joelk

I have pretty much determined that I have bad check valve in my fuel pump which is causing hard starting, with VERY long crank times.

I installed a FP guage, approx 40 PSI of FP with engine running, drops to zero in less than a second when shut off. I have lifted the fuel rails and observed injectors for about 10 mins with approx 40 PSI showing on guage (pressure maintained by applying 12V to FP prime wire) FP Regulator seems to function properly, pressure on the guage increases when vac line is disconnected and no indication of gas in the vac line.

Fuel filter is brand new, just changed and had no effect on symptoms.

Fuel pump is a Walbro 255 that I installed about 2 years ago. Started having extended crank times soon after the install and they eventually got much worse.

I have found a short term solution to the long crank times. I installed a momentary contact switch to supply 12 volts to the FP prime wire. If I hold the button for about 10 seconds, and then try to start, it fires up quickly and runs fine.

The car is a convertible and it is a total PITA to change the FP. I cannot change FP through an access hole in the "trunk" I know because I cut such a hole and tried.

I have read that an inline fuel check valve might be a solution to this problem. Would this solve the problem and if so, can someone please suggest a suitable valve (model, price and where to buy)?

Other than connecting and disconnecting factory couplers/fittings, I have not worked with plastic fuel lines.

How do you install such a valve in this type of fuel line/system?

Can you splice into the plastic line? If so, how?

If you can't splice in, how would you suggest installing?

I am only concerned about function, not appearance. Where would be the best place to install it?

Thanks, Joel

Injuneer

Kinsler sells inline fuel check valves.

http://www.kinsler.com/

They are NPT threads, so it would take some plumbing to get them into the stock plastic lines.

May help, but it would appear to just be making the problem smaller by moving the pressure problem closer to the pump. Getting a reliable pump might be a better fix.

joelk

Thanks for the link to Kinsler.

Obviously a good pump with a good check valve would be a good fix but it is a bunch of work and a fair amount of money to replace the pump.

Am I wrong in assuming that putting a check valve in the line will be a good cure for the problem. I am thinking (perhaps incorrectly) that a check valve, anywhere in the supply line should keep the line full between the valve and the fuel rail by blocking the fuel from draining back and by creating a vacuum, it will keep what is between the valve and the tank from draining back.

Have others sucessfully use an inline valve to cure this problem?

How do you go about plumbing a valve into the plastic line?

Guest47904

Under the vehicle, the plastic lines change to steel lines and run the entire length of the car.

This is where you could splice in the check valve. Cut out a small piece and carry it to the local hardware store. Find a fitting that will have compression on one side in the size of the line you need to connect to. On the other side you want it to be the size and type to connect to either 1/8 NPT or 1/4 NPT to match up with one of the small check valves like Kinsler has. PN either 3048 or 3049.

One other point. It will only take a short time to install it however, be sure the tank is near empty before you do. It wouldn't be a bad idea to install a shut off valve while you're there. Then it's a piece of cake to do maintenance work later on the fuel system like changing the fuel filter etc....

joelk

I'm on a business trip so I can't look under the car right now, but I changed the fuel filter fairly recently and my recollection is that it has plastic line on both sides of the filter. I'm almost certain that at least one of the lines at the filter was plastic, the line from the filter forward. Is is steel from the filter back to the tank?

If I don't have steel lines to splice into, can someone tell me how to splice into the plastic line. Is it like PVC plumbing and you just solvent weld fittings onto it? If so, where can I get the correct fittings and solvent?

And, I'll ask again, will an inline check valve fix the problem I am having?