Mk1 fuel check valve ?? Engine cranks not starting.

[kaneb]

Hello,  so I've determined that after my bunny sits for a bit the fuel drain backs to the tank then it cranks doesn't start.  My question is where is the check valve?  I have Been under the impression it's in the fuel tank.  What is the best way to get at it?  Pull the tank?

Any help is appreciated
Thanks,
Kane

[maxfax]

There is no check valve on a MK1 AFIK.. Never found one or have seen reference to one anyhow..  It is possible that you either have an air leak somewhere, or a weak lift pump..  Leaks on the pump and the return side of things can cause issues as well, but I'd imagine you would have noticed anything like that by now.... Restriction is possible (how's the filter?) but I'd think you would have some power issues as well..

How long is "a bit" ??  

[CRSMP5]

http://www.vwdiesel.net/forum/index.php?topic=30047.0

[kaneb]

New lines installed, new filter, stop solenoid checked,  new ip put on.  So am I guessing it's algae now in te screen?  Pretty much fuel behind the filter drains back to te tank once it sits for a while and car just cranks and will not start. 

[8v-of-fury]

If the pump can eventually pull fuel up to the motor and run.. then it is unlikely there is an algae problem. What is more likely is that you have a leak between the tank and the tank.

You need to go over every connection and piece of fuel line and make sure they are air tight and not leaking air in to the system. Either that, or you could install an electric pump up beside your fuel filter.

This way, you wont have to worry about ever loosing prime in your IP ever again. I have just recently gone through what you are currently experiencing.. i said F-it and just put an electric in. Problem DONElol.

[92EcoDiesel Jetta]

If your IP was just rebuilt, you have to assume it is leak free. Test every hose and connection break between the IP and the tank sender pickup and return with a MityVac to find and fix where the leak is from. Don't forget to check the inj return lines, they can let air in too. While your at it, MityVac test your IP too. I should hold vac. Putting an elec pump is just a band-aid IMO.

[8v-of-fury]

I feelthe electric pump is more like a antibiotic gauze bandage in that it effective at more than just stopping run back issues.

It will eliminate priming the pump and killing your battery, when the fuel runs back, you run out of fuel, you ever need to crack the fuel lines off and let air enter the system. It also helps the pumps maintain the same advance while in the higher rpm's.

Yes, you should fix the leaks.. But adding this as well is a very very worthwhile upgrade for sure.