Truck shuts off.

[broncopolanco]

My 1989 BII EB edition shuts off shortly after being turned on. It doesn't putter then shuts off. It just shuts off. I can turn it back on but a second or 2 later it shuts off again. Any suggestions?

 

[RonD]

Could be a few things.

EEC relay powers the computer(EEC), fuel injectors, and spark.
So if it is not staying closed after startup system would die, just like key was shut off.

Fuel pump relay, same issue, you should hear the fuel pump come on with the key then go off 2 seconds later, it won't come on again until engine rpms are above 500, so after startup, if relay isn't closing again engine will die within a few seconds.

Ignition switch, under steering column, it has a START and a RUN position, when you turn the key to START power connections change, when key returns to RUN contacts change again, because RUN is the normal contacts they could be worn down so power is being lost in RUN, EEC relay opens and engine dies.
Do lights on the dash go off like key is off or do they stay on like key is on and engine is off.

TFI ignition issue, older they get the more likely they will have a problem.
Good read here for testing: http://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml


Just to narrow things down, you could get some Starting Fluid spray(ether), then remove intake's air plenum(big air tube) have someone start engine and when it starts to die spray some starting fluid into the intake.

If engine stays running then fuel supply is being lost, but spark is working
If engine still dies then spark is being lost

 

[feellnfroggy]

to just completely die like that sounds like a grounding issue. when i tightened the starter wires on my new starter I allow the hot cable to rotate alil too far an it would ground out on bumps, it just killed the spark, no stuttering or anything. took me weeks to find it. check all your wiring. if it was air or fuel you would stutter a lil just on fumes. start with battery and starting system then check coils, etc.

 

[broncopolanco]

Thanks guy I'll look into it. So i left the truck alone for about a day. Came back to it started right up and stayed on. Drove it around a while then parked it. Came back periodically to start it up and it would stay on. No issue. Engine running smooth and quiet. However, today I go to start it up and it cuts back off after 2 or 3 seconds. I can hear the gas pump wrkng for a second or so after it cuts off.

 

[RonD]

Then is sounds like spark issue

TFI ignition issue, older they get the more likely they will have a problem.
Good read here for testing: http://www.therangerstation.com/tech...agnostic.shtml

 

[broncopolanco]

i had the ignition and everything replaced about a year ago.

 

[RonD]

I would do the testing.

If in doubt put some gas or starting fluid in the intake and crank engine, if it doesn't fire up it has no spark