air sucking into fuel system (1 Viewer)

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Jan 11, 2009
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Location
Eastern Ontario Canada
greetings i will start by saying mr.moto posted a real time help for this earlier .

1984 lc 3b engine th55 trans 3/4 of the way through my first tank ! and yes i am new to the diesel world and i am requesting some clear and concise help and understanding that i am new to this.

recently i used a bottle of lucas injector cleaner at 1/2 a tank ,soon after i was experiencing power loss and hesitation . I changed my fuel filter (then primed bled and primed ) still stalling, soon after i changed my priming pump ,still priming ,drove aprox 5km then stalled on the way home in traffic (1/4 tank on the gauge )mr.moto sugested maybe the pickup is sucking air ??or some where else in the system there is a leak and thus air is being sucked into the fuel system .
injector lines have been cracked and spurt fuel ,once again the sugestion was made add fuel ? so after 20l in a jerry can (tank reads 1\2now ) and 53 L @ the pump (tank now full on gauge ).priming pump does not leak after thread sealand applied to the threads and vehicle idles just fine without stalling but still lacks the power it had before all of this .
i would appreciate your candid and constructive help
is it as easy as 1/4 tank on gauge is in reality Empty ??

i am hesitant to drive it to work but it is my DD i need ideas and solutions , i can not get left in traffic on the side of the road again twice is already too much !

thanks goes out to mr.moto for his tugem out of rushhour traffic and all the time put in to get me (and keep me )going it does not go unnoticed !
moosecruiser
 
Aw, come on folks - someone must have a thought or two... It's boggling my mind as to what is going on here...

There is definately AIR in the fuel system. When the engine starts to stall, pumping the primer brings the power back (though it's impossible to do this while driving)

With the addition of fuel (~80L) the stalling problem seems to have gone away - though it had gone away before as well.

With the tank capacity being 90L, is it possible that the ~10L left in the tank was below the pick up level? Where is the fuel tank pick up on these tanks? is there an internal sump?

If the primer is able to bring fuel back, and prevent a stall is it realistic to say that the air leak is before the primer, or after it? I have not driven it with the "lack of power" but could it just be that the fuel being sucked up is somewhat of a foam, so has lots of air in it, and thus, not as much fuel is getting to the injectors?

It does seem a bit odd to me that the gauge would read 1/4 when there is only 10L left, I know when mine reads empty I can only fit 70L in.

The engine does not seem to run rough now (at least when it does, the primer solves the problem) so it does not seem to me like a chunk of sludge could be blocking an injector, but could it be blocking the line enough to restrict the flow, enough to cause a power loss? What is the best way to check the lines for a blockage? (is it easier just to replace them with hose from the sedimenter to the fuel tank, and the sedimenter to the fuel pump?

Looking for a solution!! we need to get this thing back to reliable for moosecruiser.... I don't want to use my Tugum around town unless it's on a Heep!! (towing cruisers on trails is OK)

Thanks!
 
Is this a relatively new issue, as in could this be a bad tank of fuel?

Personally, my sending unit is bent (and has been for years) so my BJ60 will run out of fuel when my fuel gauge reaches just under half a tank, therefore I need to keep it topped up, which is good for a diesel anyway.

Is there any smoke you should tell us about? If so what colour is it?

We'll start with these questions.
 
so
why did you used the inector cleaner? fluke or reason for doing so?
did you just dump the bottle in the tank or did you remove the fuel filter and fill the filter and reinstall?
when was the last time you filled up before the injector cleaner was installed?
how many km on the truck/engine?
is this an ontario truck or imported from another province?
 
Good questions Crushers. I'm sorry if I missed it, but is this a BJ60? I have come across what seems to be a similar problem with my truck and also with a friend's truck. The portion of the fuel pickup tube on the outside of the tank rusts through allowing air into the system. Toyota sells a new pickup tube for ~$50 and you'll probably want new screws while you're at it (I had to get a little "creative" while removing mine). On both trucks there was a visible damp/stained spot on the right front corner of the fuel tank. Perhaps try putting a clear tube in line @the injection pump to see if you can see any bubbles? Hope this helps
DSLCRUZR
 
Perhaps look into why you needed to use thread sealant on the primer pump when the crush washer should be all that's needed to do the sealing there?

