this is the final straw in a set of odd problems.
When i start my truck it runs for about 10 seconds then dies. if i hold my foot on the gas just a little for about 30 seconds it will stay running but the idle is rough and inconsistant. My check engine is on so i plan on putting an OBD1 decoder on it but just wanted to see if anyone had any ideas.
Thanks.
89 K5. 350 stock. 4x4

 

Just to throw this out there, when was the last time you did a full tune up? Plugs, wires, cap & rotor?

If recent, then it sounds like there may be a problem with the EGR system or a vacuum leak...

 

tune up was pretty recent.
this all started when instead of idleing down it would idle very high and was so high i didnt dare put it into gear so it hasnt seen much road time recently.
ive thought of a vacuum leak as well but i dont know where it would have come from. i parked it a few months ago and havent touched since and it ran fine then so i dont understand.
thanks.

 

A lot of vacuum leaks originate at the throttle body gasket. I'd take an unlit propane torch and direct it around the base of the throttle body and around any other areas that may be suspect for leaks. If the RPMs rise, then you've found your leak.

 

ok cool ill give it a try Thanks.
only one question though. i dont know if the trruck has a sensor for the vacuum pressure and the check engine light is on and wasnt until now.

 

well this whole things went from bad to worse. i got an OBD1 decoder and a propane torch and was headed out to try a few suggestions out. now the truck doesnt even start so im very stuck.
im not quite sure where to start, this came up out of no where.
any suggestions? besides the fuel pump ive already thought of that one hehe
Thanks

 

Could be as simple as a dead battery/alternator. Have you tried testing either of those yet? If you don't have a battery charger take your battery into Advance Auto Parts and they'll charge it and test it for you at the same time. Give that a try and see if it helps at all.

 

the battery was replaced about a month ago. as far as the alternater goes, it puts out a steady 14 amps. it rattles and makes some odd noices but as far as i can tell its working.

 

Check your battery terminals. Make sure they aren't corroded. Does it roll over? If it is rolling over and not firing. listen to see if you hear the fuel pump turning on when you turn the key on. If you here it turning on then it isn't your fuel pump.

 

it does roll over, or it did. the battery is dead now thanks to trying to start it. the terminals are nice and clean.and the fuel pump does make the same noise it always has when i turn the key to the on position.