3b rough starting issue. (1 Viewer)

[Canadianmarty]

ok after doing some research and some testing I think my problem is unique enough to warrant a new post. since last summer my bj60 12v 3b has been starting really rough. takes a couple times letting the glow plugs warm up for a good 10 seconds or more and a couple tries of turning it over for 5-10 seconds before it starts to even sputter. i would need to keep my foot to the floor and sometimes keep the starter turning to assist it for a few more seconds before it will take and not stall. you could literally hear it waking up one cylinder at a time. keep in mind this was happening equally in +15 or -10 celsius. always tons and tons of smoke (white-ish), fills up the yard. lots of black soot left in the snow behind the pipe. but it always started eventually and ran like a top once it warmed up. about a year ago, a good 6 months before all this started i did the following work;

cleaned the fuel tank and sediment filter
all new soft fuel lines
cleaned out all the hard lines
new fuel filter
new glow plugs 10.5v
had the injectors hydrosonic cleaned
new pre combustion cups
valves lapped
new headgasket
head was retorked after a couple heat cycles

recently new bosch primer pump (i can always push it forever and it never gets hard. is this right? it pushes fuel to the bleeder on the filter.

more recently, a couple weeks ago I did a little more investigating and found two of the plugs burnt out so i replaced them and it started right up! i thought great, problem solved, so stupid that i left it for so long. however, I maybe got one or two easy starts before it went back to really rough, smokey and difficult. so tonight i went out, pulled the glow plugs, they tested good, so i tested them off the bracket they normally connect to and although they light up slower than off the battery, they do get hot (took about 10 second instead of 3)
I also noticed a couple spots around the injectors that appeared slightly wet or rather just darker than dry. so I tried tightening all the connections above and the injectors themselves but they were all tight. I put it all back together and now it won't start at all, it just turns and turns, no sputters or anything. I want to double check my bus bar connections tomorrow with the volt meter, maybe something didn't reconnect properly there tonight. but if i find that i still think i will have a rough start issue
i seem to have a working time delay glow system, I gotta check voltage but it seems to supply nearly full voltage for 20 seconds or so and then shuts off completely. dash light is only on for 3 seconds though. there is no longer low voltage period so I don't think i have a super glow system (at least not a working one)

my gut says its an air getting into the fuel issue. could it be my injectors are sucking in air? or maybe the seat that goes down their hole isn't sealing it to the head properly? if air is getting in lets say around the sediment filter, would it migrate to the injectors to cause difficult starts until it is purged? i feel like in that scenario it should sit in the fuel lines until it reaches the injectors and then cause issues.

 

[OTBT]

Sounds like air in the lines to me, too. Try removing the glow plugs (to prevent compression) and cracking open each fuel line in turn (at the injector) and cranking until no bubbles appear. Another thought that occurs to me is that the 'O' ring on the bleeder at the fuel filter may be loose and letting air in ?

I hope this helps ...

 

[AirheadNut]

I am leaning to air contaminating the fuel lines as well. I have never heard of injectors sucking in air (or anywhere past the injector pump) but I suppose it may be possible. When you cleaned the injectors were they disassembled at all? Any chance of contamination in the nozzle between the pintle and nozzle body that could damage the nozzle seat? Have you performed a compression test? Checked injection timing? Completely different engine, but on one of my VW TDI's the injection timing was way off when I got it and caused very similar symptoms (car wouldn't start cold unless the glow system was tricked into glowing for the full length of time, even in summertime temperatures). May be worth pop testing your injectors to see what the pressure balance and spray pattern is like.

Hopefully something here helps, I really don't know what could be causing the issue, just throwing some ideas out there.

One other thing to consider, it may be worth investigating any possible causes for the two glow plugs to have burnt out so quickly.

 

[Canadianmarty]

Yeah I think the two glow plugs that burnt out may have been different than the other two, they might have been 6v. I can’t remember changing any but possibly the other two burnt out months earlier and I replaced them with 10.5. I really can’t remember why I had two different plugs in there.

Does anyone know how to test for air infiltration between the primer pump and injectors?

Injectors were completely disassembled when they were cleaned by a mechanic, they should be good.

Injector timing is a good idea to check. I’ll look into how to do that.

 

[OTBT]

The injector timing is pretty simple, but a bit of a PITA because of the location of the nuts/bolts - simply rotate the injection pump in one direction or another (starting at where the alignment marks on the pump & timing cover align). If your engine is 24v you may wish to use high voltage glow plugs ...

 

[Cruising Canuck]

I've got the exact same issues as you do. I have not been able to solve it. My next step was to do a compression test. Just haven't gotten around to it.
I'll be watching this thread. I've been very hard on my starting motor for the last 5 years haha

 

[Canadianmarty]

I've got the exact same issues as you do. I have not been able to solve it. My next step was to do a compression test. Just haven't gotten around to it.
I'll be watching this thread. I've been very hard on my starting motor for the last 5 years haha

My thought is injectors. My mechanic said they were not in the best shape. I’ve been waiting on wife approval to do a turbo set up and I’ll replace them then. Until then I’ll search for air leaks and maybe do a Wilson switch.

The fact that it didn’t start last night bothers me because it has always started eventually, just always rough and Smokey

 

[Cruising Canuck]

I've got some "rebuilt" injectors sitting on a spare engine. I was going to pull them this winter and install them in my truck to see if that solves anything.
The other thing I was going to try this winter is replace the fuel pump diaphragm. But apparently when that thing is faulty it results in a fast idle.

 

[grayjs]

I would definitely try the wilson switch. Remember you need to swap the glow plugs also.

 

[Canadianmarty]

I would definitely try the wilson switch. Remember you need to swap the glow plugs also.

10.5v correct?

