Detroit Diesel 8V-71 Start Problem

[treeplanter]

Hi,

My 71 GMC 5305 8V-71 needs a burst of starting fluid to fire up after it has been sitting for a few days, otherwise it wont start up.

She will start fine when engine has been running-- don't know how many miles on her.

Any thoughts on this problem?

[dickandlois]

By chance do you have glow plugs. That being the case check for a blown fuse.

Intake heaters are controlled by the ECM. so a corroded connection on the 12 volt supply wiring at any of the connections can reduce heater temps.

Rich.

[DieselGuy]

Hello after working on these engines for over 35 years I may be able to help you. I would need to know hrs or miles on the engine. The engine doesn't have glowplugs its a 2cycle needs good compression to start, those engine were famous for broken compression rings even when the engine is totally worn out if you can start it it would still run.My guess it would need a compression test of every cylinder to find out what the compression is.

Installing new injectors into a old engine is not a good idea also you could remove the airbox covers and look inside at the pistons and rings. Also after few days of setting it may loose its prime but using staring fluid will addit your engine to it not a good idea as lot of starting fluid will raise compression to over 800 PSI normal is 520 PSI on a N engine .

If you loose your prime after sitting for a few days I would look on the primary side of the fuel system loose fittings loose filter can, that all starts from tank to primary fuel filter from there to fuel pump only, after it leave the fuel pump the fuel is under pressure and will leak fuel not suck air like primary side will. Also your engine doesn't have glow plugs or intake heaters or a ECM its a mechanical engine .Hope this helps I supplied my email if you need more help. mar02@hotmail.ca. name is Michael.