Volvo Penta 4.3 GI Stalls Under Load

[robhay107]

Hi all

I have just picked up a regal with a Volvo Penta 4.3 GI (2000) that has been sitting for a few years doing nothing, on first outing i noticed that i could tick over fine under 2000rpm but as soon as i try to increase the revs the engine seems to try and stall, backfires and blows out a little black smoke, if i keep it below 2000rpm it runs fine. I have taken into a workshop whereby they did a service and advised to drain all the old fuel as this would be causing the issue. New plugs and filters fited (a big bill later) and fuel drained it still has the same issue! I have even run the engine on an outboard tank of clean fuel and it does not impove

would welcome any advice on this

 

[bnicov]

Re: Volvo Penta 4.3 GI Stalls Under Load

The carb is probably in need of a rebuild. There is likely a buildup of junk in it since whatever fuel was in it when originally stored dried leaving varnish deposits. The kit is around $50 and can be done by a fairly competent do it your selfer.

 

[robhay107]

Re: Volvo Penta 4.3 GI Stalls Under Load

Thanks for taking the time to reply, it's a fuel injected system, Is it possible that the high pressure pump is gunked up or maybe somewhere up by the throttle housing/injectors

 

[robhay107]

Re: Volvo Penta 4.3 GI Stalls Under Load

anyone else have any advice they could offer?

 

[Technologic80]

Re: Volvo Penta 4.3 GI Stalls Under Load

Test your fuel pumps and their pressures. No power over 2500RPM's is usually indicative of a high pressure fuel pump problem.

There was a big problem with the Volvo's. See, a supplier thought it would be smart to paint the INSIDE of the fuel pumps. Well, you can see where Im going with this. The gas would work as a solvent (especially gas with E10) and paint chips would clog the inlet screens of the pumps. Removing the pumps and checking the little inlet screens would be my first step. If the screens are clean, reinstall the pumps but leave 1 of the pumps wiring harness disconnected. Turn the key. Does it go "BZZZZT" for a few seconds? If so, its functioning at least. If it doesnt, its bad.

However, its still possible that it can bzzzzt and prime, but not create enough pressure. The smartest way to test this is to rent a fuel pressure gauge or buy one - one that reads up to 100psi - and check it via the schrader valve near the fuel pumps. Low pressure should be 4-8psi and the high pressure should be 55psi+. From what Ive read, youll only get low pressure psi when you turn the key. So 4-8psi right away. Then, when the engine fires and starts, the high pressure pump activates and you should have consistent 55psi+.

 

[robhay107]

Re: Volvo Penta 4.3 GI Stalls Under Load

This is a great piece of information.

Many thanks, you may well have saved me a lot of $$!!

 

[robhay107]

Re: Volvo Penta 4.3 GI Stalls Under Load

have had the fuel pumps stripped downand cleaned and both appear to be at correct pressure, engine still running a little rough when come off WOT, like its being over fuelled. Removed the MAP sensor and it performs like a different craft. put a new MAP sensor on it an dit makes no difference!

 

[Technologic80]

Re: Volvo Penta 4.3 GI Stalls Under Load

OHM out your temperature coolant sensor.

If its skewed, it will tell the engine its a different temperature (COLD) and provide a super rich mixture, which can result in the problems you are experiencing.