Baja

I have been suffering from a slow loss of power and torque over a long period of time. The truck can now hardly get out of its own way, and it used to run like a bat out of hell. I have taken the truck to a number of mechanics, but no luck. I just got a call from the latest one (#4) and he, or his office said he replaced my TST #10, which I installed, with a Bosch plate. The office did not have any information about the new plate. I am really confused. I am not a great mechanic, but I have learned a lot through DTR and my own work on the engine, but I cannot see how the fuel plate could be causing the problems I have been experiencing. I have to admit, I have not driven the truck yet, but is there ANY way the plate could be causing a very slow loss of power and torque?

Lil Dog

Slow power loss?? Not really likely. The fuel plate will administer the same rack travel if the truck is new or old. Slow power loss could be an air supply problem or a lift pump issue, overflow valve or restriction in the fuel supply.
Mind my ignorance, I have not followed all of your threads.. Time to do a search....

kawi600

What kind of fuel pressure readings did you get? is the problem through the whole rev range or is it worse at the low end or high end? any smoke?

kd460

I don't see why this mechanic decided to change the fuel plate. Not sure on his rationalle for this. Like mentioned, the fuel plate should not be an issue. This was a gradual loss in power, which as indicated by others, can be from fuel filter, prefilter/fuel strainer (it's just before the fuel pump), leaky gaskets at said prefilter/strainer screen, leaky fuel hoses (yes they can allow air to enter but not show any signs of a physical leak), an overflow valve that is dying, or a clogged fuel pick up in the fuel tank.

Another thought is slipped timing. This can happen and if slight, you may not feel anything sudden.

Sounds like all the things mentioned need to be checked. Start with the cheapest, and work you way up.

If it were my truck, the first thing is the fuel filter (if not done), then the prefilter screen (can be cleaned, need to check sealing washers), then the rubber fuel hoses(lot's of fun but worth it), then the overflow valve (just buy a new one from Marty Tompkins-do a search). And yes, I would do all of those. Of course, I know it's obvious, but air filter? Then I would check for boost leaks (there was a write up on a homemade tester), then I would check for retarded timing. Also get a boost gauge to see what your numbers are at. If your running a plate, then you need that and an egt gauge. If your pump diaphram is leaking or the hose that goes from your pump to your turbo is leaking or broken, that will affect boost.

Does it smoke? If so what color, does it miss? If so all the time or at high speed or at low? Hard to start after sitting all night?

Did I leave anything out guys? Make sure you get that plate back. I don't understand why he chose to swap it out, unless he needed it for his truck.

rattlerbob5.9

Baja
First of all DO NOT let him keep the #10 plate I NEED one !

If your plate was the problem it would have had to have slipped backward and therefore allowing less rack travel so then you would just put it back where it belonged and tighten it down or if for some reason the governor arm is getting hung up on the lower end of the plate and not allowing full rack travel. Again the method of correction would be to adjust the arm so it hits the plate correctly not by replacing the plate. I would look at your injection pump timing
from your discription of power loss over a period of time do you have a lot of white smoke at a cold startup? The timing gear is a pressed fit onto the pump shaft and can slip not hard to correct though.
Rattlerbob

mr T

ur power loss may be due to anumber of reasons ...removing the plate and gettign adifferent one is not the solution....a #10 plate in stock position with stock gov springs may not give u the feeling of more power..because of the fuel curve at different rpms with that setup....the 10 plate works nicely with 3kgsks ...and pushing it slightly forward will give u more power....besides that i see ur timing hasnt been bumped and ur probbaly in need of a new overflow valve...do u still have ur cat on that thing? i know ur in California but that cat isnt helping u...prolly plugged nicely by now

good luck

Baja

Thanks for all the replies.
I have done the following in repairs and troubleshooting:
Compression check, new overflow valve, cleaned screen at the lift pump, new lift pump, new rubber hoses in all the fuel lines, new diaphram in the AFC, pressurized the intercooler at the filter housing, found two small leaks in some hoses, replaced them. I still hear a hissing sound from the AFC, but when I spray it with soap, no bubbles appear. It takes about 40 seconds to go from 10psi to 0. All new filters throughout. No cat in the exhaust. I have NOT messed with the IP pump at all, sort of saving that for last, and only when everything has been looked at.
The engine used to practically pull itself out of the truck @1300rpm. It changed to pull strong @1800rpm, now there is no pull whatsoever at any rpm, nothing. It feels like there is no turbocharger at at all. My gauge will read 25-30 psi.
I agree with the replies, that the plate is not the problem.

Baja

A few more things I should add:
NO smoke at all, sometimes a bit of a puff on start up, nothing else on acceleration @WOT. The truck starts instantly, cold or hot.

DPS

Are you getting any boost at all? Have you checked the bearings in your turbo to make sure it spins freely? Bearings can actually coke so badly that the turbo will not spin properly.

Josh

www.dieselperformancesolutions.com

Racer9

Sounds like a no-fuel issue. I understand the WVO loosens up any crud in the tank and lines. Check the fuel pickup in the tank, just blow compressed air in to clear it temporarly. Do you use a fuel pressure gauge? Might want to borrow one for a bit. Keep us posted.

kandgo

Sometimes the fuel tank vent will clog up and give symptons like you state, I have seen guys start replacing fuel pumps, and have thier injector pumps looked at all the while the tank is not venting itself. I would get your plate back for sure. Goodluck,,Rick

Baja

One more, I did have the timing checked when the problem first started, and it was set @ stock, 12.5. The mechanic, I hope, would have said something if my injectors were coked at the time when he did the compression check.
I am getting about 25-30lbs of boost, but no surge when it kicks in, which is around 1800-2000rpm (used to be 1200). Nothing at all, it feels like a it is just not there at all, but the boost is there. The turbo spun freely the last time I checked it which was about 6mos ago. My WVO fuel system is completely separate from the diesel, tank, filters, everything. This problem started before I made the modifications for the WVO, so I do not think it is related.
I also believe it is a fuel issue, just what? It makes NO difference if I am running on diesel or WVO.

dmanis

where does it idle at? could it be a governor spring problem? loose?

Baja

Idle is pretty much normal, but has dropped just a little.
There is and has been so much happening, I forget to list them all. The engine used to max out, standing, @WOT @2800rpm, now at WOT, it maxes out @3400rpm. It has changed along with the touque curve.

plow

Have you checked the AFC diaphram?