 

[grayjs]

yes correct NGK Y-147T

 

[-MaTTi-]

recently new bosch primer pump (i can always push it forever and it never gets hard. is this right?

No it’s not. That means you get air to the line while pumping. Check also the mesh filter under the banjo bolt at the pump body that the fuel income is not blocked.

My 3B starts quite easily without glowing at 0°C.

 

[lacalvette]

keep in mind that fuel system is under vacuum before the feed pump (including injector’s return and hand priming pump)
So fuel tank, hard and soft Line, water separator… will let air « in » if there is a leak.

Anything after the feed pump is under pressure and there is a check valve built in the feed pump unit to keep it pressurized.

So if there is a leak at the main filter, IP, injection hard line or injector, that will be « diesel out »

(the hand priming pump should come hard after a couple cycle)

This mechanical injection engine can’t really get rids of the air by it self, once air reach injectors, you need to remove it. It would have a rough idle at all time, loss power.

If your truck is a Canadian market, I think it should have the super glow system. You could try a manual set-up for a couple of cold start up? Maybe a bad relay?

Is the coolant level is steady, no slow internal leak?

You may also check for the compression, bad one could lead to rough start ( air not enough hot )

 

[Canadianmarty]

Ok update: after checking glow plugs the other day (all 10.5, tested ok) I must have put the bus bar back on them poorly somehow, I was getting voltage at the little L shaped arm that connects to glow #4, but not down the rest of the line. Took it apart last night, sanded all connections and put it back together. Glowed it a few times while testing with the volt meter and it fired right up, smooth without extra smoke. Later startups worked just as well.
In my testing with the volt meter however, I learned I have a working super glow system. The plugs get 8-9v for about 3 seconds and then 4v for another 20s or so. This is why they should have 6v plugs, so that they fire hot really fast at 8v and then run at 75% for a while keeping the engine idling while warming up. This is obviously not optimal with 10.5v plugs as they won’t get as hot.
I remember installing all 6v plugs a couple years ago and they’ve all failed at some point along the way to now. Maybe the initial 8-9v is just too much. So I will be installing a Wilson switch to have more control and to keep the 10.5 plugs as they’re easier to find.


So just a last question about the bosh primer pump. It doesn’t ever screw down which seems right. But it doesn’t ever get hard to push, however it does push fuel out the filter bleeder. Truck is running great now so I don’t think air is the problem

 

[roalco]

If your superglow is working, keep it! Its a great system. Bosch GPT-214 (6V, .3ohm) glow plugs are what you should be using, they are high quality and last. they are readily availiable from ebay in australia (ie. BOSCH GLOW PLUG X6 6.0V FOR TOYOTA LANDCRUISER HJ47 HJ75 2H 4.0L | eBay - https://www.ebay.com/itm/BOSCH-GLOW-PLUG-X6-6-0V-FOR-TOYOTA-LANDCRUISER-HJ47-HJ75-2H-4-0L-/301880969111?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=705-154756-20017-0) years ago i bought two sets of 6 (makes for three sets of 4 for my engine, one installed, one spare set in the truck and one at home) and am still running the first set!

 

[Canadianmarty]

If your superglow is working, keep it! Its a great system. Bosch GPT-214 (6V, .3ohm) glow plugs are what you should be using, they are high quality and last. they are readily availiable from ebay in australia (ie. BOSCH GLOW PLUG X6 6.0V FOR TOYOTA LANDCRUISER HJ47 HJ75 2H 4.0L | eBay - https://www.ebay.com/itm/BOSCH-GLOW-PLUG-X6-6-0V-FOR-TOYOTA-LANDCRUISER-HJ47-HJ75-2H-4-0L-/301880969111?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=705-154756-20017-0) years ago i bought two sets of 6 (makes for three sets of 4 for my engine, one installed, one spare set in the truck and one at home) and am still running the first set!

But I did run a set of 6v and they all burnt out in less than 2 years.

 

[roalco]

What brand? My first set of glow plugs (which was from new) lasted over 12 years as a daily driver, subsequent sets have lasted at least 10 years per set. Don't forget to ALWAYS replace ALL of the plugs together, even if only one fails. If you don’t, then the resistance imbalance will certainly cause system problems.

 

[roscoFJ73]

had the injectors hydrosonic cleaned

This is unusual for a diesel. Its something you do for petrol injectors. Diesels use replacement nozzles as the parts are considered unserviceable (unlike the more ancient diesels). Diesel injectors also need to be adjusted for cracking pressure etc.

So just a last question about the bosh primer pump. It doesn’t ever screw down which seems right. But it doesn’t ever get hard to push

It should screw down into its locked position. They are not supposed to go hard. They only have a tiny rubber o ring and if its pushing out fuel, its doing its job.

 

[Canadianmarty]

This is unusual for a diesel. Its something you do for petrol injectors. Diesels use replacement nozzles as the parts are considered unserviceable (unlike the more ancient diesels). Diesel injectors also need to be adjusted for cracking pressure etc.


It should screw down into its locked position. They are not supposed to go hard. They only have a tiny rubber o ring and if its pushing out fuel, its doing its job.

I was told the newer bosch replacements specifically don’t screw down.

I’ll have to look into injectors soon, I wonder how much improvement that would make

 

[roalco]

Yes, the 3B injectors have a softer nozzle and a harder valve needle so that as they wear they stay sealed when closed. After many, many km the needle just moves down slightly and subsequently the cracking pressure falls slightly.
Ultrasonic cleaning is just one minor prep step in rebuilding diesel injectors, as RoscoFJ73 says, and as the replacement nozzles are relatively cheap, and almost always just replaced.
Be very thankful you have these injectors, they are easily rebuilt and calibrated at any proper diesel shop, and for a very good price!