(I'd prefer to re-use the original crush washer if the one supplied with the new pump had been unsatisfactory. ---- Rather than go to using sealant.)

Perhaps that primer (or the way it was fitted) is now somehow interferring with the operation of your fuel pump because both the "primer pump" and the "fuel pump" rely on the SAME non-return/check valves. (And the primer pump sits right on top of one of them.)

Just an idea. (Perhaps "sealant" penetrated further than you intended, perhaps you dropped dirt/debris inside, perhaps the primer pump isn't designed to accomodate the spring and stem that it sits on top of, or perhaps......................Well - You get the idea!)

:cheers:

(I'm thinking that if your new primer - or the way it was fitted - is somehow interfering with the operation of the check valves - then your injector pump would be probably being starved of fuel as a result.)

But I've no idea why some power loss and hesitation apparently occurred before you even touched the primer. (So I could well be on the wrong track here.)
 
could be a faulty primer but then he said it was happening before the primer install...no?
 
Thanks for all the replies thus far... I'll do my best to fill things in...

ROM;
Yes, this is a new issue - the whole truck is "new" this is the first tank of diesel run through it. It only started happening when the tank reached 1/4

No smoke, white or black. When it's running it runs great, but we can tell there is definately air in the fuel.

baxter650;
Hope the lift pump is not going south!! is there an easy place to put a vacuum gauge?

crushers;

Injector cleaner was put in just as a preventative measure - to clean anything out that was in there... (maybe we shouldn't have!)

Fuel filter was changed after injector cleaner was run through - problem stayed..

This was the last tank to go in, and the only tank to go in - about a week ago was fill up - has been runnign fine untill 1/4 tank.

341K km on the truck

Dont know the entire history of the truck, I heard that it was in Tuktuyuktuk for a while... but it has been in ontario for quite a while.

dslcruzr;
Yes this is a BJ60 - 3B engine. Will check the pickup tube...

lostmarbles;
The thread sealant was a temporary fix to the washer problem, it did seal the primer pump - but the problem still persisted ... And the problem was the same before we changed the primer pump so I don't think it was related to the sealant...


So, the developments in the last 12hrs.... We filled the tank completely, and the hesitations appear to be going away, as well as the power loss. My theory now is that we were sucking foam/fuel from the tank, or at least some airated fuel... Truck seemed to get better slowly after the fuel up - and ran OK this morning. So.... this may all come down to the sender, or pick up... (we hope anyway!!!)

Thanks for all the help - and any further thoughts are welcomed as this might not be the end of it!!
 
suggestion,
when the tank gets down to 1/4 drain the sludge out of the bottom, filter and refill.
after that don't let the tank get down to 1/4 again.
sounds like poor fuel at first and now the poor fuel is diluted enough to run fine.
maybe look at another fuel filter (keep the old one for now) just to make sure any imputities have been caught by the first filter change.

good luck
 
hey guys it appears to be running fine 20 km today and not even a hesitation . will keep you posted we are putting in a block heater this weekend (un related )and i am putting tow hooks on as well (maybe related )thanks for the input, i guess for now i will consider 1/4 tank dead empty ! in my mind or just not let it go below half .
 
I think your gauge is fine. In a truck with that many miles, it is highly likely that you have a ton of crap in your tank. That combined with fuel cleaner and some bad fuel probably caused your issue. I had the same issue with an 86 FJ60 that had a ton of varnish that washed through the system. Once it found its way to the filter or combustion chamber, it ran much better. If you have time clean out the tank, run another can of cleaner and then change the filter. Also, change the primer. Bosch makes an inexpensive replacemnet. If you had air coming in, you'd be getting white smoke at startup.
 
If you had air coming in, you'd be getting white smoke at startup.

Funny you say that.....

The brand new primer pump we put on is a bosch. I purchased a new one for his truck and a new one for mine at the same time - before we knew that it might be an issue - Both of them leaked so I figured it was worth while to swap 'em out.

