6.9 help!!!

[rattlebox93]

i have a customer's truck that he says when it sits for like a week or longer it will start then die right away then he hits the key and it fires right back up and it is fine....any help would be greatly appreciated i know nothing about those older ford motors or standadyne pumps....he just replaced all the glow plugs and the glow plus soulnoid both batterys i think the truck doesent have that many miles on it it is a 86 250 4x4 auto if you need any of that info thanks in advance dj

 

[kas83]

Fuel Shutoff Solenoid sticky/weak. First instinct would be losing prime, but since it's starting so quick each time, I'd lean towards fuel being cutoff by the solenoid.

 

[rattlebox93]

ok thanks ill try that he has a electric fuel pump pushing fuel into the stock lift pump do you think that has anything to do with it?....i know my old ve pump like the back of my hand but these standadyne's are foren to me!

 

[kas83]

Are both fuel pumps operational? I'd bypass one or the other, makes no sense to have one running into the other.

Also, does it seem like it shuts off clean like turning the key off, or does it stumble and die? DB2's aren't overly complicated, just takes a little patience to get through diagnosis.

 

[rattlebox93]

both are operational he put the electric one on to ease the transition between fuel tanks he said it was hard to switch before the electric lp and yes it does shut right down no stumbling

 

[roughneck0913]

run a jumper wire to the positve on the syloniod and see if it stays running after that?

 

[kas83]

both are operational he put the electric one on to ease the transition between fuel tanks he said it was hard to switch before the electric lp and yes it does shut right down no stumbling

Gotcha, and definately shutoff solenoid/electrical related.

run a jumper wire to the positve on the syloniod and see if it stays running after that?

Bingo. At least that way you can know that there is a short somewhere, and can look into the wiring.


It might also be in the key switch. Watch the radio when you start it the first time. Does the radio also shut off? Or any other keyed 'on' accessory will work. If the truck dies at the same time as an accessory shutting off, it could be the key switch. I had this problem in my 90 F250 7.3, it would fire fine, when I'd let off the key to return to the 'on' position, it would die immediately. It wasn't 'overreturning', or shutting off, but something inside was haywire and shorting it out. Would do this 2 or 3 times each start. Tried a known good keyswitch, and no more problems. Hope this helps.