June 24, 2018, 10:55:20 AM

Author Topic: 8v92T  (Read 16061 times)

Offline Nineforever

  • Nineforever
  • Full Member
  • ***
  • Posts: 142
  • 100 klms south of Yellowknife NWT Canada
8v92T
« on: March 14, 2014, 07:54:35 AM »
Good Morning having troubles with my 8v92T   Engine starts and runs smooth until you put your foot into it after 1500 RPM ,,, feels like its starving for Fuel or Air .
Ive changed the Air Filter and changed the fuel filters ,,, also ive primed the system by using a hand pump but cant seem to keep the engine running .
Any thoughts on this ..... im thinking the fuel pump is weak ... witch would explain it bagging out after 1500 RPM when it was running prior to me changing the filters .
Is the fuel pump on a 871 the same as a 892 .... they look the same .
Dave
Hyway 3 100 klms south of Yellowknife NWT Canada

Online luvrbus

  • Hero Member
  • *****
  • Posts: 19434
Re: 8v92T
« Reply #1 on: March 14, 2014, 09:01:15 AM »
Install a gauge in the top of the secondary filter and check the pressure you should have 65 lbs it may be the yoke rounded off slipping,I replace those pumps with the DDEC high volume pump a better pump IMO if it runs at 1500 rpm I doubt it is the fuel pump fwiw
« Last Edit: March 14, 2014, 09:28:12 AM by luvrbus »
Life is short drink the good wine first

Offline Utahclaimjumper

  • Hero Member
  • *****
  • Posts: 1261
Re: 8v92T
« Reply #2 on: March 14, 2014, 09:36:00 AM »
 You haven't indicated what vehicle this engine is installed in,,if a bus, most are 40- 50 years old so pressure check the fuel line from the tank, most are metal and corroding from inside out.. >>>Dan
Utclmjmpr 
 EX 4106 (presently SOB)
Cedar City, Ut.
 72 VW Baja towed

Offline Nineforever

  • Nineforever
  • Full Member
  • ***
  • Posts: 142
  • 100 klms south of Yellowknife NWT Canada
Re: 8v92T
« Reply #3 on: March 14, 2014, 11:07:36 AM »
LuvrBus witch yoke are you refering to
Thanks Dave
Hyway 3 100 klms south of Yellowknife NWT Canada

Offline Nineforever

  • Nineforever
  • Full Member
  • ***
  • Posts: 142
  • 100 klms south of Yellowknife NWT Canada
Re: 8v92T
« Reply #4 on: March 14, 2014, 11:12:23 AM »
Hi Claim Jumper
The 8V92T is a low klm instaled in a 92 MCI 102c
Hyway 3 100 klms south of Yellowknife NWT Canada

Online luvrbus

  • Hero Member
  • *****
  • Posts: 19434
Re: 8v92T
« Reply #5 on: March 14, 2014, 11:33:10 AM »
Dave,there is a yoke that drives the fuel pump off the blower remove the pump and you will see the yoke they are bad about the square shaft on the pump rounding the hole in the yoke I always replace the yoke when replacing the pump fwiw
Life is short drink the good wine first

Offline TomC

  • Hero Member
  • *****
  • Posts: 8644
Re: 8v92T
« Reply #6 on: March 14, 2014, 11:53:21 AM »
Could be a baffle in the muffler blocking the flow. Might take off the muffler for a run if you can't find anything else out. Besides-it just sounds cool with a straight pipe. Good Luck, TomC
Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline akroyaleagle

  • Hero Member
  • *****
  • Posts: 624
Re: 8v92T
« Reply #7 on: March 14, 2014, 02:57:47 PM »
Any chance a fuel line is collapsing? Are the fuel filters full after you drive it?

When you "floor" it, does it smoke? White or black?

Is the turbo plumbing leaking? Is there a whistling noise going down the road?
Might need a helper in the bedroom for that one. Get one with good hearing, most of us are half deaf.

Is the throttle cable stuck? Check to see if the fuel arm is moving through all of it's travel.

If none of these or the other suggestions you have received help, let us know.
There is a vast amount of knowledge on this board.

