Low Fuel Pressure Light and Big Line Kit

[Tbird9140]

Greetings Guys.  Back again with more fun.   Just completed replacing tappet cover gasket, upgrading transmission solenoids et, al.  and pan gasket replacement with help of the site.  Thanks guys for all the assistance.  If these three projects were not enough pain in the ***,  I decided to replace the engine mount bushings and add a big line kit and a set of A Column gauges (egt, boost and fuel pressure).  Yeh, I know, a real masochist.  Anyway my truck (2000 flatbed, extended cab, 1 TN, 4WD with 325K miles) currently has an idiot light for fuel pressure which I originally installed a couple of years ago when I added a Raptor lift pump.  I would like to keep the idiot light just in case I don't happen to notice a falling needle on my new pressure gauge.  (See - they named the light after me!)  Everything went fine with the big line kit and gauge installation until I  got around to testing my handiwork.  The gauges work fine, but the low fuel pressure light does nothing.  I tested the light - good.  I tested the (+) lead to the light - good.  I tested the (-) lead to the light - NO GROUND.  Then it occurred to me.  When the Low Fuel Pressure light was originally installed it was attached to the Banjo Bolt and got its sender ground through the metal contacts to the engine.  Now  the sender is attached to a "T" in the middle of the rubber big fuel line between the filter and VP44, hence, no ground.  My big line kit replaces the Banjo bolts.  (As I understand it,  the low pressure sender internally is normally grounded but when it sees 5PSI (in my case) the pressure opens the contact and you have no ground contact between the sender threads and the wire attachment point to the low pressure light.)  In my case now since there is no ground to start with, my light never functions.  Then it occurred to me.  What if I can provide a ground to the sender threads then it would function normally?  So, now if I got a large ring wire connector that would fit over the threaded end of the sender and run a wire to the (-) battery terminal or another ground source, would not I solve my problem?   The new fuel pressure gauge sender 2 inches away has a ground lead and I might just tap into that. I would only have to be sure that when I tightened my sender into the "T" in the big line it made good contact/compressed with the wire ring and did not leak.  Has any of you gurus out there in Cummins' land faced this problem?  If so, how did you solve it and does my proposed solution make any sense?

 

Regarding the fun of my engine mount bushing replacements,  I will have to get back to you on that.  I may be over my head on this one.  If I get these done, I'm thinking of moving on to injectors and turbos.  Never a dull moment.

 

 

[Haggar]

Yes,  Provide ground to sender threads.   I played with large ring connectors and such.  Sometimes they work fine, sometimes not (npt threads don't end up in same place all the time etc.

I also got away with soldering it to the the brass tee and then screwing the sender into it.  Then grounding that wire.    sometimes you can find tees and elbows (made for plumbing) that have a tab with a hole (to mount to a wall stud)  that would allow you to bolt the ground to the fitting without drilling and tapping.

 

GL  HTH

Hag

[Mopar1973Man]

I did that long ago. Now I don't even worry... 

 

Yes I had a low pressure light too and had to solder a ground wire to the brass fitting to make it work. Yeah some time the solder would fail and the ground would drop off. Not a good solution. 

 

Now my current solution is a ISSPro EV2 fuel pressure gauge with a USB programmable low pressure light. So I plug in the USB cable and I can flash the fuel pressure gauge to trip the low pressure light at 13 PSI. There is several other functions like lighting, optional aux relay that is programmable. etc. These are the best gauges you can get. 

 

Old setup DiPricol mechanical gauge and my low pressure light.

 

Now the current setup...

 

USB cable... Ready for programming...

Edited June 10, 2021 by Mopar1973Man

[Tbird9140]

Thanks guys.  Next time ? I will buy a gauge (ISSPro?) with a warning light as an included component.  This time however I have already bought my Glow Shift gauges.    Following your responses, I prepared a 4 inch wire with eyes on either end.  One end goes around the idiot light sender 1/8 NPT and the other slips on to the negative pole of my gauge sender.  I had to put a washer over the idiot light sender threads between my new ground wire and the "T" as otherwise even strongly tightening the sender onto the "T" did not compress the ground eye sufficiently to always make a good strong contact with the sender housing.  Hooked it all up and now I have an idiot light for the idiot. Hurray!  One quick question here.  Should I be concerned about the air that got into my fuel lines during installation of big line kit and senders? Does cycling my Raptor, turning the key on 5-10 times for a minute without starting the truck likely solve all air problems?  Or do I need to bleed the system?  If I need to bleed, how so?  Cracking my injectors?  I'm doing all this to protect my VP44 and would hate to screw it up now because air damaged the injection pump  Cracking the injectors would only remove air after the VP44.  Again should air be a concern  or can it safely be "flushed" through the system?  I have not thoroughly checked any leaking on my mods as I am waiting to possibly address the entrapped air consideration before I pressurize the system.

