RIRAM

I have a 99 Ram that blew a brake line behind the fuel tank. So I removed the tank, replaced all the lines no problem. Reinstalled the fuel tank and noticed that the vent was not connected before... the clamp was there but the vent wasn't connected. (Rubber hose, 3/4') So I figured the dealer didn't put it back on when they did the fuel sending unit under warrantfree. I reconnected everything and drove away no problems...

The problem happened the next day when I went to fire it up... it cranked for 6-7seconds before I looked at my fuel pressure gauge and had none. I cycled the FASS pump again by restarting the key cycle and the pressure finally went up to 15PSI and the truck started no problem. Runs great... as soon as it sits, this keeps reoccuring.

So I took the fuel cap off of the truck, and the problem went away. Does this make any sense? Is this vent supposed to be off????

I tried switching the Fuel cap, but the same problem happened. I finally just crawled under the truck and disconnected the vent tube again. I imagine it will start fine, but this is yet to be confirmed.

Copenhagenjunkie

I believe there should be a small round filter/vent, like what is on the end of the differential vent tubes. It's a one way valve that will close if you roll over but stays open to allow air in when on all 4's or 6's if dually.

I could be way off on this though............


I remember, the one way valve is in the plastic piece that sticks out. I somewhat remember many moons ago that there were many trucks that had a cap that was not removed when building on this fitting creating hard starts. THere might of even been a tsb for this but not sure.

RIRAM

Update: Today I started the truck, vent d/c'd and it was the same hard starting. So, now to find out why. The truck is starting to get hard to start even while cycling the key now... The truck also sputtered a bit, at zero throttle and trying to go into idle from slightly elevated idle (In traffic) Never stalled.

I bought the new straps today for the tank so I'll be pulling the tank tomorrow and will be checking the tank more thoroughly.

At this point I'm starting to think the time frame is purely coincidental...

dozer12216

Air leak in fuel return line??

RIRAM

Serious question.. how would an air leak in a return line cause a problem? Doesn't that essentially dump unused fuel back into the tank?

I did have difficult time getting that fitting back on... but didn't think much of it.




Also, when I shut the truck down I hear the tank gurgling... for lack of better termonology. Can't say I've ever listened for it before so unknown if this is normal for it.

RIRAM

The more I read this the more I think I have a VP going :/ I thought I'd be ok having never lost fuel pressure. FASS installed at 30k miles.

Copenhagenjunkie

It it's the OEM vp then that is a possiblility, check for codes even if no CEL. Have you tried without the fuel cap on again? If after running engine you pull the cap and it sucks in air then the tank vent is a likely source.

dozer12216

Air leaks in easier than larger fuel molecue can leak out. This alows reture line to drain. VP has to have fuel backpressure in return to light off.

RIRAM

Tomorrow I will check for codes. It is the original VP, but problem free till 2 days ago. The vehicle is hard start with the cap off... so a vacuum seems out of the equation at this point.

The fuel return line is a possibility. When I took it off it was rusted as all hell. Possible it isn't seated right... think it's possible to get air to the motor that quick from the tank?

RIRAM

Checked for codes. None Current/pending or historic. Today I dropped the tank and found that the fuel return line was kinked and wasn't installed in the steel tube properly. I cut out that section of line and made a new plastic hose with a new fitting for the steel line. So far it has started perfect ever since. But I don't consider myself out of the dark yet... I'll post back later on tonight after going out to eat... if it doesn't do it by then I doubt it will do it again.

RIRAM

Well, truck didn't want to start again... so I crawled up under the bed and watched the fuel lines leak at the metal lines going into the tank when the truck was shut off. So I need to order those lines. It was a stream of fuel when it was shut off.

RIRAM

Looking to buy the supply and fuel line fittings on top of the fuel tank... Dodge is telling me I have to buy a whole new tank... I heard there was an updated plastic fittings... is this true?? If not where can I get this part?

RIRAM

http://cgi.ebay.com/ebaymotors/Dodge...Q5fAccessories

If anyone has had the tank apart.. is this what the inards look like? Should I just try to win this then given it looks like what I think an updated plastic fitting type would be...

patdaly

You could do that module, or just get a Vulcan draw straw.

I have done them both ways.

Vulcanperformance.com

RIRAM

So the Vulcan draw straw came in today.. and it looks straight foreward... I just can't see how this will fix the hard start. If anyone can clear this up for me... this straw has 2 return ports.. I will be blocking off one port. The return fuel ports seem to essentially dump fuel right back into the fuel tank... I thought it may be a closed system and air getting in the return line would be a bad thing.. but if it's just dumping fuel into the tank.. what difference is it if it dumps outside (broke) or dumps into the fuel tank.. and then is able to take air in...

Am I missing something... or should I say is something going to become apparent when i open the fuel tank up.