12 Valve only start with throttle, thick smoke

T

texastruck

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Apr 12, 2017
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I pulled the 12v from a 1994 Dodge 2500. I started it up on the garage floor and it ran fine. Since then, I’ve done the following mods:

5x0.014 injectors
Advance timing to 19*
4K GSK
60# Valve springs
KDP fix

I just tried starting the engine again after finishing all the above mods, and it wouldn’t start, even after priming and cranking several times. When I gave it the slightest throttle, it starts, but will die once I let go of the throttle. Also, once it does fires off, it makes a TON of thick black smoke immediately. I haven’t been brave enough to hold the throttle for more than a second or two.

My first thought was that the engine was being fed too much fuel because of the larger injectors. I hadn’t made any adjustment to the AFC/smoke screw/star wheel when I did the mods, so today I turned the smoke screw Out and the star wheel back to the middle of its travel (it had been almost fully forward) hoping to reduce the smoke. I tried starting again, but no difference at all. Still won’t start unless I hold the throttle, giving off a big cloud of black smoke, then dying.

What more should I be looking at to fix this? I know the 5x14 injectors are a bit larger than stock, so controlling the smoke may be a challenge, but I feel that it should at least stay running.
 
I’ll check the GSK in the morning. I’ll try to google the symptoms of an improper set up in the meantime. Not sure if I would need to screw the retainer ring inward, or outward.

I came across a post where someone did not tighten the retainer ring enough, and he ended up jamming and bending the threaded stud when he when to start it. He had to pull the p-pump off and get it serviced. Cost him $750. Ouch.
 
Check your timing .. did you clean the gear and pump
Shaft and torque it properly? What method of timing advancement did u use
 
Yes I was sure to clean the shaft with brakleen to remove any oil or contaminants. Of course I suppose a timing slip could always still be possible. I used a timing wheel on the harmonic balancer to set my timing.
 
Well I went out to adjust my idle, still wasn’t starting, even when applying throttle. I kept priming the lift pump, thinking maybe the fuel had drained out overnight. Didn’t really seem like any fuel was being sucked out of the gas can though. Took the hose out of the gas can and covered the end of the hose with my thumb while priming. No vacuum. It was lifting fuel just fine yesterday, I had done the same “thumb test”. What the hell is going on now? Trying to solve one problem, and more keep popping up.
 
Took the lift pump off, put it on my bench, hand primed it again with my finger over the inlet, nothing. Primed again but this time pressing the the cam plunger instead, and it worked. Tried the hand primer bulb again, and now that’s working again too.... ?? Glad it seems to be working again, but geez. Guess I’ll reinstall it and try to solve my original idling problem
 
Are you sure the timing was advanced? More than one guy has inadvertently retarded the timing.
 
I’ve thought about that too. I remember I took photos of when I was doing the timing. I’ll go back and see if I may have turned the engine over the wrong way when trying to advance my timing
 
Yes, stock was 12.5*


I’m still having issues with my lift pump. Just ordered a new one, should get here Wednesday. I’ll move on to other things like A/C and alternator brackets til it arrives.
 
Alright I installed a new lift pump tonight, verified it was working, and attempted to start the engine. It fired right up! Then the revs started climbing. I flipped down the FSS lever, but I didn’t shut down the engine. Still revving high. It was running away. Luckily I had placed a board next to me for this exact scenario. I choked off the intake and killed the engine. The whole process from startup to choking it off took no more than 3 seconds. Felt like eternity though.

What should I be looking at to fix this? After the runaway I unscrewed the smoke screw a full 3 turns and adjusted the idle bolt by the throttle linkage. The star wheel i left alone since I had already moved it from fully forward to slightly before the middle (closer to the firewall side of middle).

I posted on 4btswaps and someone replied I may have installed the governor spring kit incorrectly, specifically by possibly removing the shims under the factory idle springs that go back in the pump when installing a GSK. He said only a certified Bosch technician with a pump stand can fix that mistake. Is that true? I haven’t read that anywhere before.
 
I found some pictures of when I removed the old spring during the GSK installation I did. Sorry for the poor photo quality. Below is everything I removed from each side of the governor.

Untitled by Ivan Alvarez, on Flickr

Untitled by Ivan Alvarez, on Flickr


And below is a photo I took today of the remaining items I saved in a ziploc bag. Whatever you don't see in the photo below, went back into the governor housing with the Pacbrake GSK

Untitled by Ivan Alvarez, on Flickr
 
texastruck said:
someone replied I may have installed the governor spring kit incorrectly, specifically by possibly removing the shims under the factory idle springs that go back in the pump when installing a GSK. He said only a certified Bosch technician with a pump stand can fix that mistake. Is that true? I haven’t read that anywhere before.
Click to expand...


Sounds like gov springs to me, whose gov springs did you use?what pump is on the motor? Ive had the same issue with a 190 pump on a 24valve. Make sure you removed all of the shims, make sure you didnt remove the biggest gov spring(ive seen people do it)

Back them all the way off and run it back down until you get 2 solid clicks out of it, test it and start going one click at a time until it seems right. Ive had cheap gov springs not want to idle and have swapped them out for a nicer set and worked just fine.



Sent from my iPhone using Tapatalk
 
Downtownbrown said:
Sounds like gov springs to me, whose gov springs did you use?what pump is on the motor? Ive had the same issue with a 190 pump on a 24valve. Make sure you removed all of the shims, make sure you didnt remove the biggest gov spring(ive seen people do it)

Back them all the way off and run it back down until you get 2 solid clicks out of it, test it and start going one click at a time until it seems right. Ive had cheap gov springs not want to idle and have swapped them out for a nicer set and worked just fine.



Sent from my iPhone using Tapatalk
Click to expand...

I used Pacbrake's spring kit.

I'm going to open up the governor up and check it out before I try firing it up again. Thank you
 
I loosened up the governor springs by 2 clicks on each side. Fixed the problem. Thank you everyone who replied and thank you Downtownbrown for sharing with me some tips from when he had a similar issue.

Moving on to installing the transmission now
 
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