2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

[Rotorpilot1969]

I have a rinker 270 bravo setup and have just placed a new engine in this boat. Fuel tank was in bad condition lots of water and trash but think I have cleared the tank up enough to look at another problem. Boat has new fuel pump and regulator new injectors too. I read an old thread in here were the guy had same setup and his vst had become clogged. I don't think my boat has vst? I have a fuel cooler and a regulator that has a vent tube or vacuum tube that I believe is suppose to run up to the tbi but mine doesn't because I wasn't sure where the hoses went and didn't think that was such a big deal. Boat starts great revs great runs nice until I hit that 3 k RPM mark and boat just bogs and will not advance and of course I can never plane. If I back off a little the boat acts like its bad fuel and will try and clear up but doesn't. I almost think the boat is in a loop or limp mode. Could anyone tell me if I have a vst and where it would be or look like ? Also does anyone know where the vent vacuum hose runs and plugs in from the regulator near the pump. I believe it comes from the reg. down near the pump into a tee and one plugs in the intake or spark arrester and another somewhere else on the intake.

Thanks for any help

 

[alldodge]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

I have a rinker 270 bravo setup and have just placed a new engine in this boat. Fuel tank was in bad condition lots of water and trash but think I have cleared the tank up enough to look at another problem. Boat has new fuel pump and regulator new injectors too. I read an old thread in here were the guy had same setup and his vst had become clogged. I don't think my boat has vst? I have a fuel cooler and a regulator that has a vent tube or vacuum tube that I believe is suppose to run up to the tbi but mine doesn't because I wasn't sure where the hoses went and didn't think that was such a big deal. Boat starts great revs great runs nice until I hit that 3 k RPM mark and boat just bogs and will not advance and of course I can never plane. If I back off a little the boat acts like its bad fuel and will try and clear up but doesn't. I almost think the boat is in a loop or limp mode. Could anyone tell me if I have a vst and where it would be or look like ? Also does anyone know where the vent vacuum hose runs and plugs in from the regulator near the pump. I believe it comes from the reg. down near the pump into a tee and one plugs in the intake or spark arrester and another somewhere else on the intake.

Thanks for any help

A serial number would help. You shouldn't have a VST, they stopped putting them before 2000. The Vacuum line goes from the pressure regulator to the intake or throttle body and it is needed. The vacuum line tells the regulator to increase/decrease fuel rail pressure to the injectors.

You should have a knock sensor on the starboard side of the engine, above the starter and below the exhaust manifold. Pull the connector off the knock sensor and see if you get power back. If you do slow back down, and put the knock sensor back on. Then go check your timing before you damage the engine. If this does nothing let us know.

 

[dubs283]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

The vacuum line tells the regulator to increase/decrease fuel rail pressure to the injectors.

the pressure regulator has nothing to do with increase or decrease of fuel pressure, all it does is help even out the fluctuation in fuel pressure due to the varying pulse width of the fuel injectors. the regulator needs vaccuum applied to it to work properly to help maintain even pressure at the injector rails

if there is fuel present in the vaccuum line, the regulator has failed, also when testing pressure - remove vaccuum line pressure rises, apply vaccuum to the regulator pressure goes down/regulates to the spec value for the regulator

to op:

have you checked fuel pressure?? and vaccuum??

have you inspected the water separator??

 

[alldodge]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

the pressure regulator has nothing to do with increase or decrease of fuel pressure, all it does is help even out the fluctuation in fuel pressure due to the varying pulse width of the fuel injectors. the regulator needs vaccuum applied to it to work properly to help maintain even pressure at the injector rails

QUOTE]

Only on early MEFI-1 systems had two pressure regulators
Quote from Merc Manual No 24: Early versions of the MEFI-1 systems had a second regulator mounted in the fuel rail. This regulator does not control system fuel pressure. It is used to dampen fuel system pulsation only. Later versions of the MEFI-1 and the MEFI-3 have this regulator removed from the fuel rail.

Another Quote from Merc Manual No 24: MEFI 1 and MEFI 2 Only: The pressure regulator is a diaphragm-operated relief valve with
fuel pump pressure on one side, and regulator spring pressure and intake manifold vacuum on the other. The regulator?s function is to maintain a constant pressure differential across the injectors at all times. The pressure regulator compensates for engine load by increasing fuel pressure as engine vacuum drops. The fuel pressure regulator is located on the cool fuel assembly.

