BJ74 just died on highway (1 Viewer)

[bvissers]

My BJ 74 with ~ 320 K KM was driving perfectly normal and the engine simply quit. I managed to glide her in a parking lot and was later towed home. I cant seem to find the cause.

The Issue: when I crank engine it momentarily starts and dies intermediately , the longer its been idle, the longer it seems to run , ie after an overnight sit, it will start and run ~ 15 sec subsequent attempt 3 sec or so. after that will only crank with no fire.

1) I have a full tank of fuel,
2) I have verified that hand primer pump pumps fuel out of filter bleed screw, ( no air was present ) also cracked the exit of fuel filter and fuel passes so IP is not fuel starved.
3) did same test cranking engine with same result, so IP Feed pump is working
4) no visible fuel leaks at hand pump or IP.

This issue has me stumped as for the almost 10 years I own this BJ I have never had an issue remotely similar to this. I am beginning to suspect the IP has had some sort of catastrophic failure ?, but then why would it even run for a few seconds?

Anyone ever experienced similar issue ? any help would be greatly appreciated.

 

[CRZR45]

Try simple first. Check fuel filters for water? I would remove and dump in a container to look for water. Did you crack injection lines to see if fuel making it there? My 2c

 

[bvissers]

My BJ 74 with ~ 320 K KM was driving perfectly normal and the engine simply quit. I managed to glide her in a parking lot and was later towed home. I cant seem to find the cause.

The Issue: when I crank engine it momentarily starts and dies intermediately , the longer its been idle, the longer it seems to run , ie after an overnight sit, it will start and run ~ 15 sec subsequent attempt 3 sec or so. after that will only crank with no fire.

1) I have a full tank of fuel,
2) I have verified that hand primer pump pumps fuel out of filter bleed screw, ( no air was present ) also cracked the exit of fuel filter and fuel passes so IP is not fuel starved.
3) did same test cranking engine with same result, so IP Feed pump is working
4) no visible fuel leaks at hand pump or IP.

This issue has me stumped as for the almost 10 years I own this BJ I have never had an issue remotely similar to this. I am beginning to suspect the IP has had some sort of catastrophic failure ?, but then why would it even run for a few seconds?

Anyone ever experienced similar issue ? any help would be greatly appreciated.

So I jumped the gun on going to forum on this, but will be good to share with others. the issue is minor and relates to the butterfly shut off valve in the intake . I pondered the fact that the longer engine was idle , the longer the engine would run when started. and realized that vacuum bleeds off these trucks with time. I began to suspect that vacuum was always being applied so I disconnected the vacuum line to the vacuum modulator , engine starts and runs just fine, but needs to be shut down manually. I suspect the 24 VDC to vacuum switch is missing or the vacuum switch it self has packed it in. At least I know where to find the problem and although requiring a manual shut down, can use the trusty BJ 74, Had I hald more light when she died, ( and not jumped to worst case scenario) and a second set of hands I may have seen the cutoff modulator being pulled in when I was at side of road stranded, but.... I am still happy with the result. I hope this helps some other BJ 0wner down the road.

 

[bvissers]

Try simple first. Check fuel filters for water? I would remove and dump in a container to look for water. Did you crack injection lines to see if fuel making it there? My 2c

Thank you CRZR45 for those suggestions, yes I had checked the fuel for water, Had not cracked Injector lines yet as I said it runs at times for up to 15 Seconds, ( slow to build up vacuum LOL ) thanks for the 2C all advice on here is always welcome.

 

[Behemoth60]

So I jumped the gun on going to forum on this..... I began to suspect that vacuum was always being applied so I disconnected the vacuum line to the vacuum modulator , engine starts and runs just fine, but needs to be shut down manually.

I was about to reply with this very suggestion. This is a weird problem uniquely related to the 13B-T motor. Faulty vacuum or shut-down solenoids have bested even seasoned diesel mechanics! If you don't know about this... you just don't know!

here's another weird one for the 13BT. If your air filter is dirty, the 13B-T will also shut down your engine under very high Revs/power. Very frustrating when trying to merge onto the freeway. This same VSV/Vacuum/Butterfly shut-down module tries to protect the engine from hydro locking by monitoring for sudden low pressure in the air box (caused by intake going under water, but also by dirty air filter causing enough pressure differential under high load!!!) @loewenbrau spent a long time trying to diagnose that problem.

