Mopar1973Man's Dodge Cummins Diesel Forum - 12 Valve Powertrain Related

Technical article on the Cummins lift pump. Free to Cummins 12V owners.

cumminsfuelsystem — Mon, 30 Aug 2010 22:55:22 GMT

Hi

We have been working on the Cummins 12v fuel system and lift pump for over 14 months. We uncovered a lot of data, from hundreds of tests. This is article number one in a six part series. I hope you like it.

Rob Parelli

Here is the link

http://torkteknology.com/news.php?newsid=5

12V IAT Readings

ISX — Sat, 21 Aug 2010 19:42:06 GMT

Everyone seems to know the IAT of a 24V, but I never see anything on a 12V. So I cut the IAT wires, soldered wires to them, ran them into the cab, crimped them onto my multimeter leads, and I was able to read Ohms while driving. I am still working on a calculator to see what temps I am seeing but so far here is what I have personally tested, I just need a way to connect the dots for the calc.

I made a video of the test run. Engine wasn't started so I knew that 77F must have been 10kOhm.

One thing to note is that the computer was smart enough to know it had no continuity in the IAT wire and the WTS light blinked the entire time the key was on.

You can see that EGT and IAT have no relationship. You can see that air being compressed (BOOST) is what drives the temp up. At then end of the video there is a short clip of me idling after the run. The IAT is going up steadily because the turbo is hardly pushing any air. This allows the air in the intake to slowly swirl around and pick up heat from the engine itself, causing the air to heat up.

If you look at the table, you see that 116.5F is 4.1kOhms, so I wasn't getting anywhere near it.

Remember, lower resistance means HOTTER temps!

--- Update to the previous post...

Alright I got everything to temps x5 so I got results from 70-100 in the table now. PITA but I wanted to see exactly where it was. From what I can tell, I maxed out around 95 or so. That was almost to the floor when it got there, but only 18F over ambient. I was up to temp by that time but I still want to see what I get on an actual trip that takes longer than 3 minutes, when everything in the engine bay has got to whatever temp it wants to be at.

12V Codes

idahocountryboy — Fri, 20 Aug 2010 15:52:36 GMT

I have a buddy with a '97, NO power to his guages or dash, radio, or cam. Runs fine but... ? He pulled the codes this is what he got.

9141
Keyword 2000
J1850VPW

Any help? Is there a way to find the codes means? thanks.

1997 Dodge Cummins - Full color wiring diagrams

Mopar1973Man — Thu, 19 Aug 2010 21:16:31 GMT

Hey Gang...

I got the 1997 Dodge Cummins full color wiring diargram finally compiled for you guys and gals.

http://forum.mopar1973man.com/downlo...do=file&id=129

Enjoy...:thumbup2:

How the P7100 works

ISX — Tue, 10 Aug 2010 12:06:31 GMT

Just found this pdf which is very very detailed. http://transportation.centennialcoll...203/inline.pdf

An interesting part is towards the bottom they talk about a PE7100. This is a P7100 that is computer controlled with dynamic timing. I can hardly find any info on this so it must have only been used on one application. I guess they used it on VMAC-I engines--Mack trucks.