1994 5.8l Fi Volvo hard to get started after warmed up

[Todd157k]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

item 69 in above link

 

[RodeoTrent]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

okay, sitting on the front of the houseboat, finally got internet service, i replaced the engine block tempature switch, apprently it controls the guage on the dash it shot up to almost 240 on the dash but the enigne wasnt over heating, put the old one back in and now its holding at 150 or a hair over. i did run the engine with the cover off, and could not get the problem to re create, could this be an evaporation fo fuel issue now? get back to me quick while im at the boat and test ready, ps. i did not install the air charge sensor yet. becuase i havent got it to have starting trouble since the engine cover was off during testing

 

[RodeoTrent]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

okay so apparently, it has to sit longer than i was letting it sit during testing been back her for about 20 mins or so and tried it again and it did the same thing, but we put the engine cover on it after we put it back in the slip.....I HATE EFI grrrrr

 

[RodeoTrent]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

alrighty apparently the air charge sensor is not the same as the one found in a 1994 ford pick up truck the sensor looks different and the plug is a little off other than that it ooks the same, also should there be water inside when i remover it, i could see water down in the intake manifold

 

[Todd157k]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

alrighty apparently the air charge sensor is not the same as the one found in a 1994 ford pick up truck the sensor looks different and the plug is a little off other than that it ooks the same, also should there be water inside when i remover it, i could see water down in the intake manifold

no water should be there. How much is? Is the manifold cracked? See steam?

 

[RodeoTrent]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

after doing some research the sensor on the front right side of the manifold is a coolant temp sensor, it is the one that the map sensor uses to compute its a/f ratio mix and other things by measuring the temperature of the water. i bought the air charge sensor , where it goes i have no clue, im going to check the pressure regulator, and the fuel pressure next, i work in HVAC, and i know that lower pressure means lower boiling points, in turn i think that the fuel in the line is evaporating after it shuts off, my reason for believing this is that u have to let the boat sit for 20 plus minutes before starting problem occurs, if its only 5 or so mins the boat fires up normal

 

[Todd157k]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

The MAP sensor has nothing to do with water. It's Manifold Absolute Pressure. If there's water, it's f'in up the sensor.

from wiki:

A manifold absolute pressure sensor (MAP) is one of the sensors used in an internal combustion engine's electronic control system. Engines that use a MAP sensor are typically fuel injected. The manifold absolute pressure sensor provides instantaneous manifold pressure information to the engine's electronic control unit (ECU). The data is used to calculate air density and determine the engine's air mass flow rate, which in turn determines the required fuel metering for optimum combustion (see stoichiometry). A fuel-injected engine may alternately use a MAF (mass air flow) sensor to detect the intake airflow. A typical configuration employs one or the other, but seldom both.

 

[RodeoTrent]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

thats what im saying , this coolant temp sensor, is part of the MAP sensor sensors, it retrieves information from multiple sensors then computes a reading for the ECU i did some research on this issue with people with 5.8l trucks having these issuse which are more common (theres more 5.8l Fi in automobiles than boats) and a few people said they had solved the problem with the coolant temp sensor , it was sensing cool water all the time when the enigne had actually warmed up requiring less fuel than the computer was told

 

[RodeoTrent]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

well i put the new coolant temp sensor in......No change what so ever....did notice if u put the boat in neutral before you start and give it full gass it starts fine but u gotta yank it back to idle when it starts

 

[JustJason]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

Hey Trent, any chance you can post your full model and serial numbers?

 

[Don S]

Re: 1994 5.8l Fi Volvo hard to get started after warmed up

Since you have a 94, and a VP/OMC joint venture, and there was no such thing in 93, I would guess you have an MD model.
Below are the OEM service manuals for the MD model, perhaps they can help you some.

http://www.4shared.com/dir/14518511/785d67cc/MDsharing.html