1947 KB3 2016 GMC 3500 chassis

[M4wdFab]

plated and inspected today.  drives good!  front end looks like she needs some alignment adjustment with a little too much stance

[M4wdFab]

took about 15min into an extended drive tonight to pop a 30amp fues that was feeding the relay for electric rad fan and fuel pump.  i have done this the same way on 15 trucks and never had a fuel pump that draws 16amps lol 


coasted over to the side of the road about 9pm tonight on jefferson rd clay?   

found a melted fuse, warm wires.  got stuff bipassed in about 10 minutes with some trash i found on the ground (had zero tools or materials)

made it to autozone and bought some stuff.  bettered my fix and made it home. 


added a 3rd relay, separated out the fuel pump on its own. 

packed a little roadside bag.  need to start throwing fire ext in rigs too. 

[etk300ex]

16 amps?


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[M4wdFab]

yes fuel pump draws 16 amps

fan draws 15 amps.

too much for 30amp circuit after warm wires

[gif]

truck looks great in person.  nice BIG flat bed. 

[M4wdFab]

first GM i have touched the front a arm alignment bolts/bushings wernt F'd.  both sides cranked to get rid of the large amount of negative camber, it almost looks ok now! 

[M4wdFab]

good drive out to log cabin and back.  solid unit.  needs heat for nights like tonight!

[M4wdFab]

not sure what happend but left lights on while fueling and then smelled sulfer and wouldnt start after fuel.  was kinda blocking exit to fuel station so had to hussel and stick a different battery in and get it moved to parking to further diagnose. 

I think the battery just plain gave up and this engine/setup wont run with out a battery connected to it (even with 14.2v on the leads)

swapped and zip tied a wrong size battery under the hood from the bucket van and drove 15min back home without issue.

[mr.mindless]

sulfur smell makes me think overchange at first thought

[M4wdFab]

fresh battery installed
replaced electric cooling fan and changed to front pusher


first fan was blowing 30amp fuses and sounded weird.  bench tested bad sounds and pulling 27amps at 9v on my big charger set to 40amps
new same fan pulls 9amps @ 12v

[M4wdFab]

felt like it lost 4 cylinders on the way to Toms with the bucket truck this week in tow.

in N no load revs up great, in drive or reverse, refuses to give more that 15-20% throttle from a brake stand or normal start out.  20-30mph it comes back but still runs rough.


scanner shows no PCM or transmission codes relevent other than failed MAP sensor, and zero MAP data.

runs same with MAP plugged in or out.  (scanner plot shows no MAP output, but it does show calculated MAP)

i guess 40$ to amazon is easier than research and wire chase first.  bah. 

[M4wdFab]

well, 90$ maf local no change.   data still says zero maf, dont know why.  does have a calculated maf shown.  john said it should switch to speed density and be fine anyway unpluged, no change. 


kinda feel like i want to check fuel pressure and throw a set of plugs at it.  just feels sluggish and pulsating under 3000rpm.

stumped one why it was just a step change in performance.   

[mr.mindless]

I'll say out loud here that maybe it sees brake acuation signal and is eating throttle input to prevent Toyota problems.

I don't know if GM computers do that, but I know VW always has. If you're on the accelerator and the brakes, you have to do some special something to get any acceleration. I think let all the way off and stomp on it maybe more than once.

It's a weird one for sure. And totally worth checking fuel pressure for sanity

[M4wdFab]

i guess when plugs are completly shot you still will never get a misfire code or misfire event logged.  its just pulls fuel based on 02 feed back to not kill it self? weird


i had ordered plugs for it with a rear wheel seal.

pulled pluggs.  second from top only one that had some what of an electrode left, the rest completely hosed, way out of spec, probably 0.200 gap or more (.040 spec)

changed plugs and wheel seal on lift today (both rear wheel bearings had 1/4" play in hub preload)

power / stumble problem gone on test drive. 


finally a win! 

fixed tail pipe angle that got welded on angled up. 

[mr.mindless]

Amazing it was running at all with those plugs! wow

I threw plugs at the Z3 in hopes of smoothing out a rough idle, made zero difference. plugs I pulled were BMW branded at almost 130k and they looked excellent. Those almost have to be original plugs don't they