Ecm delete possible?

[35hunnit]

Finally picked up another project. Someone else's half done Cummins swap into a 96 k3500, originally a 5 speed 6.5, now a 12 valve 5 speed. The fabrication/mechanical part is easy, my main question is if the ecm can be deleted or if it's crucial to gauge functionality on these trucks. On my squarebodies I've thrown the tbi ecms right in the trash and wired the gauges independently no problem, but I know these trucks are slightly more computer involved. I've searched around but I can't find an answer on if it's can be pulled or not

 

[kennythewelder]

The ECM controls, fuel, spark, the gauges in the dash, and shifting of the trans, on automatic transmissions. To delete it, you have to replace the intake, the distributor, figure out the gauge wiring, and in auto trans models, you need to swap the trans for a non computer controlled one, or, get a stand alone ECM for that to or, have yours programmed just for the trans.

 

[35hunnit]

Fuel, spark, and transmission are all non issues. As I said, Cummins with a 5 speed. My only concern is gauge cluster functionality, I was hoping the whole dash wasn't computer controlled and each gauge was just wired individually to a sensor like the 80s trucks

 

[kennythewelder]

Well,,,, it kind of is like the older trucks, except for the speedo. Trouble is, you have to find the ground wires for all of the gauges. It think once you eliminate the ECM wiring, you eliminate the grounds with the wires. they are all in the same harness,from what I have researched. I wanted to carb my 97 Vortec, until I saw how much of a PITA it is to to that. I have a 4L60E trans.

 

[35hunnit]

If the speedo is the only issue that ain't nothin an order from Dakota digital can't fix. I can't find a single thread on any forum of someone that's deleted the ECU on a late 90s truck, so I guess I'll look into the wiring when I get home and start up thread on the process

 

[kennythewelder]

Back when, I had found some videos on YouTube, of people who did the delete on the 5.7L Vortecs.

 

[OutlawDrifter]

You should be fine on the '96 era stuff. Just get a pinout for the firewall connectors so you can retain the wires you need. You can probably adapt the OEM coolant temp/oil pressure senders to the cummins block so they match your gauges.

98+ stuff uses the ECM for the fuel gauge, so you're good there too with the '96 model year.

There are a couple of cummins swaps on here, "The Black Fox" was one of them after it was sold to a new owner, but it is a newer 98+ pickup.

 

[35hunnit]

Sounds like I lucked out then. I intended to adapt the gm sensors to the Cummins block, and I believe the truck still has the stock tcase so the vss should also be factory functional. Tach will be the only thing, but being a factory 6.5 it pulled tach signal from the alternator right? Should be able to just reuse that system

 

[Frank Enstein]

You may need one of these to recalibrate the tach.

Dakota Digital SGI-100BT Dakota Digital Universal Speedometer and Tachometer Interfaces | Summit Racing

Free Shipping - Dakota Digital Universal Speedometer and Tachometer Interfaces with qualifying orders of $109. Shop Gauge Sending Units at Summit Racing.

www.summitracing.com

 

[CumminsBronco]

Finally picked up another project. Someone else's half done Cummins swap into a 96 k3500, originally a 5 speed 6.5, now a 12 valve 5 speed. The fabrication/mechanical part is easy, my main question is if the ecm can be deleted or if it's crucial to gauge functionality on these trucks. On my squarebodies I've thrown the tbi ecms right in the trash and wired the gauges independently no problem, but I know these trucks are slightly more computer involved. I've searched around but I can't find an answer on if it's can be pulled or not

I have about 400 miles on my 97 Suburban with Cummins 5.9. It's my 2nd swapping, the first being another 97. I've stripped the ecm down to 23 pins being used. The ecm was originally 120 pins with some not having been used. I'm sure you could strip all of it out, as my son did on his 93 S10 5.9 swap.
I wanted to keep some functions though that need the ecm. Cruise control, speed sensitive steering, IP panel...gauges
I did unknowingly strip out the crank position sensor and that left me with non-functioning AC. I considered rewiring that back in but opted to rewire the AC circuitry to not use the ecm for AC control.
If you decide to keep the ecm for some of the luxuries I'll guide you with any help I can.