Fuel pressure should be 30psi

 

[dubs283]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

i should have worded my response differently, yes the regulator does control increase/decrease slightly, but it has more to do with evening out the pressure due to the injectors opening and closing than a noticable increase in pressure

the true test is to verify the pump can provide adequate pressure by testing the pressure with the vacuum line removed and recording the reading, it should be roughly 40-45 psi, and the decrease when vacuum is applied to the regulator

however there is more information you aren't providing, there can one of three different regulators used in the system (cool fuel) depending on the color marked on it and they all have different specs for fuel pressure

fact is, without a serial number its anybodys guess as to what fuel system and ecm the op has

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

Thanks for all the good replies. I can't test fuel pressure until later this week. I'm not sure of serial number because it's a ATK reman. But I'll look. It has a cooler on it and a fuel water separator that isn't too dirty but tank did have a lot if water in it that I've removed. Gas is clean. Still some deposits though. Is there a screen in or near the fuel pump that may have gotten clogged? I can't really remember when I installed it last year. Also could I install another inline fuel filter maybe in front of the water fuel separator just for extra protection. I will also remove the knock sensor later this week when I can return to the water. I will keep you posted as more results are known... thanks

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

Ok, I put some sta-bil in the tank today and also adjusted timing and on the water today I unplugged several different plugs trying to narrow down my issue. KS sensor seemed to make no difference but did see some short term improvement when I unplugged the oil sensor but it came back to the same ole issue. Plugged all sensors back in and unplugged my tps sensor and the boat ran high idle and of course ran rich and smoked a bit but actually ran fairly well. I was able to get on plane a few times and obtained 3400 rpms. A few differnt times the boat would try to clear up and take off then I'd hear a knock sound and miss. Is this related to the KS sensor? Oil is good temp is solid at 160. All components in this engine are new from pump to cap wires plugs and injectors. I really think I have a gummed up tps and some crappy fuel and maybe a few sensor issues but for the most part I think the motor is solid as I mentioned its brand new reman ATK. I did pull a sensor off the TB next to the fuel intake and it was stopped up with some gunk and it helped after cleaning.

I never heard this boat run prior to purchase because the lady let it set in a saltwater slip for a few years unattended. Old motor would have run but everything needed replaced so I just pulled it and went ahead and put in a new motor. Tomorrow I will pull all sensors and clean and try again. I have only two main concerns 1. The knock noise and 2. The used outdrive I put on this boat may have the wrong gear ratio because original was salt water damaged with holes in the foot. Can I split the unit and determine the ratio? I never verified ratio I just took the mans word it was the ratio I needed. I can't remember what I needed now. I have it written down though. Props are original.
I'll post again after next run.
Thanks for the help

 

[alldodge]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

Ok, I put some sta-bil in the tank today and also adjusted timing

What did you adjust the timing to, and was the engine put in base timing mode when this was done?

and on the water today I unplugged several different plugs trying to narrow down my issue. KS sensor seemed to make no difference but did see some short term improvement when I unplugged the oil sensor but it came back to the same ole issue.

Unplugging other sensors will cause the engine to throw mode codes. The codes can cause other issues.

Plugged all sensors back in and unplugged my tps sensor and the boat ran high idle and of course ran rich and smoked a bit but actually ran fairly well. I was able to get on plane a few times and obtained 3400 rpms. A few differnt times the boat would try to clear up and take off then I'd hear a knock sound and miss. Is this related to the KS sensor?

If your hearing a knock or miss you probably have a fuel or ignition issue. The KS retarders timing if the sensor picks up a knock to protect the engine. This is why if the KS wire was removed while the sensor was picking up a knock, the engine would rev up. Yours didn't do that so it probably is not picking up a knock.

Oil is good temp is solid at 160. All components in this engine are new from pump to cap wires plugs and injectors. I really think I have a gummed up tps and some crappy fuel and maybe a few sensor issues but for the most part I think the motor is solid as I mentioned its brand new reman ATK. I did pull a sensor off the TB next to the fuel intake and it was stopped up with some gunk and it helped after cleaning.

If you have bad gas it cannot be made good by putting stabil or anything else in it. It has to be drained out and replaced.

I never heard this boat run prior to purchase because the lady let it set in a saltwater slip for a few years unattended. Old motor would have run but everything needed replaced so I just pulled it and went ahead and put in a new motor. Tomorrow I will pull all sensors and clean and try again.

Don't do that

I have only two main concerns 1. The knock noise and 2. The used outdrive I put on this boat may have the wrong gear ratio because original was salt water damaged with holes in the foot. Can I split the unit and determine the ratio? I never verified ratio I just took the mans word it was the ratio I needed. I can't remember what I needed now. I have it written down though. Props are original.
I'll post again after next run.
Thanks for the help

If you have a knock you need to adjust the timing by setting it in base timing mode.

To determine ratio pull the drive and rotate the drive shaft and count the rotations at the prop. If the ratio is to high it will cause some performance issues but not what you seeing with it missing.

Need to get or use a scanner to check for codes, also check fuel pressure. An automotive fuel pressure gauge that reads to at least 50 psi will work

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

What did you adjust the timing to, and was the engine put in base timing mode when this was done?


Unplugging other sensors will cause the engine to throw mode codes. The codes can cause other issues.


If your hearing a knock or miss you probably have a fuel or ignition issue. The KS retarders timing if the sensor picks up a knock to protect the engine. This is why if the KS wire was removed while the sensor was picking up a knock, the engine would rev up. Yours didn't do that so it probably is not picking up a knock.


If you have bad gas it cannot be made good by putting stabil or anything else in it. It has to be drained out and replaced.


Don't do that



If you have a knock you need to adjust the timing by setting it in base timing mode.

To determine ratio pull the drive and rotate the drive shaft and count the rotations at the prop. If the ratio is to high it will cause some performance issues but not what you seeing with it missing.

