Fuel ring check valves

[Intrinsic]

I am running the Ford Ranger Airtex fuel pump, and when I shut off the engine the fuel pressure drops resulting in the need for multiple starts to re-pressurize the fuel ring.

I would like to install a check valve(s) to preserve pressure in the fuel ring when the pump is not running.

Are there any recommendations for which check valves to use, and where is the ideal locations to place them? Also will I need one valve after the pump, or two valves with the extra one on the return line after the regulator?

Thanks

[Max Welton]

I'm also using an airtex pump and have no problem restarting. The second or so it takes to repressurize may not be the cause of the problem you are experiencing.

Also, if the fuel ring remains pressurized be careful anytime you need to open it up (for example, to replace the hoses during pmi).

Max
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[raygreenwood]

If this is D jet...or any EFI system for that matter.....the ring main is supposed to stay pressurized. If not, any fuel evaporation forms bubbles usually at high points and in the injector feed tubes.

All EFI fuel pumps should have a check valve on the outlet port. Some specific pumps like those for CIS (Bosch 044 and others) use a screw in check valve between pump and line.

If you have a pump that is relatively new and has no rust damage at its check valve then you either have leaks (hose connections or injector drips) or you have a bad regulator (usually the main cause).

The fuel pressure regulator IS a check valve and is the main check valve at the end of thee ring main. It keeps pressure between the head of the pump and the check valve.

In generaal...regardless of pump brand...original Bosch or Airtex etc.....if you are running 28 psi and you shut the engine off, the fuel pressure should instantly drop to between 21 and 23 psi.

It should stay in that range in general for about 45-60 minutes while slowly bleeding down. Usually within an hour it will bee in the 18-20 psi range.
Overnight bleed down should leave you with...in general...about 13-15 psi on the ring.
10 psi is about the minimum (depending on pump volume used) where the stock pump can get you back up to the low 20's psi in the 2-3 seconds the pump buzzes when you turn the key.

In normal spring, summer and fall weather a well tuned engine will start just fine in the 10-15 psi range....however if its very cold outside....the poor atomization from a system that bleeds down to "0" overnight and only gives 10-12 psi on the 2-3 second fuel pump buzz....can leave you cranking several times. The atomization is already poor in two ports with D-jet because of the injection timing issue.

If you can get this straightened out and have better than stock fuel pressure stability (which was just adequate...not great like new car fuel pressure stability)....and you tune D-jet well and the engine is in great shape......your engine should start....with less than 1 full rev of the engine even down to the teens in outside temperature . Ray

[Donnie strickland]

[raygreenwood]