Author Topic: What causes loss of power?  (Read 21863 times)

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #15 on: May 20, 2012, 05:31:00 PM »
Also, cliff I double checked my stop cylinder skinner. Seems to be backed off just fine but we are parked for a week in ludington Michigan so I'll play with it more later.


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

Offline Zeroclearance

  • Hero Member
  • *****
  • Posts: 531
Re: What causes loss of power?
« Reply #16 on: May 20, 2012, 06:24:43 PM »
Since no one has mentioned this.   If you are smoking underload or pulling a grade might have FOD damage to your turbine wheel OR compressor wheel.   It is rather easy to see the blade tips on the compressor wheel.   If the edges are rounded off or rough the ability to generate enough air will be greatly reduced.   The hot side turbine wheel is hard to view with the cartridge assy installed in the turbine housing.   I do remember you mentioning that you installed a new/used downpipe.   If anything got kicked into the turbine housing FOD damage would occur.

Last summer I planned on upgrading my S60 turbocharger as a upgrade.   Needless to say, I was shocked to see my compressor wheel chewed up.   Someone did not clean the air filter canister prior to installing a new filter.   It only take a few grains of sand, plastic or XYZ to wipe out the blades that spinning in excess of 75K RPM.

Offline Brassman

  • Sr. Member
  • ****
  • Posts: 371
Re: What causes loss of power?
« Reply #17 on: May 20, 2012, 06:37:50 PM »
Do your injectors have screens in the fuel inlet?

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #18 on: May 20, 2012, 06:41:30 PM »
Zero, thanks for the discussion. I did check the turbo intake and exhaust side thoroughly and there is absolutely no damage whatsoever to the turbo. No play, spins freely, no oil leakage. I was very careful replacing the downpipe and besides any debris would blow out the exhaust not suck in. Anyway there are no shiny or worn spots no turbo dragging, nothing. Checked very very carefully. Still really feeling like its not getting enough juice. I've always seen a bit of smoke when mashed at full throttle but haven't seen that at all lately.  Thinking of installing an electronic fuel pump inline and seeing if that helps. If so, I'm thinking the pump is on the fritz.


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

Offline Busted Knuckle

  • Hero Member
  • *****
  • Posts: 6706
  • 6 Setras, 2 MCIs, and 1 Dina. Just buses ;D
    • KY Lakeside Travel ... Just 4 the Fun of it!
Re: What causes loss of power?
« Reply #19 on: May 20, 2012, 07:33:10 PM »
Scott before "just" adding a fuel pump inline follow Clifford's advice to the "T" first!
He gives excellent advise for free. The quickest way to get someone to quit helping is to "not" take their advice. (and then to post that you didn't and still have same problem and still wanting more advice!)

Check fuel pressures, rpm's andsuch as Clifford advised then start shooting in the dark!
(trust me I've followed Clifford's posts for a long time and 99.9999999999999999999999999 % of the time is dead on the problem and the fix before most of us can finish reading the original post!)
;D  BK  ;D
Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

;D Keep SMILING it makes people wonder what yer up to! ;D (at least thats what momma always told me! ;D)

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #20 on: May 20, 2012, 08:09:12 PM »
Yes BK! Definitely will do. Just in a campground in ludington for a week and  appreciating the continued discussion. Someone posted instructions on where to buy and how to use the remote tach but I need some instructions on where and how to install a fuel pressure gauge.


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

Offline luvrbus

  • Hero Member
  • *****
  • Posts: 26067
Re: What causes loss of power?
« Reply #21 on: May 20, 2012, 08:13:54 PM »
Scott on top of the filter base you will find a plug to install a gauge

good luck
Life is short drink the good wine first

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #22 on: May 20, 2012, 08:15:37 PM »
Wow, start by checking the rpm with a hand held tach your 6v92 should be 2100 to 2250 no load then check the fuel pressure should be 55 to 70 lbs at full throttle ? does your engine have a fuel modulator sounds like you are not getting full fuel position at the injectors.

You really cannot tell if the engine is at full throttle by checking the linkage on the governor housing,the rpm check is a good place to start   

Cliff, is this rpm at full throttle? Floored? So I should tape the pulley aim the tach and let Wifey step on the throttle full on while I time it?


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

Offline Ed Hackenbruch

  • Hero Member
  • *****
  • Posts: 2984
Re: What causes loss of power?
« Reply #23 on: May 20, 2012, 08:56:37 PM »
I think that this is a first, :)  "exhaust is literally invisible".   Usually it is, " i have white, or blue, or black smoke out the tailpipe"   ;D
Used to own a 1968 MCI 5A and a 1977 5C.

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #24 on: May 21, 2012, 06:25:07 AM »
True story. I've always had a little bit of "feedback" from the exhaust color. But nothing now.


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #25 on: May 27, 2012, 05:03:17 AM »
Still haven't purchased the tach yet for my first tests (watching the pennies at the moment until we know what our income is for the month) but noticed driving down the highway last week that when I'm at full floored throttle, I can clearly hear the motor (exhaust is straight piped at the moment) but when I start to descend a long hill and the coach picks up speed, right exactly at 72 mph the noise of the exhaust goes away literally as if I let off the throttle which or course I didn't. Almost like its governed. Any thoughts? I promise cliff I will get the RPM numbers to you via tach but just throwing out another data point.


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

PSmith

  • Guest
Re: What causes loss of power?
« Reply #26 on: May 27, 2012, 05:55:52 AM »
Just a thought - on the photo-tach source. Check the e-place - I just bought one for 13.00 brand new.   Accuracy is just as good as the hundred dollar items. .


Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #27 on: May 27, 2012, 06:29:49 AM »
Nice! HF also has them for $30. Doable. So since I'll be doing this, I have to ask again how do I measure the RPM? Should I have wifey floor the throttle and then go measure the speed while throttle is floored?


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

Offline luvrbus

  • Hero Member
  • *****
  • Posts: 26067
Re: What causes loss of power?
« Reply #28 on: May 27, 2012, 06:50:08 AM »
I disconnect the throttle cable linkage and do it all from the rear it should go from idle to governed speed (wide open) in just a second and fall back to idle just as fast if not you need a rack adjustment .

 If that checks ok then hook the throttle linkage back up if it takes longer to go up to the top rpms and back down you have a linkage problem  (careful around the belt)


good luck
Life is short drink the good wine first

Offline Scott & Heather

  • Scott & Heather's buses: MCI-9 & MCI-102
  • Hero Member
  • *****
  • Posts: 4636
  • MCI-9 & MCI-102
    • Fresh Day Music
Re: What causes loss of power?
« Reply #29 on: May 27, 2012, 09:25:03 AM »
Got it! Thanks cliff. Will post results. :-)


Sent from iPhone via Tapatalk
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

 

SimplePortal 2.3.7 © 2008-2024, SimplePortal