cummins n 14 conversion

Truck Shop

Well-known member
No---------But the first N14's were mechanical in 1992 and early 93 from then on N14's were total electronic. The first mechanical N14's had a fuel system called STC-Step Time Control.
But those engines used the mechanical PT injection pump with oil pressure advance/retard injectors. The early mechanical N14 is a very good engine and can be boosted to 550 plus HP.
Stock ratings were 370 to 435 HP and those engines are not easily found these days. But they can be had also.

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rzucker

Well-known member
No---------But the first N14's were mechanical in 1992 and early 93 from then on N14's were total electronic. The first mechanical N14's had a fuel system called STC-Step Time Control.
But those engines used the mechanical PT injection pump with oil pressure advance/retard injectors. The early mechanical N14 is a very good engine and can be boosted to 550 plus HP.
Stock ratings were 370 to 435 HP and those engines are not easily found these days. But they can be had also.

Truck Shop
Yep, I think a retrofit on an N-14 would cost some serious coin to be done right. Not saying it cant be done.
 

farmboy

Member
please give some detail? is it not basically the same block? my reasoning is my n14 has not run in years and would take some serious cash to be returned to electronic control.
 
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rzucker

Well-known member
Personally, I think you would be money ahead to trade out for a Big Cam 4 mechanical engine. To convert the N-14 you would be looking at injectors and a PT pump correctly set for your application. I don't know if you would need to change the cam and cam timing. It's an interesting concept. Oh, if your tach and speedo run through the ECM those will need to be rewired and recalibrated and cruise control will be out.

What's the issue with your N-14?
 
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Truck Shop

Well-known member
Plus throttle pedal and linkage. When I say no it's to discourage these kind swaps. Yes it can be done.. What is missing from your N14?
If you swap out to older big cam mechanical you can use the N14 intake and keep the air to air. Look for a tired mechanical N14 for the parts to swap out.
Here is a used running mechanical for $4000.00, that's about right on price. Reman would be around 18,000.00. By the time you find what you will need for
your engine you will have some serious cash involved.

https://www.rockanddirt.com/attachments-for-sale/CUMMINS/N14/invnum=6013849

Truck Shop
 
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farmboy

Member
it used to be my daily driver, I retired it but would occasionally start it, last time it ran it started missing but cleaned up with some throttle, I assumed it was fuel going bad.(fuel was bad) eventually I pulled injectors and had a friend of mine rework them (he has an injection service shop) still wont run. so finally I decided to send computer off for testing but the wiring into computer wont unplug (its like the terminals are bonded to each other) so basically now it needs a computer and two harnesses and possibly even a set of injectors. all for something I would just like to hear run again. ps I have a pt pump and a set of injectors from a bc3 400.
 
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Truck Shop

Well-known member
The main Injector harness is $845.00 from Cummins, If I remember right there is a screw that holds the connection plugs into the ECM.
I have a friend that just replaced his harness last week, I will check with him.
 

rzucker

Well-known member
it used to be my daily driver, I retired it but would occasionally start it, last time it ran it started missing but cleaned up with some throttle, I assumed it was fuel going bad.(fuel was bad) eventually I pulled injectors and had a friend of mine rework them (he has an injection service shop) still wont run. so finally I decided to send computer off for testing but the wiring into computer wont unplug (its like the terminals are bonded to each other) so basically now it needs a computer and two harnesses and possibly even a set of injectors. all for something I would just like to hear run again. ps I have a pt pump and a set of injectors from a bc3 400.
Ok this has been sitting awhile... Have you checked the ECM feeds at the batteries for corrosion? have you checked the ECM fuses? Truck make and year would be really helpful here. If it ran when parked I think its something stupid simple. Seen several "no starts" over a corroded fuse holder. That one should have 2 hot feeds from the batteries with a fuse in the positive leads, those will be 10 ga. wires. follow them to the ECM looking for the fuses. Frieghtliner usually hid them behind the battery box, Kenworth liked to hide them on top of the transmission or in the battery box. Don't forget to clean the grounds too. Also tug the leads at the battery ends, they can corrode away there too.
 

Truck Shop

Well-known member
I will agree with part of that RZ but the N14 ECM's I have worked on mainly have 14 gauge wire in and out. Before any thing is done check with a test light for power at the ECM. I ran though testing one
of these about a year ago. I will try to find the numbered pins on the ECM that should have power with key on. But I feel the culprit is the cam/crank position sensor behind and above the oil pump.
Those are notorious for going bad at the drop of a hat, for no reason.

Truck Shop
 

Truck Shop

Well-known member
And those connections at The ECM should be tight and not easy to unplug. If those were easy to remove then I would definitely expect corrosion on the terminals. This is a good thread

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rzucker

Well-known member
I will agree with part of that RZ but the N14 ECM's I have worked on mainly have 14 gauge wire in and out. Before any thing is done check with a test light for power at the ECM. I ran though testing one
of these about a year ago. I will try to find the numbered pins on the ECM that should have power with key on. But I feel the culprit is the cam/crank position sensor behind and above the oil pump.
Those are notorious for going bad at the drop of a hat, for no reason.

Truck Shop
I may have been thinking Cat with the 12-10 gauge wire, same idea. One quick test I used on an M-11 was to connect 12 volts to the shutdown solenoid with a gator clip, it fired right up. That's when I found the bad fuse holder in the ECM feed.
 

farmboy

Member
1996 intertrashional 9300, brand new cam sensor (tach worked for one crank then no more) ecm impossible to unplug. no fuel,,,,, will start on either then promptly die.
 
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farmboy

Member
when I first started working on this pos I checked the injector wiring with noid lamps, they do flash but not real brightly, I have tried a hot wire to shutoff solenoid, all electric connections that I can find have been cleaned as well as all the grounds, yesterday I noticed the tach did not work so I installed a new cam sensor (genuine cummins) and tach worked for one try then not any more. its a nightmare that I cant wake up from.
 

farmboy

Member
battery cables run to starter all internal feed is from starter solenoid terminal. everything in cab works correctly.(lights fan etc)
 

Truck Shop

Well-known member
Pins to check are at Connector C at the ECM #23 and #22 plus pins #21 and #20. Recheck the connector at the cam sensor if its real oily clean it with break clean and use a small brass brush to clean pins and connections.
and spread some dielectric grease on the connectors. Pins 23 and 22 are unswitched constant power and those are direct battery power. Pins 21 and 20 are unswitched power also but some times depending on engine those
are not always used.

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rzucker

Well-known member
Is this thing pumping fuel? Take the line loose at the top of the shutdown solenoid and crank it. It's not always electronic issues.
 
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