 

One last issue.  Since my truck has about 325K on it and I bought the truck at 200K,  I have no knowledge of the age, size or type of injectors it is currently running.  I do have the impression however that it has lost some power in the last year or so. (Other than loss of power my truck does seems to run/drive fine - no excessive blowby, oil burning, or smoke, etc.)  I am therefore considering putting some new aftermarket injectors on it.  I may also upgrade the turbo.  I'm not looking to make a drag queen  out of the truck, only giving it a bit more oomp on those long 5% grades while towing my 28' boat or 5th wheel.  I am leaning to putting +75 to +90 injectors on it.  Do any of you have any thoughts on my plans, and/or what sizes, brands, or types of injectors I should look for, or stay away from?  Similarly, is there any combination of injectors and turbo which you have had good luck with and think I should consider?  I did up grade my 47re to twin disk about 75K miles ago.  Finally, if I do go with a mild power upgrade as discussed,  do I need to add a transmission temperature gauge or other monitoring sensors?

 

Thanks again guys.

[015point9]

The low pressure light... mine comes on at 5 lbs which is pretty well useless.  I installed an adjustable Hobbs switch and after messing with the adjustment screw  comes on at 12 psi now. Not sure if link is exactly what I  have but there's lots that are adjustable.  

http://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Product_Code=ATP-BCS-003&Category_Code=BCS

Edited June 10, 2021 by 015point9
Info

[Mopar1973Man]

21 minutes ago, Tbird9140 said:

Should I be concerned about the air that got into my fuel lines during installation of big line kit and senders?

No. The pressure gauge line will get air in the line even after being bled. 

 

22 minutes ago, Tbird9140 said:

Does cycling my Raptor, turning the key on 5-10 times for a minute without starting the truck likely solve all air problems? 

No. You need to tap the starter just briefly then it will start the lift pump prime cycle. Runs for about 25 seconds.

 

23 minutes ago, Tbird9140 said:

Or do I need to bleed the system?  If I need to bleed, how so?  Cracking my injectors?

Typically I crack 1, 3, and 4. Then crank it over till it nearly starts of the fuel can be seen from the lines. Then close them back up and startthe engine.

 

24 minutes ago, Tbird9140 said:

I'm doing all this to protect my VP44 and would hate to screw it up now because air damaged the injection pump  Cracking the injectors would only remove air after the VP44. 

Air just makes the fuel compressible. Since it can't reach 4,500 PSI it will never fire so you bled out 3 line and should make it capable of starting. Air is fine to pass through for priming purpose. 

 

26 minutes ago, Tbird9140 said:

I am leaning to putting +75 to +90 injectors on it.  Do any of you have any thoughts on my plans, and/or what sizes, brands, or types of injectors I should look for, or stay away from?

I'm running on my 2002 Dodge DAP (Diesel Auto Power) +150HP injectors. (7 x 0.010) popped at 320 bar. Then on the 2006 Dodge I'm running +50 DAP injectors (Common Rail). I've had super good results with the Diesel Auto Power injectors I can say all injectors are built in house and bench tested before sale. I would say between +100 to +150HP injectors are very safe. The only give is the Quadzilla tuner I'm running is keeping my EGTs down low and economy up just a bit. 

[Tbird9140]

Thanks guys.  Next time ? I will buy a gauge (ISSPro?) with a warning light as an included component.  This time however I have already bought my Glow Shift gauges.    Following your responses, I prepared a 4 inch wire with eyes on either end.  One end goes around the idiot light sender 1/8 NPT and the other slips on to the negative pole of my gauge sender.  I had to put a washer over the idiot light sender threads between my new ground wire and the "T" as otherwise even strongly tightening the sender onto the "T" did not compress the ground eye sufficiently to always make a good strong contact with the sender housing.  Hooked it all up and now I have an idiot light for the idiot. Hurray!  One quick question here.  Should I be concerned about the air that got into my fuel lines during installation of big line kit and senders? Does cycling my Raptor, turning the key on 5-10 times for a minute without starting the truck likely solve all air problems?  Or do I need to bleed the system?  If I need to bleed, how so?  Cracking my injectors?  I'm doing all this to protect my VP44 and would hate to screw it up now because air damaged the injection pump  Cracking the injectors would only remove air after the VP44.  Again should air be a concern  or can it safely be "flushed" through the system?  I have not thoroughly checked any leaking on my mods as I am waiting to possibly address the entrapped air consideration before I pressurize the system.

