sjalbert

Many Thanks. Just to make sure that I'm on the right track the check valve that keeps pressure in the fuel rail is part of the regulator/filter?

CCKen

Yes. And there's a second check valve integral to the pump.


Here's some pics of inside the regulator/filter:

Indyclassic

ok, now I'm confused. Are you saying there are TWO DIFFERENT check valves that hold the fuel pressure to the rail? ONE in the filter regulator AND one in the PUMP???

If, having the problems that I have, I just change the filter regulator that you suggest, W/OUT changing the pump module will it fix my hard start problem? or do I need to replace the whole pump b/c of a second pressure regulator?

CCKen

First, I'm not suggesting that you change the filter/regulator. That would be your decision.


There are two check valves but the one in the regulator is the one that commonly fails.


If you hook up your pressure test gauge at the rail and pressurize the system, then shut the pump off and the pressure drops relatively fast, it's the check valve in the regulator. The pressure in the rail will drop to zero eventually but should hold down to 30 psi for 5 minutes.

Ralph77

To CCKen:
Thank you for the most excellent write up. Been saving money for a new pump, it is not an issue, it is the check valve that is so so. Might just do this and replace the check valve. Cause if I drop the tank I have to buy new straps, maybe replace a couple other things in there too. Would just seem a waste not too if you are already there to replace the whole pump.

CCKen

I'm not a proponent of just replacing the regulator/filter.


There are filters in the module besides the regulator/filter. If you are going to go to the trouble of doing the access mod you would be better off replacing the pump module, especially if there are a lot of miles/years on the pump module.


Even if you are going to drop the tank, replace the module.


Don't penny pinch, install a Bosch or Carter module.

Ralph77

Thanks for the advice. Thankfully this is not an issue with the exception of turning the key on twice to prime the pump when is sits for an extended period. Like overnight. Holds a steady 49lbs when running. So no rush. Been throwing $10/week in an envelope just for this. This is how I save up for all the parts I need/want to replace on the Jeep.

CCKen

^ good on ya.

97grand4.0

Turning the pump on twice to prime it means either the pump is failing or the filter in the filter/reg is plugged. Means it can't come up to pressure. We're not even to the point where the regulator is working yet.

Ralph77

Little confused.

sjalbert

I'm pretty sure that mine's a check valve issue also, but I'm with CCKen, my 2001 has 220k miles. When I do this I'm going to replace the whole pump assy.

Ralph77

Everybody is talking about the this on top of the fuel pump assembly right?

CCKen

I think you might be confused mate.


If having to turn the pump on more than once indicates that the fuel rail pressure has drained off as well as the fuel in the rail. Normally pressure will drop but fuel will remain in the rail/fuel line to the tank, so just turning the key to ON, in a tight system, will immediately regain pressure in the rail.


The filter has nothing to do with this.

CCKen

Yes.

Basslicks

This entire thread is making me thankful I have a 92