As for draining the sludge out of the tank that is an excellent idea. Only problem right now, is that the PO had the tank stripped & dipped, and it was all done with the drain plug in - so it is not going to be easy to get out! (MooseCruiser tried yesterday) We will have it up on the hoist tomorrow so will take a better look at it.

Thanks for all the tips & pointers thus far... :beer: for all of ya.
 
..... If you had air coming in, you'd be getting white smoke at startup.

Strange!

I'd associate white smoke on start up with a glowplug problem and not air.

And in my cruiser (and similar), I think the best way to confirm air entering is by confirming that you are able to purge some out (from a bleed nipple) using the primer pump. (And air contamination normally causes my engine to "konk out" and I'm unable to restart it until I've purged that air.)

But I've realised that some cruisers behave differently. Perhaps those with a "bleed line running right back to the tank" would behave quite differently from mine in this respect?

.......The brand new primer pump we put on is a bosch. I purchased a new one for his truck and a new one for mine at the same time - before we knew that it might be an issue - Both of them leaked ........

Which Bosch part number?

That's odd too - because I've been impressed with the el-cheapo Bosch pump I'm using. And I found the copper sealing washer that was supplied with mine was "perfect".
 
another 15 k tonight and no issues .primer does not leak and fingers crossed all is calm for now !
 
Great - now you'll have time to post up your freakin' avatar!! (I'm thinkin' it should be a jerry can?) :grinpimp::wrench::clap::wrench::flipoff2::wrench::hillbilly::wrench::doh::D it's ALL good!
 
White smoke can be a sign of bad glows and of water/air getting into fuel lines. Unfortunately you won't get one without the other (water vapor in air), if in small quantities. Air can also make the engine run poorly/miss which will cause unburnt fuel to exit the exhaust. I had an issue with this on my rig when I changed the glows. next up is a fuel line replacement!

K
 
My mistake - it's a "Bosch replacement"

eBay Motors: Mercedes Diesel Primer pump,Bosch Upgrade 300D (item 350104710173 end time Mar-01-09 08:14:38 PST)

Very nice to not have to un-screw it!! the pump is working fine, just the seal of the copper washer. We'll get it eventually!

By the way in which that Ebay advertisement is worded, I think one would reasonably expect that primer to be "genuine Bosch".

And it is common for Ebay traders to avoid disclosing "supplier part numbers" on their sites (presumable so you can't by-pass them easily or compare their prices easily).

But all the Bosch primers that I've seen display the Bosch wording and a Bosch part number on the actually primer and the boxes are yellow and covered with the Bosch logo. For instance these are ones I got from Autohaus Arizona: (I know - Why would I get mine from Arizona? Well you folks over there have such good vendor-competition and therefore such cheap prices!!!)

primerAutohaus.jpg

So I'm not saying that what you got definitely isn't Bosch or is poor quality - But I am saying that if it isn't Bosch then your supplier is dishonest (by placing deliberately misleading advertising).

:cheers:
primerAutohaus.jpg
 
I have an HJ 60 and if yours is anything like mine...

I know from experience it can take 30-40 km of driving with low power before you completely get rid of air, especially after a filter change etc. Also, if there is any restriction in the filter/fuel lines/tank before the lift pump, these trucks will get air in the lines. Not because there is an air leak, but because there is no fuel return to the tank and so the air just keeps looping back to the IP and takes FOREVER to bleed. Trust me, I have experienced this WAY too many times!

Moosecruiser, If you really want to be sure everything is ok, then remove your tank and clean it out. Guaranteed there is crud in there and is the cause of your problem. The injector cleaner probably freed it up off the bottom of the tank. DRAINING IT WILL NOT WORK TO REMOVE THE CRUD!! Don't bother, especially since the plug is hard to remove. You may cause more problems.

When you remove the pick up assembly, check your pick up sock. It too is probably plugged with crud. Replace it. The pick up sock (should) sits right at the bottom of the tank.

You may have solved your problem for now, but I bet it comes back. Cleaning the tank and replacing the filter is the best fix.
 

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