13bt slight hesitation

[Oldtoy74]

My Oldtoy has slight hesitation on acceleration, mainly around 1300-1800rpms, more noticeable when I manually throttle from engine itself and keep revs at that range, if I rev or juice up past that point no issue? The funny thing is when tank is low it the 13bt considerably runs smoother, and when tank is full the hesitation is noticeable and doesn't seem to run as well compared to low tank.
I been reading up past posts on hesitation but still a little green, so I intend to start with basics
1, replacing vacuums lines
2, replace fuel lines/ or check for air leakage
3, drop tank and check for muck at pick up

Other points that pricked my attention was something crusher has mentioned regarding a ripped diaphragm, ?.? Not sure where??
When starting I need to give a little pedal support to get some juice in prior to starting and manually twist throttle up to keep revs at about 800rpms, if not it's like a cage fight in my engine bay when sitting overnight, (15 degrees amb.).......when engine warm still has little minor hissy fit prior to Idle without any pedal support, .....with-pedal support fires up great and lands at idle. If any other mudders have had hesitation with 13bt, your feedback, solutions are most welcome.
Ch ch ch cheers

 

[dabasscow]

G'day oldtoy74

Having a few issues myself at the moment, with rough idle at start up. When I get some spare time I will be pulling my injectors getting them checked, once warm mine usually runs OK. but the other day I filled up and was running rough again after I filled up the tank. Was a bit strange. I think I may have a leaking injector.

Up here in Rocky there is a problem with a mould growing in diesel tanks (at the servo), it blocks up the fuel filter. My old mans Patrol blocked the filter in a matter of weeks, had to use a type of fuel conditioner to sort it out as well as replace the filters again.


Try posting this in the Diesel section, you may get more replies

 

[toms42]

I have exactly the same issue get in crank hand throttle a turn hit key runs at high idle, once warm back it off to 800rpm and it runs sweet been doing it for years. will be interested to hear opinions thinking it is diaphragm in governor.

 

[yotahed]

13BT doesnt have a governor diapragm. that would be a 3B
13BT has a diaphram in the boost aneroid/torque control module.

Depending on the the mileage of the pump, your plungers could be slightly worn or the barrels leaking.
I've had several inline pumps on the bench that deliver balls out crazy fuel at full load and the idle delivery is acceptable, but when you check the cranking delivery, there is next to no fuel.
A common workaround is, like you say, give it a bit of pedal prior to turning the key and it'll get you going.

Also check your glow screen to see if it's working correctly as it will cause a similar symptom, but with white smoke.
If you get next to no smoke and it starts like s***, i'd say the starting fuel delivery is way low--->worn or leaking(o-rings) plungers/barrels.

You usually tell if a pump is worn by the low rpm delivery.

On the hesitation, your torque control (boost compensator) settings could be messed up or you have a leaky seal or torn aneroid diaphram.

 

[John Galt]

a problem with a mould growing in diesel tanks

mould or any other microbe needs water to live. So how is water getting in the tank? Condensation? wet fuel?

On my 13B-T I installed one of these filters after the sedimenter to catch any crud in the fuel before the lift pump and filter. I run biodiesel/VO blends and it lets me see the condition of the fuel mix when it's cold.



They're a MBenz filter.

NAPA 3972 here in N.A.

 

[dabasscow]

Hi John,

 

[dabasscow]

The water is in the tank at the fuel station, due to several possible a leaking under ground tank, flooding, poor tank maintance, the high humidiity here also leads to consedentation, it is recomended around here to use the more popular fuel stations that have higher fuel turn around to ensure you are supplied good Diesel.

 

[dabasscow]

Hi Yotahead,
With the glow screen, when you say no working corrctly, do you mean it's not turning on to pre heat? OR staying on?

Here in OZ in QLD it is rare for it to get below 15 degrees C

What are the other issues caused by a torn Diaphram? Can this cause to much fuel when boosting?

Mine blows a lot of smoke, whitey grey in the morning on start up and the usually black smoke on acceleration.

 

[yotahed]

Hmm. Could possibly be low cracking pressure at the injectors. Will give it a slightly advanced timing condition, as its dumping too much fuel too early. But that's something you'd need tested.

You can try removing the injector pipes at the injectors and put little cups under each open end to catch the fuel. have someone crank it over for 12 seconds and see if the volumes are equal across all 4. If you have next to no fuel, then that's the issue. You should get at least 2mL(cc) for 12seconds. It'll be more if the pump is good since theres no restriction from the injector. If you get less or none on 1 or more cyl, or one is way lower than the others, that's your issue. Easy check for peice of mind

The glow screen should give a smooth start if its working right. If its warm out, like you say, it obviously won't come on for as long. You could try jumpering it to the battery while somebody starts it and see if it makes a difference. Sometimes the timers are pooched. Not sure what that particular one uses to sense the temps and how long to glow. Check your manual on that one..

A ripped diaphragm in the boost aneroid would cause a lack of power, because the aneroid limits your fuel delivery until you reach a set boost pressure. You can check it. 4 screws on the plate where the boost line hooks to and its right under it.

 

[dabasscow]

Thanks Yotahed,
I will check soon, when I do a service in the coming weeks.
Sorry Oldtoy74 for hijacking your thread.

 

[Oldtoy74]

all good dabasscow, the questions you posted were similar to what I had in mind, esp around the glow screen,
What yotahed has mentioned regarding the cranking & pump that has no fuel prior to starting due to leaks in barrel / plunger / leaking orings , has made me think I'm outta my depth on this subject, I need to do a lot more reading to understand what's what, as injector pumps are way too complicated for me to start playing with. If yotahed could confirm whether to get this plunger barrel orings checked from a professional, would this be an expensive visit, and if confirmed is it a big job to repair,

 

[dabasscow]

Hi Oldtoy74,
INjection is a bit of a hard one to do your self, I'm going to get my injectors checked 1st local diesel guy said he would test them for free for me if I pull them out. Then go from there with the rest.
Down your way everyomne I know speaks highly of Mike Vine Turbochargers for a reliable diesel tune and diagnosis. In Capalaba