 

One last issue.  Since my truck has about 325K on it and I bought the truck at 200K,  I have no knowledge of the age, size or type of injectors it is currently running.  I do have the impression however that it has lost some power in the last year or so. (Other than loss of power my truck does seems to run/drive fine - no excessive blowby, oil burning, or smoke, etc.)  I am therefore considering putting some new aftermarket injectors on it.  I may also upgrade the turbo.  I'm not looking to make a drag queen  out of the truck, only giving it a bit more oomp on those long 5% grades while towing my 28' boat or 5th wheel.  I am leaning to putting +75 to +90 injectors on it.  Do any of you have any thoughts on my plans, and/or what sizes, brands, or types of injectors I should look for, or stay away from?  Similarly, is there any combination of injectors and turbo which you have had good luck with and think I should consider?  I did up grade my 47re to twin disk about 75K miles ago.  Finally, if I do go with a mild power upgrade as discussed,  do I need to add a transmission temperature gauge or other monitoring sensors?

 

Thanks again guys.

Thanks Mopar1973Man for your thoughts and advice.  Plan to do bleed as suggested before starting the motor.  Cycling Raptor without starting motor got my no running fuel pressure up to 18 PSI and thankfully the idiot light turned off.  Question for 015point9:  Why is 5 PSI alarm light worthless in your opinion?   I don't want to start an argument or rehash old posts, but EVERYTHING that I have read says that with the motor in stock configuration, the VP44 can run all day long without damage at 5 PSI.  Anything below this - a problem!  Several non Bosch companies I see have run tests to confirm this.  I understand that an alarm light at 10 PSI gives more margin for error.  However it is my plan to immediately pull over and shut down the engine anytime my 5 PSI alarm light turns on while driving.  At that point I will immediately look for the common low fuel pressure problems: a clogged filter; a failed lift pump, or a leak which developed somewhere in the fuel lines.

 

Last question.  Have any of you replaced the engine mount bushings on a 5.9.?  When I was working under the truck to replace the oil pan gasket I noticed that my bushings were in pretty bad shape (325K miles).  I understand that is best to do one side at a time and raise that side just enough to take pressure off the through bolt.  Remove the mount by removing the three bots which secure it to the block and loosening the through bolt.  On the driver's side it might be necessary to raise the engine further  or remove the starter to get clearance for through bolt to get by.  Plan to use Prothane bushings which I have already bought.  Any experience out there with these bushings or this job?  MY first reaction is that I am not sure how I am going to access all 3 bolts which secure the mount to the bock.  A couple look nearly inaccessible.  Any guidance would be appreciated.

[Mopar1973Man]

9 hours ago, Tbird9140 said:

Last question.  Have any of you replaced the engine mount bushings on a 5.9.?  When I was working under the truck to replace the oil pan gasket I noticed that my bushings were in pretty bad shape (325K miles). 

Keep your oil leaks to a minimum. Then keep all rubber clean of oil and fuel it will cause it to degrade faster. 431k miles and still got good engine mounts and the rubber is in good shape.

 

9 hours ago, Tbird9140 said:

Remove the mount by removing the three bots which secure it to the block and loosening the through bolt. 

I would figure that the engine just needs to be supported. If you remove the bolts from the bolt and the long bolt through the the mount it should lift out of the cradle its sitting in.

  

9 hours ago, Tbird9140 said:

Any experience out there with these bushings or this job?  MY first reaction is that I am not sure how I am going to access all 3 bolts which secure the mount to the bock.

Might need a long extension and wobble joint and impact gun and shoot most of them from the bottom. I know the driver side has quite a bit around it you could pull the ECM and fuel filter out and gain more room to getting the bolts out of the block. Starter is only 3 bolts and fairly easy to pull from under the truck. More or less remove what you need to gain working room and you should be able to get the mounts out. 

[LorenS]

18 hours ago, Tbird9140 said:

Plan to do bleed as suggested before starting the motor

If all you did was open up the fuel line, you shouldn't need to bleed the air. Just do the key bump and the lift pump will push the air out.

 

Once the VP44 starts trying to pump air down the injector lunes, THEN you need to crack the injector lunes and bleed.