High timing = sputter at certain rpm?

Smokin ACE

Smokin ACE

1st gen turbo tester
Joined
Aug 26, 2010
Messages
250
I've got my timing gear jumped a tooth and the pump is to the head, not sure how advanced I am degree wise, but the way it sounds it sounds like its up there, probably be 25-28*, maybe more, not real sure. But what happens with this is when I am driving and get into 3rd or OD and hit about 2200-2500rpms the truck sputters and coughs a little bit until I either drop my rpms back down a bit or go past that rpm range. It seems like it does this sputter when the turbo starts to really light and come on hard. Once I go past that rpm range it comes to life and really screams but in that rpm range it will do this? I've had it like this all summer since I put my 14mm VE on last spring. Its ran strong with this timing setup once you give it all the beans, especially truck pullin this year. I know if I back my pump off back to factory or below factory marks it won't have this sputter issue anymore, even still jumped a tooth.

Right now my setup is a 14mm VE cranked up, 6x18 injectors (155* spray angle) and a 66/71/14 for air. Even with my old 12mm VE and POD injectors, it would do the same sputter if I had the pump above the factory marks at all with it jumped a tooth. I've just been curious as to what causes this or what is happening? I've thought maybe the injectors spraying outside the piston bowl, but it screams once I go past that rpm spot so I kind of scratched that theory... I heard once it was too much fuel for not enough air at that certain period of time until my turbo would light? I've just always wondered about this and if anyone else has had this experience?
 
I had the same thing happen with stock delivery valves and big injectors on my 95 Dodge p-pumper. Different pump but same theory, lots of timing, and big injectors.....and mine did the same thing until we switched delivery valves to ones that provided more fuel. My theory is that that much timing makes the fuel curve a little wacky at anything other than full tilt. I've seen diesel pulling tractors even throw flames while warming up, so once you have the fuel and timing curve set for WOT, at other times it can get a little wonky. I wouldn't really worry about it. Not sure what causes it either.
 
Fuel splitting the piston bowl lip, has nothing to do with the delivery valve. I always recommend getting the pattern in the bowl or out of the bowl, spraying on the lip is what causes the bowl lip to roll/melt.
 
Mine does the same thing, sputters right before the turbo lights. I thought it was just because it was giving too much fuel sort of putting the fire out.

It seems to do it a lot less since I got the spool flange on.
 
Granted, I don't have the amount of fuel a 14mm pump can provide but with my 12mm flowing 263cc's at 2,000RPM and base timing/piston travel from 1.3mm at TDC (I need to verify that) to almost 10mm of advance piston travel and the 5x.013s (68-70lpm) injectors, I don't get any kind of sputtering through any of the RPM range. I, also, don't know exactly what kind of timing advance that equates to in degrees. I do know that the stock setting of 1.25mm is about 12.5degs.
 
Mine does the same thing with the timing jumped a tooth, and with the 6x16 injectors. I posted about it too. And didn't get many responses. Jqmile chimed in and another as well said something about a governor sticking. Smokems explanations makes sense to me too, and I grasp it. Mine did this before I skipped the tooth. But now that I've advanced my timing, It starts the sputter a little sooner. Which makes it a pain to drive at highway speed, cruising. Now if I mash it, and bring the boost up, the truck runs smooth and hard. I'm now a little concerned, now that I've read smokems response. Or maybe I'm being a sissy.

Eric
 
Sutter1stgen said:
Mine does the same thing with the timing jumped a tooth, and with the 6x16 injectors. I posted about it too. And didn't get many responses. Jqmile chimed in and another as well said something about a governor sticking. Smokems explanations makes sense to me too, and I grasp it. Mine did this before I skipped the tooth. But now that I've advanced my timing, It starts the sputter a little sooner. Which makes it a pain to drive at highway speed, cruising. Now if I mash it, and bring the boost up, the truck runs smooth and hard. I'm now a little concerned, now that I've read smokems response. Or maybe I'm being a sissy.

Eric
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YES YOU ARE BEING A SISSY.:shake:
 
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