Fuel tank vent valve

[negativentropy]

Hi, I'm living at Big White near Kelowna for the winter have been having a lot of difficulties starting my van. I ordered a good set of glow plugs, and that made a noticeable difference at first. When I swapped the plugs out I also changed my fuel filter. Following this I took a road trip during that cold spell in January (-25C). The van really didnt like this and I had to turn the engine over for a long time before it would maintain an idle without stalling. But the way the engine sounded I felt it was starving of fuel. I checked the fuel filter and sure enough I had to pump out air from the system even though I had done this when I changed the filter. This kept happening and after I'd pump out the air from the fuel system the van would start reasonably well - so somewhere air was entering the system, although I was certain I did a thorough job of changing the filter. Then a couple of weeks ago I was filling up the tank - I had done a long stretch of driving, going from a full tank to nearly empty. When I took off the cap I heard the sound of air rushing into the tank.

This morning I again had a hard time starting the van, so as usual I went to the fuel filter and bled the air from the system - this didnt work as it normally does. So I opened the fuel cap, and again I heard the sound of air rushing into the tank. I tried to start the van again and it started instantly, the best start I can remember this winter.

Is there a valve or vent that allows air into the fuel tank to prevent a vacuum from forming? I figure this is what has been starving the system of fuel on start ups...

Any advice, similar experiences...?

[jessef]

there is a vent tube just like most fuel tanks on vehicles

look in the wiki for the exploded fuel system diagram and follow the vent tube. Check to see if it's plugged. Also check the fuel lines at the injection pump to see if the clamps are holding (loose = air) or if the lines have collapsed.

[negativentropy]

OK and update on this situation...

As of now I simply cant start the van. The problem appears to be getting worse. Here is some info:

Altitude: 1500m
Average Temperature: -5C
Exhaust is white and there is a fair bit of it.

I talked to the mechanics at our snow groomer shop - they said the fuel tank drawing air when you open it is normal. Given the description I gave them the mechanics figure air getting into the system somewhere before the fuel pump, or even before the fuel filter.

Whatever the problem is, there is always air in the fuel filter that I have to pump out if the van has been sitting over night. Once the van does start it runs just fine, no rough start, no lack of power...

So today the van wouldnt start, even after purging the air out of the system. So I reinstalled the fuel filter, taking extra care to put oil on all the o-rings and to tighten everything well, perhaps something was not properly installed... And still nothing. I stopped trying to turn the engine over before I drained the battery. I will try again later this week when the weather is warmer.

This whole problem started when I moved to Big White in November and I changed the fuel filter. I think my van just really doesnt like the winter... Also, I filled the tank yesterday and I think Kelowna has switched back to summer fuel...

Any suggestions - GAHHHHHHH?!?!

[Diver]

A couple of things spring to mind. Firstly, are you sure that you have the correct fuel filter? It's been recognised over here for some time that there are two varieties fitted. One has a single seal the same as the vast majority of diesel filters, the other has an additional smaller seal in the centre. Problems have been caused by fitting the double seal kind to a single seal type pump head - air is sucked in past the outer seal. The ring holding the inner seal is simply pulled out and problem solved.
Secondly, I had a similar problem with a Toyota Townace recently, it just wouldn't start in the morning. Turned out to be full of air in the fuel filter too. No amount of pumping would bring the fuel up so I swapped out the pump head for a used one which worked as far a bringing the fuel up, but it still syphoned back into the tank overnight meaning it had to pumped again in the morning. I fitted a non-return valve in the fuel line and problem solved.

HTH

Jason.

[rezdiver]

is the drain on the new filter closed? or maybe not seated properly? did you take off any fuel lines or bump them around during the filter change so that they may have cracked or come unseated?

[negativentropy]

There is no damage that I can see visually to any parts. I did notice yesterday, but I'll have to double check, that the old filter has the double seal you mentioned, but my new one only has a single seal. I thinking of throwing the old filter back in to see if the new filter is what is causing the problem.

[negativentropy]

OK so I swapped out the new fuel filter with the old one. No change, the van still wont start. On the advice of a knowledgeable friend I will test the fuel shutoff solenoid...

Any other suggestions. I'm desperate to get the van running, even if its a temporary fix. I'm moving to the island in 2 weeks!

[rezdiver]

have you cracked(loosened) your injector lines at the injectors to reprime them after running the pump dry to make sure the injector lines are flowing diesel?
your Injection pump may just not be priming without some help.

[Diver]

Yeah, the Townace had to have not only it's fuel filter filled with diesel before screwing on, but I also took the fuel line to the pump off at the filter and elevated it above the engine with a funnel (with a gauze in it as you obviously don't want any crap entering the pump). Filled the funnel with fuel and got the engine running gravity-fed, switched off, reconnected the fuel line to the filter housing and started fine after that. That's if your primer pump on the filter isn't working. Worth checking the fuel solenoid too of course, but it seems your problems started with changing the fuel filter so trying to think of things related to that to begin with.

[negativentropy]

I will try all these things tonight and give you an update on what I find.

If the fuel shut off solenoid is stuck in the closed position is there a way to repair it?

[Diver]

Usually replacement is the go, from memory though I have a feeling that it separates into two parts so maybe fixable if the plunger is stuck.
You already know that there's more than one solenoid on the back of the pump and the one you want is the lower one surrounded by the injector pipes right? Easy enough to test once you've got it out by earthing its body and putting 12v +ve to the terminal and watching for the plunger to withdraw.
Maybe worth (carefully!) trying the gravity-feed method first though as it's quick and easy?

[jessef]

You can try what I suggested in the other thread (same issue)

http://www.delica.ca/forum/nearest-deli ... 12919.html

Bypass the stock filter and install an inline pump. This will allow you to troubleshoot the fuel system more thoroughly by process of elimination instead of hunting the leak.

[negativentropy]

jfarsang your suggestion is a good one and I would try it if I had more time - but I need this van up and running soon, so if I cant fix it myself with the handful of tools I have then its going to a professional mechanic. I hate to do this, I'm usually a do-it-yourselfer, but not this time around.

I'm going to test the solenoid tonight, and if that turns up (OK) ill crack the injectors and try to bleed the system some more. Then I'll wait monday (+10C forecast) to try and and turn the engine over again.

I need this vehicle to make the trip from Kelowna to Campbell River in two weeks from now. After that it can sit in a mechanics shop for a month for all I care...

[jessef]

All you need is a 7-8 psi inline 12v pump, switch/wire and an inline filter.

You can buy this from any auto parts or general Canadian tire store.

1 hr tops and you're golden.

[negativentropy]

OK so the results are in...

Took off the intercooler, searched for the right solenoid.
Eventually found it with the help of pictures and diagrams I found online. God its a tight squeeze back there.
Switched the ignition to "ON".
Removed and applied the negative battery terminal repeatedly, listening for the solenoid. It was hard to distinguish from the other clicking sounds going on, so I put my fingers on the solenoid and could not feel any movement at all when applying and removing the battery terminal.
Next with the battery hooked up I applied my volt meter probes to the solenoid terminal and injection pump body. (as instructed in the shop manual) This gave me a 12v reading, so I knew the solenoid was being powered. Next, without moving the probes I switched the volt meter to measure ohms, and there reading was infinity. According to the shop manual the reading should be between 8-10 ohms.

Conclusion, the solenoid isnt working. Correct, or have I made a mistake somewhere...?