 

[MyCruiserisaHogBeast]

So I jumped the gun on going to forum on this, but will be good to share with others. the issue is minor and relates to the butterfly shut off valve in the intake . I pondered the fact that the longer engine was idle , the longer the engine would run when started. and realized that vacuum bleeds off these trucks with time. I began to suspect that vacuum was always being applied so I disconnected the vacuum line to the vacuum modulator , engine starts and runs just fine, but needs to be shut down manually. I suspect the 24 VDC to vacuum switch is missing or the vacuum switch it self has packed it in. At least I know where to find the problem and although requiring a manual shut down, can use the trusty BJ 74, Had I hald more light when she died, ( and not jumped to worst case scenario) and a second set of hands I may have seen the cutoff modulator being pulled in when I was at side of road stranded, but.... I am still happy with the result. I hope this helps some other BJ 0wner down the road.

I've had a couple of diesels and the concept of the vacuum system and the shut off valve alluded me when I had a bad clutch master and booster seal which caused me to suddenly not be able to shut down the truck. It happened about a month after I bought it.

I appreciate all of these safety mechanisms, but they can sure catch you by surprise!

 

[bvissers]

Yes its an interesting system for sure, I did not know about the air filter business, very good to know. ( I saw the tubing and thought that was to pressure diff switch of some sort to illuminate a lamp if the filter is dirty) In anycace,, I cheated a little and simply wired in another VSV valve right at the butterfly. The original VSV valve and associated tubing are behind the engine , squeezed in between engine and fire wall, I have scrapped up my arms every time I work there and create a new language while at it. I wired new VSV to an ignition circuit and simply cuts the vacuum when engaged. I am up and running and happy lol. Thanks again for all the helpfully info all.

 

[jblueridge]

Exact same thing happened to me after 1 month of ownership.
It was that shutoff valve.
I have since spent some time half-memorizing the vacuum line routes and functions, just in case.

 

[Hulsty]

here's another weird one for the 13BT. If your air filter is dirty, the 13B-T will also shut down your engine under very high Revs/power. Very frustrating when trying to merge onto the freeway. This same VSV/Vacuum/Butterfly shut-down module tries to protect the engine from hydro locking by monitoring for sudden low pressure in the air box (caused by intake going under water, but also by dirty air filter causing enough pressure differential under high load!!!) @loewenbrau spent a long time trying to diagnose that problem.

I have had that happen a couple of times running high boost with a less than perfect filter. Another trap, happened to me twice is running backwards! I didnt think it possible on a 13BT, but it happens!

 

[SeanBJ74]

Can anybody provide me a pic of where the shutoff valve is. I’m currently have the same trouble with my BJ74

 

[jblueridge]

Left side of engine. Near firewall but you have to reach down fairly far. It has 2 vac hoses and an electrical connector. The main starter wire runs down that way too.

 

[SeanBJ74]

Anybody have a pic of the injector pump.?

 

[FJBen]

Anybody have a pic of the injector pump.?

Red circle injector pump

Green arrow the vacuum valve. It’s tucked under there and a pain to get to.

This green circle is your shutoff butterfly. When you shut the key off, vacuum is applied and closes the butterfly valve choking off all the air to the engine.
Unhook the vacuum line and it will stay open. If it still dies after starting, then this isn’t your problem.

 

[sodafeld1]

That is interesting. I was wondering what the shut off butterfly was from a cooked pre84 2h I have. The post 85 2h engines I have, don't have it. Not sure if I want it either after reading what it does for you!

My 2h has the edic, but I kind of like how my old b engine had a pull to stop cable, older tractors too. Might do that for the 2h I am building.

 

[sodafeld1]

That is interesting. I was wondering what the shut off butterfly was from a cooked pre84 2h I have. The post 85 2h engines I have, don't have it. Not sure if I want it either after reading what it does for you!

My 2h has the edic, but I kind of like how my old b engine had a pull to stop cable, older tractors too. Might do that for the 2h I am building.

13bt is meant to be a v good engine though!