Engine/Transmission (1994 - 1998) Overflow Valve?? (Hard to Start)

[NevadaBadBoy]

Hello again.

I've been reviewing all the messages that dealt with the Overflow valve on the 12 valve engines. While some messages pointed towards the rubber fuel hoses, the other few were aimed at the overflow valve on the inj. pump. I've checked out the return and inlet hoses and they were still solid from the first time I had them replaced (1997 or 1998). My concern is that how can I still loose my prime if I have the Prime-Loc Kit attached to my fuel system. If this check valve is located behind the prime-loc, how can I still loose prime? Shouldn't the leak be prior to the Prime-Loc?

Before I spend the $55 for a new check valve, I want to make sure that it will fix my problem (hard to start).

It doesn't always loose prime, though. The tank could be full, nose pointed downhill, and I still have to crank for several seconds before it comes to life. Back when the fuel hoses were bad, the loss of prime would only occur when the nose was pointed uphill and the tank was less than half full.

Do any of you have a Prime-Loc installed and had this intermittent check valve failure?



Going to be busy for the next 2 weeks. Expecting the Kelderman Air Ride suspension sometime this week. Also need to level another 200 sq ft of land out in the hills of Elko, NV. Bought 163 acres several years ago with the intention of living there. Closed escrow on some prime commercial property here in town 2 weeks ago and placed an order for some steel buildings (house and garage). Rented a D8 Cat with a ripper for next Saturday. Only going to cost me $125/hr, and that includes the driver, delivery and fuel. Should get the pad leveled in less than 10 hrs.



Back to my main post... .

If you have had similar problems that I am currently experiencing and have solved them, I'd like to know what it was and how you fixed it.



Thanks,



Martin

 

[Joe G.]

The first thing to do is check your fuel pressure. It should be about 20 PSI at 2000 RPM in neutral. If it's not then there is a leak down somewhere. Probably the overflow valve. I don't trust the Prime-Loc filter business. Too many extra hoses and fittings that could cause problems. The stock filter is real easy to change if you remove the two nuts that fasten the master cylinder to the booster and lean it toward the fender.

 

[Deezul1]

pull the spring from the overflow valve and measure it. it should be at least . 500 if not stretch it to . 550 and see if the problem is solved, if so get one.

 

[wcjp]

Where specifically is the overflow valve?

 

[Joe G.]

The overflow valve is on the engine side of the pump even with the forward (#1) delivery valve. It looks kind of like a banjo fitting.

 

[bighammer]

Overflow valve is pretty cheap and easy to replace. Hopefully that is it.



There are also check valves in the lift pump that can go bad. Lift pump was about $150 and a bit of a job. (tough reach) I removed the fuel fiter housing and went over the top.



I didn't know it was bad until I changed the filer and couldn't re-prime.

 

[NevadaBadBoy]

My lift pump started going out on me in 1998. Now that was a PIA to replace. The pump was starting to show some leakage around the weep hole. Cummins said that they have revised the components inside the pump to make them last longer (different materials maybe??). Pump looks good and runs fine.

I haven't dialed in the fuel pressure yet. I'll check the spring lenght this weekend, if I have the time.

Strangely enough, truck has been starting just fine for the last 3 days.



I'll keep you posted on my progress.



Thank you for the suggestions.



Martin

 

[The patriot]

My truck was hard to start after I had the idle cut back a bit. I just put my foot lightly on the petal when cranking and viola, starts on the first revolution.

Watch the length on the spring. I did mine to . 500" w/o bothering with a gauge. When I finally got a gauge on it, it was at 37 PSI. :--)

I THINK the . 500 reading should include all/any shims you might have because I pulled all my shims out after seeing this reading, and it's within spec now. I can now add shims as needed at a later date.

Eric

 

[Deezul1]

The info I got on spring length was . 500 for the spring only. You can always remove shims for less pressure.

 

[PUMPERDUDE]

Lets see,

1994 Ram,135k +miles..... I'd change that overflow valve. My 95's spring came out in pieces about a year and a half ago. Just pull it out to check it . Also check out your shut down solenoid to make sure its not falling apart. (the boot). It can start hanging up causing intermittent problems. Good luck

 

[NevadaBadBoy]

PUMPERDUDE, thanks for the latest idea (shutdown solenoid). I haven't considered that angle. If the spring was broken, were you able to fish all the fragements out? It didn't screw up your pump, I hope.

Monday I got lots of smoke (blue) when it finally did fire up. It was definitely air bound; was running on 3 cylinders for a few seconds, then the other ones got some fuel.



My idle is turned down low, and when it gets really cold outside, I have to feather the throttle a little. After about 15 secs I can remove the pressure from the pedal again. After another minute, I turn on the fast idle and the A/C.



Received the Kelderman AirRide today. The air bags are quite large, the air tank even larger than I expected. I also ordered the auto-leveling kit when I placed my order. Can't wait to put them in. The hardware looks well made (nice weld job). I'll let you all know how she rides when it's all buttoned up. Give me another 2 weeks. I'll be out of town Friday. 0 degrees in Elko already. Got down to 22 below last year. Talk about a hard start. Cycled heater grid twice and she fired right up (with the help of my right foot, of course).



The check valve has been ordered from Pierce Diesel. $61 total. Should be here by Monday.



Martin