Joe Laird
'78 Eagle
Sioux Falls, South Dakota

Offline Nineforever

  • Nineforever
  • Full Member
  • ***
  • Posts: 142
  • 100 klms south of Yellowknife NWT Canada
Re: 8v92T
« Reply #8 on: March 14, 2014, 09:41:15 PM »
Was able to get the engine running again and stay running , i went threw the priming process a zillion times with no luck it would suck the filters dry and the engine would quit . I called the local fuel truck operator got him over and we filled the fuel tank to the rim it took 176 littres then went threw the process again ... filled the primary and secondary filters. Then  using a bulb primer with hose into the top of the fuel filter bracket i pumped best part of a 5 gallon jerry can into the system then stuck the hose into a full 5 gallon jerry can .... then started the engine it sucked the 5 gallon jerry can close to the bottom i shut the engine down replaced the bleeder screw where i had the the hose contected ... started it up its running again .

The problem of it bagging out after 1500 RPM still there ..... but adleast i know its not the filters ill check out the yoke on the fuel pump tommorow
Thank you every one all keep you posted .
Dave
Hyway 3 100 klms south of Yellowknife NWT Canada

Offline Nineforever

  • Nineforever
  • Full Member
  • ***
  • Posts: 142
  • 100 klms south of Yellowknife NWT Canada
Re: 8v92T
« Reply #9 on: March 14, 2014, 09:58:16 PM »
Akroyaleagle  the filters are full after taking it for a good run .... the engine runs nice and clean as it always has no smoke ... ill check the throtle tommorow and look for a collapsed fuel line
Tomc all also check the exhaust
Thanks every one all keep you posted
Hyway 3 100 klms south of Yellowknife NWT Canada

Offline akroyaleagle

  • Hero Member
  • *****
  • Posts: 624
Re: 8v92T
« Reply #10 on: March 15, 2014, 07:39:19 AM »
176L = 46 gal of fuel. Low fuel wasn't the problem.

If it is sucking the filters dry, it probabably is not the fuel pump.

To check it would require the engine to be over 1500 RPM, if that's where the problem begins.
It would still pump the bucket dry if below 1500 RPM.

Everything I have seen here suggests to me there is a problem in the fuel supply line.

If you hand pumped 5 gallons of fuel through the filters without the engine running,
The one way valve in the lines that keeps the fuel from draining back is faulty and
you are pumping it into the tank.
Joe Laird
'78 Eagle
Sioux Falls, South Dakota

Offline treeplanter

  • Full Member
  • ***
  • Posts: 111
  • the grey ghost,1971 GMC 5305A
Re: 8v92T
« Reply #11 on: March 15, 2014, 10:34:47 AM »
Maybe try replacing the fuel restrictor?
Timothy

Online luvrbus

  • Hero Member
  • *****
  • Posts: 19434
Re: 8v92T
« Reply #12 on: March 15, 2014, 11:58:14 AM »
It could be his engine has fuel modulator or a throttle delay that is out of adjustment if the engine has either
Life is short drink the good wine first

Offline robertglines1

  • steam nut
  • Hero Member
  • *****
  • Posts: 4365
Re: 8v92T
« Reply #13 on: March 16, 2014, 07:46:19 AM »
ck hot side of turbo.. Exhaust manifold gasket.   look at bottom especially  loss of exhaust pressure = loss of boost=loss of power. Just a guess and it happen to me. Also I have found on the 98 I'm doing now the fuel supply line is dry rotted and was sucking a minute amount of air under high demand /also look for a rubbed place against a line or surface.. I replaced it from tank back. I would not have thought a braided coated line wound deteriorate in that short amount of time--was in a non heat area where problem occurred. Also while we are covering the non-usual on one engine I had a valve spring break and the engine fall off a couple hundred rpm.  Since there are more than one the engine ran but preformed low. That was a hard find. Easy with valve cover off.   One more low voltage to your DDEC anything under 11 volts. If you have multiple batteries the feed to the DDEC  is normally fed off only one =If that one is weak= low ddec feed=  That's all I got.
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana

Offline Nineforever

  • Nineforever
  • Full Member
  • ***
  • Posts: 142
  • 100 klms south of Yellowknife NWT Canada
Re: 8v92T
« Reply #14 on: March 16, 2014, 07:59:07 AM »
Ive  tryed everything but the Colapsed exhaust ..... i notice the steel braided fuel line off the primary fuel filter has been rubbing on the barn door where the licence plate indention is .... it just might be getting air all get a new line made up at Wajax in Yellowknife Monday in the mean time ill pull the muffler off ... see if runs full power after 15000 RPM .... it is smooth as silk till hits 16000
Thanks
Dave
Hyway 3 100 klms south of Yellowknife NWT Canada