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Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 7:24 pm
by skid
righto, about 2 years ago I had an issue with my 80 that may have been diesel bug
blew air back down fuel line and its been right for the last 2 years
last weekend it started playing up again
now it struggles to run and wont even idle on its own
but occasionally it will rev out to 3-4000 rpm
I'm lost
was wondering if anybody had had the diesel bug and what thier symptoms were
normally fill up around wellington at one brand of service station, but last weekend I filled up at BP in Rotorua, so maybe thier diesel is tainted
fuk knows
advice please
Re: Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 7:45 pm
by nstacey
My Hilux had similar symptoms and that was air in the lines. If its diesel bug, remove your filter and have a look...
Re: Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 7:53 pm
by Dace
remove the diesel filter and see if it has slime in it
Re: Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 7:54 pm
by badnuz
http://envirotab.com/we sell these to fleet operators to kill diesel bug in their storage tanks etc, do the job pretty good

Re: Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 9:45 pm
by skid
so far you tell me to remove filter look for slime etc
filter was new when motor was rebuilt, about 8-9 months ago
replaced it today again
old one was clean as a whistle
next answer please
Re: Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 9:52 pm
by red-devil
skid you may have a air leak in the fuel lines somewere.
check around the filter first, have u been playing around the injectors
jono
Re: Diesel Bug Symptoms
Posted: Sat Jul 17, 2010 11:27 pm
by wopass
skid wrote:so far you tell me to remove filter look for slime etc
filter was new when motor was rebuilt, about 8-9 months ago
replaced it today again
old one was clean as a whistle
next answer please
if filter was clean then could still be tank poopoo blocking pick up but yea aggree could be air leak also, pop the fuel line off at the filter and off at the tank and pressurise it with about 10psi and see if theres any leaks in the line.
just guessing
Re: Diesel Bug Symptoms
Posted: Sun Jul 18, 2010 1:24 am
by its_that_guy2
stupid question skid but ... im guessing after you had your swim you drained the tank etc rite ?
another thing you could try ( not sure if it works with diesels ) is a trick i heard was to add a few cap fulls of meths to the tank to rid any water ..... apparently id dissolves or gets rid of moisture and water in tank and lines so ive been told ..
( again tho that was for petrol not diesel cant hurt tho can it ? )
Re: Diesel Bug Symptoms
Posted: Sun Jul 18, 2010 7:51 pm
by koma
Has it got a small gauze filter on the injector pump itself?
Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 7:54 pm
by DieselBoy
its_that_guy2 wrote:stupid question skid but ... im guessing after you had your swim you drained the tank etc rite ?
another thing you could try ( not sure if it works with diesels ) is a trick i heard was to add a few cap fulls of meths to the tank to rid any water ..... apparently id dissolves or gets rid of moisture and water in tank and lines so ive been told ..
( again tho that was for petrol not diesel cant hurt tho can it ? )
Yep, it can hurt. Pre ignition in a diesel is VERY bad, which adding alcohol to the fuel could cause.
The diesel fuel filter has a water trap and a water warning light on it for that reason.
Blow back through the lines again. If that doesn't make a immediate difference for a few mins, then its not the bug. Also the bug will be present in the water trap in the bottom of the fuel filter.
80 series's have a gauze in the inlet to the injector pump, fish that out with the hooked end of a scriber and give it a clean.
My guess is that its electrical, seeing as its been drowned.
So the most likely electrical component that could cause these sort of symptoms would have to be the fuel shut off solenoid. Simple put its a valve on the injector pump controlled by the ignition key that shuts the fuel off to the pump when you turn the key off, and opens up to allow fuel to the pump when the key is turned on.
It might be not opening properly after its dunking

Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 8:27 pm
by Pedro
DieselBoy wrote:its_that_guy2 wrote:stupid question skid but ... im guessing after you had your swim you drained the tank etc rite ?
another thing you could try ( not sure if it works with diesels ) is a trick i heard was to add a few cap fulls of meths to the tank to rid any water ..... apparently id dissolves or gets rid of moisture and water in tank and lines so ive been told ..
( again tho that was for petrol not diesel cant hurt tho can it ? )
Yep, it can hurt. Pre ignition in a diesel is VERY bad, which adding alcohol to the fuel could cause.
The diesel fuel filter has a water trap and a water warning light on it for that reason.
Blow back through the lines again. If that doesn't make a immediate difference for a few mins, then its not the bug. Also the bug will be present in the water trap in the bottom of the fuel filter.
80 series's have a gauze in the inlet to the injector pump, fish that out with the hooked end of a scriber and give it a clean.
My guess is that its electrical, seeing as its been drowned.
So the most likely electrical component that could cause these sort of symptoms would have to be the fuel shut off solenoid. Simple put its a valve on the injector pump controlled by the ignition key that shuts the fuel off to the pump when you turn the key off, and opens up to allow fuel to the pump when the key is turned on.
It might be not opening properly after its dunking

