put on your thinking caps 4 this one,pump guys

[hillfolk'r]

ok,84td w/ garret,and 12mm pump head on stock pump,,problem: if i wind out a gear,like 3rd or 4th,and push in the clutch,throw it in neutral,,as the revs drop,itll stall out!!!!now,i have been  driving it  a while b4 i noticed this,,and i have played w/my idle,cause i didnt want the "runaway" feeling ,,iwonder if its this,,or a pumpproblem,,because if you let it stall,,you can crack the lines loose+freakin pray itll reprime,,i remember some pumpguy sayin,to disconnect power to pump sol+crank it over,it wont need primed,,,,ive been told it could be a control/housing pressure thing,,or idle set too low thing,,,,,if you keep banging gears itll rungreat!! any ideas???

[QuickTD]

Let me get this straight, it requires bleeding/repriming to get it started again after it stalls? If so I'd suspect a supply problem, bad tranfer pump? You're trying to feed a big 12mm appetite, maybe an electric transfer pump would help. You might try drilling and tapping the head of and "OUT" bolt so you can put a housing pressure guage on it and see whats going on. You should see 90-100psi at full honk.

[fatmobile]

If you have to reprime it then it must be running out of fuel.
 How's your fuel filter?
 Put a vacuum gauge on the fuel line and see how hard it is pulling to get fuel while you are "winding it out".
 If it's pulling hard, any dissolved air in the fuel will expand under the vacuum and turn into large air bubbles that enter the pump and starve it of fuel.
 Got any clear fuel lines into or out of the injection pump?

[hillfolk'r]

its not a supply issue,,imusing a lift pump,,got 15 psi@ pumpinlet,,new filter etc,,its not a supply issue,, yea ihave to reprime it if i let it die right out,,if ilet clutchout,,itllcatch again,,keep runnin,,,keeps pissin me off,cause ipulled outta somewhere one day,got on it hard in 2nd,,lost traction,but had to stopfor a light that was changing,freakin died out,almost killed the battery repriming it(lines loose,and yea lift pump runs keyon),,,,a pump place italked to,said it could be a linkage problem in the pump,and ishouldnt have to "prime"it,,it canbe un stuck by cranking it w/the stopsolenoid disconnected,or somethin,,,,,,,,anyone mess with dodges?? ive seenthe inline pumps dothis sometimes,with an auto trans,do a brake stand,,dont fry em,jus get it spoolin,then let off the gas+itll stallout,,seen this a few times at work,,,but thats a inline pump,different  deal,,,,,,,,,,i wonder if its from idle too low,sittin there it doesnt sound too low(i have a vdo dieseltach,i set it against the pulse timer at work),ireads like 800at idle,id have to verify with timer  though,,,,

[vwmike]

What if you up the residual fuel quantity?

[Patrick]

Sure sounds like an air leak somewhere. Had a similar problem a lot of years ago with a PT pump on a big cummins. Got to know when it was time for a new seal on the throttle shaft by the way the truck ran.

I think it's sucking air somewhere.....  
Maybe where the oversize head is bolted on?

[QuickTD]

When you back off the loud pedal at high speed the governor flyweights will push the linkage back to zero fuel pretty hard, maybe its jamming and the cranking just frees it up gain? Have you messed with the governor at all? It does kind of sound like the governor linkage gets "stuck" somewhere below idle speed. Holding the pedal to the floor while cranking should "unstick" it though, without the need to reprime. Of course, if you've eliminated any governor springs the linkage pretty much HAS to move when you step on the pedal.

[hillfolk'r]

What if you up the residual fuel quantity?

ya mean turn up the idle speed?,its an 84 pump,,,,not a2 style,with all that idle speed lingage crap,,,,,,its not a  suction leak either,,,,,,,,,,governor all is stock,,its just a 84 pump w/12mm head,,,,,i did lower the idle speed to be sure  it would idle down,,,,,,,,will my idle speed bein too low cause this problem??cause iknow if its set too fast,it wont idle down,thats "normal" for any pump,,is too slow possibly causing my problem,??

[dieselweasel]

What is your idle speed?

[andy2]

I'm no pump expert and this is probably proof of it.Anyways when you turn down the idle doesn't it decrease the idle spring's tension, therefore making the idle sensitive.So if you back off the fuel quickly the governor cuts off the fuel a little much below idle due to the lower spring tension causing the engine to stall.I've been through somewhat  similar issues with my modded pump and I ended up having to raise the idle(spring tension) higher than I wanted the engine to idle at in order to have a stable and reliable idle.

Just my 2 cents :wink:I'm probably out to lunch anyways :lol:

[hillfolk'r]

from my ownexperience(and now since ive learned alot at work from one of thepump guys that will talk),,if you take a stockpump,and  crankup the  max fuels crew it will get that "slow return to idle from hi rpms",so you have to turn idle down,,if you turn in fuel screw,idle goes up slightly,anyways,,i turned it down,and then some,,,,,,it  could be around 700-800,,,i dont trust the tachfor setting idle,,,i did set max speed (calibrated tach)though,,that was fun,,ithrow a brickonthe throttle ,making sure ihad 5200,,,most of theguys in the shop,theyare used to truckengines ,like 2100is singing,,,

[fspGTD]

hillfolk'r - you ever get your stalling 12mm pump problem straightened out?

[hillfolk'r]

hillfolk'r - you ever get your stalling 12mm pump problem straightened out?

,,,yea its runnin good,,,basically it was because of idle set too low,,,,now imusing this pump on my tdi,,and ihave the idle higher,,its oknow,,,,,,,,,,,ive noticed 2 things(or more),,if u turn upmax fuel,,you will have to turn down the idle,, from hi revs itll "hang",,,,,if idle set too low,,itllcut out ,,,theres a sweet spot,,,and its not that narrow,,but iwas at the low end,,,thanks yall