BJ74 won’t shut down

Joined
Jul 11, 2021
Messages
10
Location
Okinawa, Japan
Really need some help here,

Been chasing this problem for about a month. When I turn the key off, the truck drops down to about 200rpm but will never shut off. I have replaced the VSV, all the vacuum lines, the Venturi, and made new gaskets for the Venturi and intake heater. The vacuum pressure is good. If I use my hand to pull up on the vacuum idle actuator it’ll shut it off, and as soon as that happens I hear a little air sucking in somewhere. But, with the key the engine won’t turn off. I’ve sprayed starter fluid around all the seals for the intake and it never increases the idle, so no leaks I believe. Any ideas?
 
Joined
May 6, 2010
Messages
489
Location
Armstrong, Canada
Do you have an EDIC motor on this engine? Could be the EDIC is failing or has failed. Can't remember if they are adjustable or not, as it sounds like it is not quite cutting off the fuel all the way.
 
Joined
Jul 11, 2021
Messages
10
Location
Okinawa, Japan
Do you have an EDIC motor on this engine? Could be the EDIC is failing or has failed. Can't remember if they are adjustable or not, as it sounds like it is not quite cutting off the fuel all the way.
No, no EDIC. The 13bt shuts off air rather than fuel, but I think I may have found the problem. Spraying starting fluid on the intake side I found what may be the brand new intake manifold gasket to have blown out on one corner, broke the bolt trying to tighten it more. Waiting on parts and hopefully it’ll fix it.
 
Joined
Mar 10, 2019
Messages
802
Location
melbourne, Oz
careful tightening bolts on aluminium manifolds. maybe use more goop, I have been enjoying using hylomar blue, easy to apply, dries quick and much easier to remove than silicone.

does sound like air coming in somewhere.

how does the key shut off mechanism shut off the air without the edic? pic of suspect?
don't know the 3b

some folks install a pull cable to shut off air, like old tractors.
 

FJBen

SILVER Star
Joined
Apr 1, 2004
Messages
6,376
Location
Northern Colorado
careful tightening bolts on aluminium manifolds. maybe use more goop, I have been enjoying using hylomar blue, easy to apply, dries quick and much easier to remove than silicone.

does sound like air coming in somewhere.

how does the key shut off mechanism shut off the air without the edic? pic of suspect?
don't know the 3b

some folks install a pull cable to shut off air, like old tractors.
It’s a 13bt. Vacuum pulls down a valve which turn a “butterfly” valve with blocks all airflow shutting down the engine.

Usually it’s a leak which causes the valve to not close all the way and not shut off the engine.
 
Joined
Jul 11, 2021
Messages
10
Location
Okinawa, Japan
Yup... if the intake gasket is not the issue (sounds like it is the culprit) then grab a vacuum pump and check the actuator, and lines for leaks, and normal operation of the VSV.
I think it’s this intake gasket, vacuum pressure is good as it actually maxes out my gauge, and the VSV closes fully. Waiting on parts and hoping that the bolt broke rather than the intake manifold!
 
Joined
Mar 10, 2019
Messages
802
Location
melbourne, Oz
haha! yeah teaching my middle boy to drive the troopy, doing a good job stalling the engine releasing clutch too sudden. thankfully not in public , bit uncool
 
Joined
Jul 11, 2021
Messages
10
Location
Okinawa, Japan
Hey guys, just wanted to give an update! Replaced the intake manifold gasket and added some high temp spray sealant on it to hopefully help it not blow out again. While I had it off I went ahead and gave the injection pump a couple turns on the screws right there under it that help the midrange fueling. Seems to boost a little faster now, need to mess with the boost compensator. Surprisingly, the bolt I thought I snapped wasn’t totally broken and pulled out just barely holding on to a thread!
D6013678-786C-4717-BC98-A481C2733E64.jpeg
490DE6CA-F78A-4682-8297-A51D697AE2FF.jpeg
 
Joined
Aug 2, 2019
Messages
602
Location
Wilmington, North Carolina
While I had it off I went ahead and gave the injection pump a couple turns on the screws right there under it that help the midrange fueling.
Be careful, note how many full screws you adjusted it by and it's not recommended to mess with fueling much until you have an EGT gauge, easy way to fry your engine. Not to rain on your parade just don't want you frying your engine without knowing haha
 
Joined
Jul 11, 2021
Messages
10
Location
Okinawa, Japan
Be careful, note how many full screws you adjusted it by and it's not recommended to mess with fueling much until you have an EGT gauge, easy way to fry your engine. Not to rain on your parade just don't want you frying your engine without knowing haha
Thanks! Yeah I have EGT, Boost, oil pressure, and coolant temp gauges. Running a Garrett 60-1 wheel in the CT26 housing. Goes well! Midrange is laggy but at 3k rpm it hits real hard up to 3300. Adding some clicks on the compensator should help with that. Right now hitting 18psi.
 
Joined
Dec 7, 2019
Messages
818
Location
North Carolina, USA
Thanks! Yeah I have EGT, Boost, oil pressure, and coolant temp gauges. Running a Garrett 60-1 wheel in the CT26 housing. Goes well! Midrange is laggy but at 3k rpm it hits real hard up to 3300. Adding some clicks on the compensator should help with that. Right now hitting 18psi.
I'm guessing you're military in Oki. Hope you ship the LC home when you PCS back stateside. When I was there a running used engine from typhoon motors on Foster was about $550. Bet money if you buy a spare 13BT and put it in the back of the BJ74 to ship with it you could likely sell it on Mud and recoup any of your cost to get the LC back to the US.
 

Users who are viewing this thread

Top Bottom