I had a look at it last night, pulled the filter off and it was dead clean, how ever when you pumped the filter it leaked out the bottom of filter, we swappes it back to old filter which also looked clean, and reassembled, when i went to prime the filter again fuel would not come thru, infact when i took the line off the inside of filter there was the hiss of a vacuum, blew down the line no worries, put it back on and it primed easily, started motor and ran up to full revs no problems, then filter pump then sucked down and it stopped again, we then blew back thru the line to tank and reprimed, my guess is the fuel line connection or rubber bits has delaminated inside the hose and is acting like a one way valve, low revs it ok, wind it up and tends to block the hose, going by there no shit in filter i reckon it unlikey anything in tank, and it a hose issue
Pedro
Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 8:48 pm
by DieselBoy
Pedro wrote:DieselBoy wrote:its_that_guy2 wrote:stupid question skid but ... im guessing after you had your swim you drained the tank etc rite ?
another thing you could try ( not sure if it works with diesels ) is a trick i heard was to add a few cap fulls of meths to the tank to rid any water ..... apparently id dissolves or gets rid of moisture and water in tank and lines so ive been told ..
( again tho that was for petrol not diesel cant hurt tho can it ? )
Yep, it can hurt. Pre ignition in a diesel is VERY bad, which adding alcohol to the fuel could cause.
The diesel fuel filter has a water trap and a water warning light on it for that reason.
Blow back through the lines again. If that doesn't make a immediate difference for a few mins, then its not the bug. Also the bug will be present in the water trap in the bottom of the fuel filter.
80 series's have a gauze in the inlet to the injector pump, fish that out with the hooked end of a scriber and give it a clean.
My guess is that its electrical, seeing as its been drowned.
So the most likely electrical component that could cause these sort of symptoms would have to be the fuel shut off solenoid. Simple put its a valve on the injector pump controlled by the ignition key that shuts the fuel off to the pump when you turn the key off, and opens up to allow fuel to the pump when the key is turned on.
It might be not opening properly after its dunking

I had a look at it last night, pulled the filter off and it was dead clean, how ever when you pumped the filter it leaked out the bottom of filter, we swappes it back to old filter which also looked clean, and reassembled, when i went to prime the filter again fuel would not come thru, infact when i took the line off the inside of filter there was the hiss of a vacuum, blew down the line no worries, put it back on and it primed easily, started motor and ran up to full revs no problems, then filter pump then sucked down and it stopped again, we then blew back thru the line to tank and reprimed, my guess is the fuel line connection or rubber bits has delaminated inside the hose and is acting like a one way valve, low revs it ok, wind it up and tends to block the hose, going by there no shit in filter i reckon it unlikey anything in tank, and it a hose issue
Pedro
Yeah, could be, but thats very unusual if it is, make sure you post up the outcome!!!!
Have you checked the tank breather?? That is a one way valve system from memory.
Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 8:54 pm
by Fakey
That would be my next idea, Take the fuel cap off an try it if the breather is blocked it should run better without the cap on:D
Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 10:10 pm
by skid
Fakey wrote:That would be my next idea, Take the fuel cap off an try it if the breather is blocked it should run better without the cap on:D
have run it with cap loose and cap off and it made no difference
[quote="DieselBoy
My guess is that its electrical, seeing as its been drowned.
[/quote]
this problem also happened 2 years ago long before I decided to become a submariner
hope to get to it tomorrow to check fuel lines/breathers and then drain tank and pull inspection panel for closer look inside tank

Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 10:23 pm
by wopass
run it up to when it sucks the primer down and stalls then get under and pull the fuel supply line off the tank, this will tell you if its blocked in the line or in the tank.
wheres mike, this is the 3rd time ive tried to post this and everytime i click submit it boots me to a different page and drops the post... Grrr!!!
Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 10:46 pm
by red-devil
mite sound silly but could the fuel line be to soft so when the pump is suckin hard out at full revs the hose closes up.
Re: Diesel Bug Symptoms
Posted: Mon Jul 19, 2010 10:49 pm
by Fakey
Try getting a container full of fuel an run a line directly into the line into the fuel filter to eliminate the trucks fuel lines, If it runs ok work your way back to the next join between the steel line an hose an connect it in there
This will help ya locate any blockages in the lines if there are any an its easier than draining the tank, if it still runs ok right up to the lines running out of the tank then youll have to drain it anyway but atleast youll know the lines are clear

Re: Diesel Bug Symptoms
Posted: Tue Jul 20, 2010 6:54 am
by pressy
hi there, a funnny man on here had the same problem, i found his tank had shit in it and was blocking the fuel pick up in the tank. i would suggest the same for you.
Re: Diesel Bug Symptoms
Posted: Tue Jul 20, 2010 7:46 am
by tallsam66
Sometimes if there is a fuel blockage in either the tank or the line the pump on top of the fuel filter will get sucked down as the pump tries to suck fuel.
Re: Diesel Bug Symptoms
Posted: Tue Jul 20, 2010 3:23 pm
by terranoman
I had the same problem so what i did was drained the fuel tank fulled it up with boiling hot water with acid detergent for cow shed vat then drained that bllew out the lines and then brought diesel bug killer off 'power up' for $25 filled the tank up with diesel and about 100mm of the killer ran for 15mins then drained fuel tank and refilled. New fuel filter and removed gauze in main line into injecter pump. this stuff is like tar/jelly
Hope this helps
Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 8:00 am
by SV1K
Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 8:38 am
by skid
this arvo/evening, gonna go deep
drained the fulla yesterday into 8 buckets and a quarter of a jerry can and 2 ice cream containers

Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 9:29 am
by badnuz
skid wrote:a quarter of a jerry
in 2 ice cream containers

HAHA!
Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 9:32 am
by wopass
skid wrote:this arvo/evening, gonna go deep in jerry and 2 ice cream containers

Ewwww
Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 10:36 am
by suzolla
Before you drop the tank, presume that is why you drained it, why don't you take out the pick up and gauge float out first, it is bolted to the top of the tank and accessed thru a cover plate under LH rear passenger seat. Then you can check the pickup filter.
Cheers
Tim
Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 12:46 pm
by SV1K
Re: Diesel Bug Symptoms
Posted: Wed Jul 21, 2010 9:21 pm
by skid
fuk this shite just gets weirder by the minute
drained it yesterday, went back this evening and removed inspection cover, cleaned around top of tank and checked all fittings etc
then removed top cover and pulled out the pick up and float etc etc
so tank was spotless
pick up filter was lying in there, but it wouldn't affect anything, coz it would float
so pulled lines off and blew them all out and went to get new ones, but my mechanic who shall remain nameless insisted they were only 3/8 when I kept saying they were bigger, so we ended up with too small fuel lines and a shut shop
so re-installed all old stuff and revved it up
no problems
went for a short drive, no problems
so put everything back together and filled it up and added diesel injector cleaner
will go back tomorrow and take it for a longer drive to see how she goes
then replace lines in future
and after that
fuk knows, wait n see I suppose
Re: Diesel Bug Symptoms
Posted: Thu Jul 22, 2010 7:48 am
by Pedro
skid wrote:so pulled lines off and blew them all out and went to get new ones, but my mechanic who shall remain nameless insisted they were only 3/8 when I kept saying they were bigger, so we ended up with too small fuel lines and a shut shop
that be the same nameless mechanic that left the bung out of the tank and they wondered what the splashing sound was as he refilled the tank?? Never seen him move so fast
Pedro
Re: Diesel Bug Symptoms
Posted: Thu Jul 22, 2010 9:58 am
by kbushnz
This is a long shot, but it has happened to me.
Check the gas cap.
They have a vent / valve in them, it could be blocked.
I had a new (secondhand) car and it would cough and splutter occasionaly.
Checked everything and all was good. Would idle and start fine but after about 10mins of driving would start to show signs trouble.
Turned out the tank was not venting thru cap. Just one big air lock.
Calvin
Re: Diesel Bug Symptoms
Posted: Thu Jul 22, 2010 11:21 am
by tweake
diesels often have a breather pipe off the tank rather than breath through the cap. the breather pipe has a valve on it that can get crap in it and block up.