Vovlo 5.7 Tbi Boggs down on acceleration

[Tail_Gunner]

Becareful of one thing going lean. If obd did retune for 90lb injectors it will run lean maybe pop thru the tbi.

 

[smurg109]

I guess I can call old and ask , also vovlov tech offered to flash my ecu for free, I'm hesitant to send to Volvo penta? Any thoughts

 

[Tail_Gunner]

OBD is as good as it gets just let them know what you have. If they have already flashed it they should know the tune that's in the mefi...call them

 

[Glastron_V210]

If you can slowly raise the throttle and it powers up fine, but you snap the throttle open and there is poor response, check the throttle position sensor (TPS). It is responsible, along with the MAP, to provide fuel enrichment on throttle increase (Basically an electronic 'accelerator pump' from the carbed days).

Injector ratings are important, ie: x amount of fuel at Y pressure, because it tells you how much fuel will flow. I'm glad you got a re-map when going to the 350 to hopefully keep it from going lean. the formula for figuring out flow at a different pressure is sqrt(new pressure/old pressure)*old flow rate.

So it would be sqrt(29/13)*90lb/hour = 134lb/hour or so, so a 50% increase or so over the rating. But, as long as the ecm mapping is for a 350 with your air flow, compression and injector size and fuel pressure then you're good.

Really, if they are the same injector size you had before, and were successful with, you're fine.

Keep in mind though, that this rating is in no way the maximum that the fuel injector can take. Some high performance guys run over 50psi with no issues. Your 29psi should not cause any injector lockup.

Hope that helps,

Chay

 

[Glastron_V210]

Last thing, there is a way to adjust timing. You will have to read the manual and figure out how to put your system into 'base timing mode'. Some systems require a jumper, or to pull a connector off. Without beign in base mode, the ecm controls the advance and uses the map sensor to do vacuum advance, so you MUST be in 'base timing mode'.

Chay

 

[smurg109]

I workin on figuring out to get get it into base timing.....I had changed out both the map sensor and tps but nothing changed

 

[smurg109]

I have access to a marine scanner, what would I look at to check the map and tps on scanner??

 

[Tail_Gunner]

If you were running the tj-11s with a pefs fuel pump that is the problem your tbi is just trying to clear itself from a choke....bog is choking popping is lean...well most of the time..

Now as to sensors the ect could be playing a role here and the sensor has nothing to do with the temp gauge but for now i am sure the old injectors will clean it up. ECT run about 12 dollar's a oriely's
[h=1]BWD - Coolant Temperature Sensor[/h] [h=3]Part # WT3000[/h]

 

[smurg109]

The original injectors solved the problem, i replace the high pressure fuel,pump and put the original injectors back in and it is running great now....I think it was the injectors......thanks to all for the help, so nice to be motorboat in again.....thank you