Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

[RadioNut]

I have a 1996 Dodge RAM 1500 CNG only pickup that came from the factory as CNG only. Last night when I started the truck up at the grocery store, there was a loud hissing sound coming from under the bed of the truck. I was able to get home and after some looking aroung under the bed it appears that the pressure regulator is bad. I checked with the dealer here in town and the unit is obsolete (no surprise). Where can I find one and is it something that I can install? Please educate me about this!

Thanks,

RadioNut

[Highmarker]

Re: Where/how to replace bad presure regulator

RadioNut,

I have moved this thread into the vehicle discussion section of the site. I would try and get as much information off of the old regulator as possible. Maybe there is some company info on it of who made it and a part number. I am not familiar with the Dodge CNG vehicles, but there are people on here who are.

[RadioNut]

Re: Where/how to replace bad presure regulator

The Chrysler part number is 5189130AA. it still shows up on their computer but is obsolete and not available. Hope this helps someone.

RadioNut
Spanish Fork, Utah

[cngsteve]

Re: Where/how to replace bad presure regulator

RadioNut,

Send me a Private Message; I may have a source for your regulator.

Steve

[Lancer Automotive Group]

Re: Where/how to replace bad presure regulator

If you still are having trouble we may be able to help locate or change it for you.

[BRodri]

Re: Where/how to replace bad presure regulator

i know this sounds dumb but did they tell you the name on the part or just the number. if you are talking high pressure i have 2 spare pressure regulators. one is an impco and one is a modern engineering Co. Inc.

[madrugon]

Re: Where/how to replace bad presure regulator

Hi there , I have the same vehicle Cng Dodge ram 1500 5.2 L

And I'm having problems wit the regulator too. I did remove it clean it an still not much difference. However, I found there is a way to adjust it .
My problems with the GFI regulator is not resolved but this helps when It gets out of control. i twist the screw right or left as i listen to the reaction ( 1/4 of a twist is normally enough) you will need an Allen key
Remove first screw in order to get access to the real screw - adjuster
it, is located in the opposite side where all hoses are ..
Yes It is within a tiny hole in the very tip of the regulator .
This might solve the problem ..

Removing the Regulator

- Turn off the tank valve and let the car runs until there is no gas in the lines
- Remove water lines
- loosen up the gas inlet pipe
- Remove the bolts that hold regulator to the chassis 3 bolts
- unplug the shutoff valve
- Move regulator away from chassis and twist it to free it from outlet gas hose( wrench might be necessary for initial turn )


You should have the regulator in the work bench by now

It will take you about one hour the first time


I have some question myself..

Does any body have remove White cap from a GFI regulator? .... Because i couldn't do it . Does anyone knows how to do it?
Is there any replacement parts for this regulators ? Diaphragm , etc
written manual in pdf would b e great .
Will an Impco regulator work for this vehicle HPR3600

Regards Josh

[larrycng]

Re: Where/how to replace bad presure regulator

Personally I wouldn't mess with a GFI regulator.

As long as you know what the pressure setting is suppose to be (110- 120 psi I think) you could replace it with anthing that has flow capacity (BTU's), adjustment, heating capabilities.

As for pressure adjustment, use a good pressure gauge and make the final adjustment in the pressure increasing direction. There will always be a slight pressure drop between idle and WOT. Watch your fuel trim numbers, it they over + or - 10% you may be too low (+) or too high (-).

I would replace the regulator if you have to keep adjusting the pressure to maintain normal engine performance. Impco or Conoflow are my favorites.

I'll attach a couple of pictures of the GFI reg

Have fun
Larrycng

[larrycng]

Re: Where/how to replace bad presure regulator

sorry about the pictures
I'll try again


larrycng

[madrugon]

Re: Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

Larry,
Thanks for the pics , there are some of them that doesn't appear clear ( maybe size file too small) .. Nevertheless, I was thinking about replacing it with an Impco HPR 3600
My guess is I should put a shut off valve in line with the regulator given it doesn't seem to come with one .
The Impco regulator has a nominal outlet pressure of 150psi +/- 20 psi which leaves me with the uncertainty ...

150 psi -20 psi adjusted = 130 psi

My vehicle's GFI regulator is a 120 psi
Should I give it a try ?
One thing i notice is the shut off valve is sometimes very hot . ... I wonder if this is causing the problem..

[larrycng]

Re: Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

They will run hot. See if there is a current rating on the coil housing. When the coil is cool check resistance using a good ohm meter -- then do the math with ohm's law. Remember resistance increases as the coil gets hotter and reduces current flow

If they are close you are ok. Remember system voltage is 13.5 to 14v.

larrycng

[madrugon]

Re: Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

i 'm quite happy because i found some good info ..

http://rds.yahoo.com/_ylt=A0oGkxNzGglJ7b8Ard1XNyoA;_ylu=X3oDMTEzYXM2azQyBHNlYwNzcgRwb3MDNwRjb2xvA3NrMQR2dGlkA00wMDFfMTAx/SIG=12ii3sb0f/EXP=1225419763/**http%3a//www.dacooley.com/RamStuff/1997/maintenance%2520info.pdf

I fix the link .. sorry to those who intended to view the file and couldn't do It.

this is a Chrysler manual for the ram 97, it gives you details about the cng system go to the bottom of pdf document

The good part i didn't know where the regulator's filter was located and this service manual shows it clearly yupi!

[BRodri]

Re: Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

Ok right now on my 350 small block from a impco HPR3600 i am running 85 psi. it is adjustable. and it runs just fine why would you need it to be at higher pressure? would it help anything? maybe top end power? just thought it might help.

[madrugon]

Re: Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

I must say that cleaning the filter (which is located right at the entrance of the high pressure port ) has made a difference... Nevertheless, happiness isn't everlasting though.
At the time i had begun to feel proud of my work ....the engine stooped O shucks!
I started It and lasted about 2 seconds before i had to re-start it again ... So went to fuses's box underneath the hood and move relays around( ASD relay ) besides that I unplugged the Low Pressure Sensor in the fuel rail and walla!


It is running great knock on wood

I did an unorthodox modification to the water lines by adding 2 ball valves that eventually will facilate removing regulator without the antifreeze mess associated with it . I forgot to mention because the lines were bad I replaced them both with an orange brided hose ( the ones used for air compressor and rated to 300 psi) Great fix!

Regarding the Impco HPR 3600..It looks it will be a good substitute.... The GFI regulator that came with this dodge says 120 psi nominal outlet pressure while the Impco's manual states 150 +- 20psi
I wonder if a higher pressure will harm injectors? I doubt it..
Volume capacity seems to be about right..
Brodri,
I saw you have one for sale.... is it new ? and at what price would you sell it for?



Does anyone know about the ASD relay implications with the transmission .. I've noticed that when the problem gets worse the best thing is: to shift to neutral gear and then try to start it ..
My guess is the asd relay blocks the current flow to solenoid high pressure valve, other possibility would be the solenoid HPV is going bad intermittently
Anybody knows better?

Cleaning of Injectors and complete tune-up was performed last month!




Regards Josh

[larrycng]

Re: Where/how to replace bad presure regulator {1996 Dodge RAM 1500 CNG}

The higher pressure shouldn't harm the injectors. You may get a check engine light for fuel trim out of range. With the higher pressure the fuel trim will go to minus side indicating the system is subtracting time from the injector pulse width (leaning it out). The higher pressure is causeing more fuel to be delivered to the cylinder causing a rich mixture.

Those filters in the GFI regulator are not designed to be cleaned -- good going

Larrycng