Whats the worst you've seen ether do to an IDI?

[fsr7]

I finally picked the truck up yesterday - put a glow plug in it, threaded right in. Turned the key on and started testing things - strangely enough, the glow plugs had power going to them 100% of the time, even after the indicator light went off. Bad controller, maybe? GP's are probably shot, so I just disconnected that system. Gave it a shot of ether, the thing fired right up - smoked like hell 30 secs, then settled down into a slight white haze at idle. It definitely had some kind of internal knock, and I couldn't really source it out from cracking injector lines, so I pulled all the injectors to put a new set in. Cranked it for about 30 secs while the injectors were out, figuring it might blow something out if there was a broke off GP somewhere. Got the new injectors in, fired right up, runs smoother but still has the knock. It sounds like a top end deal, I haven't decided if I'm going to try to fix it or part it... hmm. Anyways, it was a pretty productive day yesterday - spent $1650, got the '94, got a '90 2wd f350 ex uhaul 14' box truck NA 7.3 with a decent miss but still drove itself 40 miles home, and a complete running NA 6.9. I'll post some pics when I get back to the shop.

 

[hesutton]

Yeah, the GP controller on the '83-86 6.9's tend to fail in the "ON" position and fry the glow plugs. Sounds like that's what's happend in you case.

Have you taken the valve covers off to see if you can track down the knock you are hearing at the top of the motor? Could be a rocker, pushrod, valve springs, valve........


Heath

 

[fsr7]

This is on the 1994 that I picked up yesterday - I don't know if they were notorious for gp control failures, the system worked fine on a '93 I used to have. I have not pulled the valve covers yet - I may get to that today - not really looking forward too it though

 

[hesutton]

This is on the 1994 that I picked up yesterday

OOOOHHHH. Whoops, I thought it was on the '86. Nah, the solid state system on the '94 usually doesn't fail that way, but it's not impossible.

Heath

 

[GREASE FIRE]

worst i've seen from either is "vapor"locked not sure if that's what you actually call it with either but you get the point.

what exactly is vapor locked? i have heard the term but don't know what it means/what it does/how much damage, etc.

thanks,
paul

 

[460429_freak]

I know it's a long shot...... pull the valve covers I know the older 6.9 would break the rocker arm (or go through the top of them) and being either locked maybe just maybe a bent push rod....

 

[MIDNIGHT RIDER]

what exactly is vapor locked? i have heard the term but don't know what it means/what it does/how much damage, etc.

thanks,
paul

"Vapor lock" is an occurrence where a "vapor", such as plain old air, gets trapped in a train of fluid, such that the vapor prevents the movement of said fluid.

Also, liquid fuel can become heated until it becomes a gas, thus "vapor", and fool an engine into thinking there is no fuel there.

The term is so often mis-used that it has gathered a host of meanings.

A common mis-use of the term is describing what takes place when the vent gets obstructed on the fuel-tank of a running engine, the engine runs until the vacuum in the tank over-rules the suction of the lift-pump, the engine dies from lack of fuel and it wrongly gets called "vapor-lock".

http://en.wikipedia.org/wiki/Vapor_lock

 

[69dieselfreak]

does anybody know what size threads the glow plug hole is in the head is just wondering and where i could i get a tap if i couldnt find one off of snatch-off (snap-on) or matco