Engine/Transmission (1994 - 1998) high fuel pressure @ idle

[bowhunter]

Checked the fuel pressure today. It was 38-39 lbs @ idle and 41 ilbs @ 2000rpms.



The return line is new and is not kinked. Everything looks right.



Is this a bad overflow valve? I stretched the spring last fall to get by without buying a new overflow vavle.



Do I need a new overflow valve? I also still have the ticking noise, which is why I started checking fule pressures anyway.



Any ideas?



Thanks

 

[illflem]

Your pressure is way too high, probably stretched the spring too much. Look for 20-24 at idle.

 

[bowhunter]

illflem-



I checked the spring. Its below the . 550 spec. Is been over a year since I stretched the spring.



Do you think a new overflow valve will solve the problem?



This is the original overflow valve.



Thanks again

 

[Andy Redmond]

I installed one last night on a 96 auto trans.



Before 8 psi at idle, after 25 +/-. It would only do about 18 psi at high idle no load before and now 25-30 psi.



So yes, I'd guess this would fix you up. After disassy of several high mileage ov. flow valves, I've seen pitting on the chk. ball etc. Perhaps both the ck. ball and valve (seat) are worn and its sticking.



The reason we don't want to much pressure is that its hard on the lift pump and will lead to its early demise.



The latest greatest pt. # are:



3932096 Cummins; 4883838AA Mopar; Bosch 2417413093, not ending in 086.



Good luck,



Andy

 

[illflem]

Another reason you want lower pressure is that you're tempting fate with a leak springing anywhere on the pressure side of the lift pump, this includes blowing out filter gaskets. At $55 http://www.piersdiesel.com/DodgeUSPrice.htm is hard to beat.

 

[bowhunter]

thanks for the help.



I'll get one ordered from Piers... I need to get a downpipe for the new HX40 anyway.



Thanks again

 

[bighammer]

A local shop has them for $15



The brand name is Flag and it's set for 30 psi

 

[Dbonzi]

I've got a 96 2500 215 pump, where is the best place to connect the gauge to test fuel pressure?

Thanks in advance

Dennis

 

[illflem]

I drill and tap the top of the injection pump banjo bolt to 1/8'' pipe

thread, then install a male x female 1/8'' needle valve with 1/8'' tubing

compression fitting in it. Boost gauge or oil pressure tubing pushed though

some 1/4'' tubing to protect against cuts and kinks to the gauge. For a

gauge you can use a fuel, boost or water pressure gauge. I use rear

connected, liquid filled, stainless water pressure gauges and make my own

mount. They have no lighting but it's not a gauge you need to look at all

the time. They can be mounted low for the same reason. Some folks use boost gauges, it needs to be 40 psi minimum. Use no Teflon tape,

it doesn't work with diesel. Instead use anti-seize or Permatex #2. Remember

you are working on the clean side of the filter, keep everything spotless.



If you can tap your manifold for a pyro tapping the banjo bolt is a piece of

cake. Just drill from the inside to keep the

hole straight and tap from the outside. You can also connect to the fittings

on top of your fuel filter with the appropriate adapter to tubing if you

don't want to tap or want a pre-filter reading also.

After the install start your engine with the needle valve closed then open

it slowly till someone in the cab signals you that it's just reading

pressure. If you tighten down the packing nut under the valve handle the

setting can't move. The valve will control pulsation and buzzing and can

also be shut down in the unlikely event that you have a leak.



Parts list; 1/8'' needle valve - $4 from the hardware store, plastic oil

pressure tubing kit that comes with the compression fittings - under $10

from an auto parts store. 1/4'' tubing for protective sleeve - less than $2.

Gauge is your choice and may come with tubing. The water pressure gauges I

use cost less than $10, bringing the total cost to less than $25 and a

couple hours of your time.

I have several gauges that have been in service for over 5 years with zero

problems though you may have occasionally close the needle valve a bit more

if the gauge starts pulsating.

 

[Todd T]

hey, Bowhunter. Gateway Cummins sold me one for $60 after i told them no thanks at the $80 they first wanted. i told them i could get one for $55 and they folded. 60 bucks to take it that day was worth it to me.



just a thought

Todd

 

[Todd T]

while on the topic can someone to speak to the part they had that was superseided? it had a ball in the top and was only $51



would one of these work for us TOO and does anyone know the pressure setting for that one?

 

[illflem]

I think the only difference is the old one can be taken apart, the new one not. Pressure is the same.

 

[Dbonzi]

Thanks Bill

Looks like I'm off shopping this weekend.

I appreciate the lengthy post. I'll print it out and take it right out

to the shop with me.

Thanks again Bill



Dennis