13b Turbo Post Ignition

[zaxxon]

My 87 BJ74 runs for a while after I have turned the key off. What could be causing this and how can I fix it. Is is a fuel problem. What type of maintenence should I be doing on my fuel system.

Thanks all

 

[Greg_B]

My 87 BJ74 runs for a while after I have turned the key off. What could be causing this and how can I fix it. Is is a fuel problem. What type of maintenence should I be doing on my fuel system.

Thanks all

It could be your VSV is getting dodgy. You 13BT shuts down by a shutter just above the intake manifold. When you turn off your key, power is removed to the VSV and it allows vacumn to the shutter pot, which closes the shutter, starving the engine of air.

It could also be that someone leaned on the shutter pot, bending it over, so it can not activate fully and close the shutter. Make sure the pot is horizontial.

Your VSV is located on the engine block, on the left rear side, in front of a frost plug and right below the 13B. Other then simply getting old and failing, they seem to not like getting wet. Best thing is to move it to the firewall, high, and coat the interior of the connection with dialectric grease, and coat the outside too with anything to improve water resistance.

You can bypass the VSV if it totaly fails (till you get a new one) and simply shut down the engine by hand (pull the lever on the bottom of the pot up, closing the shutter by hand). The default position for the shutter is open.

Some say the best thing you can do for your fuel system is run biodiesel. If that is not in your area, then make sure you use a good fuel conditioner/centane boost/lubricity/anti-gel/anti-alge additive in every tank. If your injectors have not been serviced, then that would be wise so you have a baseline. Change your fuel filter at least once a year. Some have reported improvement by having the pump timed. And change your air filter at scheduled intervals so the engine is not starved of air.

hth's

gb