I have a Volvo 5.7 GSI TBI 280 Hp.When going from idle to WOT She bogs for about 30 sec. and the it's fine. If I go to WOT slowly She is fine. I have change Fuel pump, fuel filter, TBI unit and injectors, new cap, rotor, plugs, wires. Vacuum is 17 degrees. The top end RPM is 4800 mid range is good.
please HELP.
I would check for breaks in the vaccuum lines and the MAP sensor as these are usually the culprits for a bogging fuel injected engine. But then again Volvo has that funky dual High/low pressure fuel pump design that may be the problem. Did you replace the high pressure pump?
no but i did replace the pump that is next to the fuel filter, I did get a reading of 29 lbs off the high side. I check for leaks found none.
Chap I have a 2001 GSI that bogged bad from 1600 to 2400rpm I had it to three different shops before it was decided to try a NEW ECM. Not reprogrammed that had been tried already. This fixed my boat. Thanks to the good people at Village Marine lake ozarks MO. and Cobalt boats. Check fuel pressure as I recall it should be around 30psi everything on my boat was fine just the stupid computer.
Chap, does your boat act like it is missing out on two cylinders up until it gets going and planed out and then it runs o.k.??
Chap there is a Fuel/vapor reservoir on these volo
fuel pumps that has a vacuum line hooked to it and it goes straight up to the intake manifold just under the TBI. Sometimes the float mechanism in this reservoir gets clogged and allows it to get full of fuel and allows the engine to suck fuel up the vacuum hose and deliver un monitored fuel into the intake making it very rich until you are up and running and the engine can use the extra fuel. A Volvo Mechanic told me about this and it was checked on my boat. Additionally the Coolant Temp sensor can cause similar problems. Need a scan tool to check this.
john
my problem is under a load it seems like it has no power for a short time the it takes off, but the mid range is good.
You talked about the fuel reservoir the high pump was 29 lbs the book said it should be 29 +-2, I Plan on takeing off the reservoir and cleaning it out hoping to find soming inside.
Chap,
You may be able to connect a clear piece of hose to the reservoir up to the intake manifold and see if their is raw fuel in the line while idleing or have someone help and watch it when it running. It sounds like you have the exact same problem I did and from the hours spent by 3 different techs and the time I spent on the phone with Volvo its got to be one of these things. According to a Volvo tech they used to have a lot of problems with those reservoirs in the years that your boat was made. I will be interested to see what you find out,, hopefully not the ECM.
Hey Chap whats the Good Word???
John
Pulling the bout out this weekend hope to dig in to it next week i will let you Know
Gil
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