Need to get or use a scanner to check for codes, also check fuel pressure. An automotive fuel pressure gauge that reads to at least 50 psi will work

The high rev was from unplugging the tps. Can I clear the codes and start over without a tool or handheld? I also agree the ratio isn't causing my main issues. I still have at least 50 gallons of fuel and near impossible to drain this tank via its location. I'll just try and run most of it out I did set ECM to base mode but only guessed at location of 8 degrees. My inductive TL doesn't have a dial so I need to make a timing tape to be more accurate. Once in base mode the engine automatically goes to 1300 rpms as designed. Will disconnecting the battery for a while clear my codes?

 

[alldodge]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

The high rev was from unplugging the tps. Can I clear the codes and start over without a tool or handheld? I also agree the ratio isn't causing my main issues. I still have at least 50 gallons of fuel and near impossible to drain this tank via its location. I'll just try and run most of it out I did set ECM to base mode but only guessed at location of 8 degrees. My inductive TL doesn't have a dial so I need to make a timing tape to be more accurate. Once in base mode the engine automatically goes to 1300 rpms as designed. Will disconnecting the battery for a while clear my codes?

You can clear the codes but only with a scan tool. Disconnecting the battery may delete them but not guaranteed. Most will go away on their own over time if the symptom goes away.

Setting the timing should be at 8 BTDC. Below is a link which shows how it is marked.
Boatinfo - Mercruiser Service Manual nr. 24 - 1998-2001 - Engines GM V8 305 & 350 CID

If you have the timing marked on the balancer and cannot see it because of paint, use some sand paper to bring the marks back

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

I've still not had a chance to return to the lake but I started having idle problems and discovered my TPS was bad. Doesn't happen often but it did to me. I pulled the injectors top plate too just to look and couldn't believe the sludge jelly crap I found. IAC started sticking too. I've replaced all sensors on the TBI even the injectors again. Does anyone know if all injectors are the same. I've read different threads and even changed out car motors and never experienced a injector difference with performance. I've heard big block injectors are used in my boat but I put a used set of small block car injectors in it and seems to run fine on the trailer not under load. Guess will will see

 

[alldodge]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

What is yor engine serial number?

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

What is yor engine serial number?

I really don't know and it's a new reman ATK so not sure if it would help.

Updated today : I was able to take the boat out today with some added fuel stable and 20 gallons of fresh gas and it's running better but not good. I did re route some plug wires and that made a big difference as some were touching. I have set reset advanced and retrarded the time some much I can almost do it by feel. I don't think this boat likes 8btdc for some reason. Next trip I will replace the fuel water separator and add some higher octane gas. I really hope my problem is strictly fuel. Today I was able to hole shot from idle to 3200 rpms fairly quickly and plane and top out my rpms at 3700. I've read this boats ideal cruise speed is around 3850 but I have no idea because I bought the boat not running. What is the max rpm range for my engine? Sorry the speedo isn't hooked up so not sure what it is. The boat towards the end of the afternoon was wanting to run as it would shunt in and out like a miss and it is still detonating knocking some.

 

[dubs283]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

depending on the type of ignition system you have you may need a shunt or service tool to properly adjust the timing, which may be why 8 degrees does not work well for it

if you post an engine serial number we can tell you proper engine info, it should be on the flame arrestor cover or ecm box cover

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

depending on the type of ignition system you have you may need a shunt or service tool to properly adjust the timing, which may be why 8 degrees does not work well for it

if you post an engine serial number we can tell you proper engine info, it should be on the flame arrestor cover or ecm box cover

I jumper a and b together when adjusting the timing. I will look on original block for a serial number.
Thanks. I just read top rpms for this engine is 4400-4800. I have a ways to go before I reach those numbers. I will also look at my cable to insure it's adjusted proper for wot thanks for the reply.

 

[dubs283]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

I jumper a and b together when adjusting the timing.

in place of a shunt??

 

[Rotorpilot1969]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

in place of a shunt??

Yes I would guess so... When I jumper AB together it revs up to 1300 rpms as it's suppose from my readings. Is there something else I'm needing to do? Thanks again for the help.

 

[alldodge]

Re: 2000 5.7 EFI BRAVO 3 fuel cutting out at 3,000 RPM

Yes I would guess so... When I jumper AB together it revs up to 1300 rpms as it's suppose from my readings. Is there something else I'm needing to do? Thanks again for the help.

That is the wrong way to do it for your engine. The AB connection is for TB-4 you should have a TB-5 setup. You need to connect a wire from the Pur/Wht wire (No 13) to ground.

 

[Rotorpilot1969]

Update: I still don't have a serial number to post because it can't be read from TB cover and original engine is in storage. However I went out recently with some good high grade fuel and boat stopped cutting out and seems to have cleared up but still can not achieve more than 32-34 hundred rpms. I bought this outdrive used and starting to wonder if the ratio is wrong? I'm going to start a new thread about this.

 

[MikDee]

If you're getting crossfiring, or arcing, you need to make sure you have resistor spark plugs in there to stop that! Typically AC- MR43T style plugs.