much lumpier sound. (I will post YouTube links of before and after). However the stage II requires a 120 t-stat and premium fuel to eliminate detention, which will kill the hyper pistons in the 496s. So with a cooler T-stat and premium fuels, there will be some soot present after the stage II.
Once I had the flash done, my soot did decrease quite a bit. However, my problem went much deeper. Thanx to Rayar, it was brought to my attention early 496s had crappy intake gaskets that would pull oil in from the valley when under high vacuum.. After doing a few plug checks, and other diagnostics it was determined my intake gaskets were bad and my soot, was actually oil... I will also post a link to that thread.
Good luck to you in your quest for a soot free 496. I know it can be very frustrating. I would start by looking at your spark plugs. I learned this from experience. If you plugs are brown and show signs of oil, then you may have the same issue I had. If your plugs reflect a rich condition, I would contact mercury with you serial numbers.
LISTEN TO WHAT RAYLAR HAS TO SAY. HIS EXPERIENCE WITH THE 496 IS QUITE EXTENSIVE. He saved me from removing a perfectly good 496 and dragging it all the way across town to the scrap yard. My frustration with the soot had reached its limits.mmsome soot will always be present with the 496, but mine was actually making my transom almost completely black after a day of running. It took hours to clean....
Links to follow.
06-20-2012, 08:40 PM
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Before stage II flash. http://www.youtube.com/watch?v=4Jph8HmoIn4&sns=em
After stage II flash. http://www.youtube.com/watch?v=VZWLZkTa_m0&sns=em
Recent thread on the 496 soot/oil related to intake gasket: http://www.offshoreonly.com/forums/g...lp-anyway.html
FOR THE RECORD. I AM IN NO WAY AN EXPERT NOR DO I CLAIM TO BE! I AM IN NO WAY SUGGESTING YOUR PROBLEM IS OIL RELATED. JUST PROVIDING SOME ADDITIONAL INFO IN CASE FUEL IS NOT THE CAUSE OF YOU ISSUE.
Good luck to you!
After stage II flash. http://www.youtube.com/watch?v=VZWLZkTa_m0&sns=em
Recent thread on the 496 soot/oil related to intake gasket: http://www.offshoreonly.com/forums/g...lp-anyway.html
FOR THE RECORD. I AM IN NO WAY AN EXPERT NOR DO I CLAIM TO BE! I AM IN NO WAY SUGGESTING YOUR PROBLEM IS OIL RELATED. JUST PROVIDING SOME ADDITIONAL INFO IN CASE FUEL IS NOT THE CAUSE OF YOU ISSUE.
Good luck to you!
Last edited by low_psi; 06-20-2012 at 08:48 PM.
06-21-2012, 01:55 PM
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Before stage II flash. http://www.youtube.com/watch?v=4Jph8HmoIn4&sns=em
After stage II flash. http://www.youtube.com/watch?v=VZWLZkTa_m0&sns=em
Recent thread on the 496 soot/oil related to intake gasket: http://www.offshoreonly.com/forums/g...lp-anyway.html
FOR THE RECORD. I AM IN NO WAY AN EXPERT NOR DO I CLAIM TO BE! I AM IN NO WAY SUGGESTING YOUR PROBLEM IS OIL RELATED. JUST PROVIDING SOME ADDITIONAL INFO IN CASE FUEL IS NOT THE CAUSE OF YOU ISSUE.
Good luck to you!
After stage II flash. http://www.youtube.com/watch?v=VZWLZkTa_m0&sns=em
Recent thread on the 496 soot/oil related to intake gasket: http://www.offshoreonly.com/forums/g...lp-anyway.html
FOR THE RECORD. I AM IN NO WAY AN EXPERT NOR DO I CLAIM TO BE! I AM IN NO WAY SUGGESTING YOUR PROBLEM IS OIL RELATED. JUST PROVIDING SOME ADDITIONAL INFO IN CASE FUEL IS NOT THE CAUSE OF YOU ISSUE.
Good luck to you!
