Vovlo 5.7 Tbi Boggs down on acceleration

[smurg109]

I've replaced the plugs wires cap,rotor, coil, high pressure fuel,pump, fuel,pressure is at 29lbs on high side, good compression all cylinders at 170 lbs, tried to,adjust distributor but can't adjust base timing apparently ....not sure if it is fuel or spark....I replaced the two injectors and cleaned the throttle body assembly, the fuel pressure regulator is a spring and diaphragm....replaced the temp,sensor and iac valve and map sensor.....it runs ok if I take the throttle very slow but if not it wants to bog down...

 

[alldodge]

I've replaced the plugs wires cap,rotor, coil, high pressure fuel,pump, fuel,pressure is at 29lbs on high side, good compression all cylinders at 170 lbs, tried to,adjust distributor but can't adjust base timing apparently ....not sure if it is fuel or spark....I replaced the two injectors and cleaned the throttle body assembly, the fuel pressure regulator is a spring and diaphragm....replaced the temp,sensor and iac valve and map sensor.....any ideas would be appreciated....

:welcome: to iboatsl
Were going to need a year or more engine info. There are a lot of 5.7 out there. Fuel pressure at 29 sounds a bit low from my take

 

[smurg109]

The boat is a 2000 regal commadore, the engine is a 5.7 that was replaced about four years ago, it has the vortex heads...fuel pressure is right where the book says it should be at 29lbs.....

 

[alldodge]

Was the engine replaced with a long block and used all previous stuff off old engine or a full drop in 2010 or 2011 version?

Has the engine been running fine previously?
If all OK previously then has anything been done this season?
Did it act up all at once or did something happen?

 

[smurg109]

It was replaced with a long block, everything from the old engine was put in new long block, was running very rich, I had computer re flashed and that fixed the rich problem, I then got a throttle body rebuild kit and cleaned and put in new injectors, the boggin is new this season....

 

[smurg109]

Engine was replaced in 09

 

[alldodge]

We could really need to know if there are any codes being thrown.
Without that check plugs to see what they look like. Are you getting a good 12V from the alternator? Check grounds
A compression test would be next, sure its a new engine but not knowing if any codes are showing up is an issue

 

[smurg109]

No codes are present, compression is 170 all cylinders, I don't know about alt volt but I will check that next...

 

[alldodge]

Pull the vacuum line off the map sensor, install a tee and measure your vacuum

 

[Tail_Gunner]

It was replaced with a long block, everything from the old engine was put in new long block, was running very rich, I had computer re flashed and that fixed the rich problem, I then got a throttle body rebuild kit and cleaned and put in new injectors, the boggin is new this season....

Could you explain this in more detail why the reflash it was running rich??? as long as you installed a roller cam and vortec heads there should have been no need for a reflash..who flashed the ecu. and as to injectors they are very spefic can you post the model number's???

A 2000 5.7 used color codes black and yellow delphi injector's penta number 3857398 the color code's equate to 55lb injectors at 13 psi...Now with all that is this a 5.7 GI PEFS or was it a PEFS.

 

[smurg109]

Was my buddy's boat and he cracked the block, switched from the 5.0. To 5.7 , all old stuff put on new long block, when I bought it it was running pig rich, the marina that put in the long block put in an ecu flashed from Arizona speed and marine, not sure if the marina had it lYing around or purchased it...either way this thing was running way to rich, so I sent the mefi 3 ecu to obd diagnostics in redonda beach California, and the fuel issue is much better.....lazy year it seemed to lack power, this year it is now bogging down anytime I throttle unless I move it very slowly....I did have the throttle body assembly off and cleaned it and the diaphragm was intact when I put it back together with the spring in the pressure regulator assembly....I purchased new injectors from rock auto bc one of mine was not spraying a good cone, I have since sent out the original injectors and had then cleaned and flow tested, I think I may throw them back in to be safe....
What should the vacuum be on the map sensor??

 

[smurg109]

Last year not lazy...fyi

 

[smurg109]

And it's a GI, throttle body injection

 

[Tail_Gunner]

Was my buddy's boat and he cracked the block, switched from the 5.0. To 5.7 , all old stuff put on new long block, when I bought it it was running pig rich, the marina that put in the long block put in an ecu flashed from Arizona speed and marine, not sure if the marina had it lYing around or purchased it...either way this thing was running way to rich, so I sent the mefi 3 ecu to obd diagnostics in redonda beach California, and the fuel issue is much better.....lazy year it seemed to lack power, this year it is now bogging down anytime I throttle unless I move it very slowly....I did have the throttle body assembly off and cleaned it and the diaphragm was intact when I put it back together with the spring in the pressure regulator assembly....I purchased new injectors from rock auto bc one of mine was not spraying a good cone, I have since sent out the original injectors and had then cleaned and flow tested, I think I may throw them back in to be safe....
What should the vacuum be on the map sensor??

TBC

 

[alldodge]

What should the vacuum be on the map sensor??

Vacuum should be a steady 15-22 inHg at idle

 

[smurg109]

Original engine info
5.0GI PEFS
4110199393
3869057

 

[Tail_Gunner]

If you purchased the tj-11 injector from rock auto they are rated @ 90lb's at 13psi, you marine fuel system produce's 30 lbs those injector's would both flood and go static (full on stuck) at that pressure. Now if your told OBD that you put 90 lbs injectors in there and they flashed a tune for them well they should work but i highly doubt they did that. Put your old injectors in and things should settle down. The correct injector's would be a 55/60 lb auto injector preferably for the 94/95 454 from gm that yr model a 30lb fuel pressure.,.

 

[smurg109]

I checked alternator and it is good....
I also,put original injectors back in but did not take it out for a run but will Tomorow and post.....thanks to help

 

[smurg109]

I Did buy the tj11 injector, I saw 90lb but didn't see any info,on pressure, hope that does it, will know tomorrow

 

[smurg109]

Will try to check vacuum on map also