Ford F-250 & Ford F-350 The heavier duty full sized trucks from Ford, offering bigger, more powerful engines and drivetrains for the abuse they may go through in the workplace.

99 f250 7.3 knocking hard to start!

Thread Tools
 
Search this Thread
 
  #1  
Old 10-11-2008, 04:09 PM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default 99 f250 7.3 knocking hard to start!

hey guys im a newby here but hoping someone knows whats wrong with my truck...
i needed to move the truck quick and didnt let it warm up, this is the first time i ever did that so im woundering if it had somthing to do with it.it up made it to the end of the driveway and all of a sudden it started knocking and pinging an the sevice engine soon light came on. i put it in reverse and barely got it back in the driveway i had to push it cause it has no power. i let it sit for a few hours tryed to start it again and it did but sounds real bad! but the service light went off. iv seen many post saying #8 fuel injector, cam sensor, fuel pump, butterfly in exhaust can stick,throttle sensor. but i dont have a clue and dont want to go buy parts i dont need.
i changed the oil and filters last week.

any help would be great!!!
THANKS: GOOSE

1999 F250 SUPERDUTY
7.3 DIESEL 293,000 MILES, AUTO
IT DOSENT LOOK LIKE A 2 WHEEL DRIVE BUT IT IS.
 
  #2  
Old 10-11-2008, 10:03 PM
Hayapower's Avatar
Super Moderator
Join Date: Jul 2006
Posts: 7,471
Default RE: 99 f250 7.3 knocking hard to start!

First thing to do would be to retrievethe code.. A 7.3 if starved of fuel will 'hammer and rattle' something horrible, as well as suffer major power loss.. The #8 injector cackle issue is more of a rod knock type sound, but usually is just an audible condition/concern.. The backpressure valve ifstuck orclosed will usually idle ok, but will have a loud 'hiss', more so as the throttle is depressed with a flat power performance until it opens.. Checking for a code if possible, for any fuel control problems and for a good fuel pressure/volumeis where I'd go....
 
  #3  
Old 10-12-2008, 08:25 AM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default RE: 99 f250 7.3 knocking hard to start!

thanks for replying - i will try to get a code and check the fuel pressure. i tryed to start it at the end of the day yesterday and it poured white smoke out the exhaust and wouldnt start. dont know if that helps in figuring out whats wrong with it?
 
  #4  
Old 10-12-2008, 11:14 AM
Hayapower's Avatar
Super Moderator
Join Date: Jul 2006
Posts: 7,471
Default RE: 99 f250 7.3 knocking hard to start!

Does the white smoke smell of unburned fuel, or the sweet smell of coolant? Coolant level changed?
 
  #5  
Old 10-12-2008, 07:56 PM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default RE: 99 f250 7.3 knocking hard to start!

smells like fuel...
i checked for codes there are non cause no check engine light.
i dont have a fuel pressure gauge to check it, im trying to get one.

i replaced fuel filter again and cleaned filter housing.
tryed to start it and it turns over and every once and awhile it fires but wont start.
from reading everything on the net. i think its the cam sensor not alowing it to fire at the right time???

but this is my first diesel, i feel like the slow kid in class when it comes to learning about how a diesel works.

i do apperciate all your help!!! do you think it could be the cam senor?
THANKS: GOOSE
 
  #6  
Old 10-12-2008, 07:59 PM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default RE: 99 f250 7.3 knocking hard to start!

IF YOU THINK ITS THE CAM SENSOR... WHERE IS THE BEST PLACE TO GET ONE?
 
  #7  
Old 10-13-2008, 05:29 PM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default RE: 99 f250 7.3 knocking hard to start!

i changed the cam sensor but still wont start. it acts like it wants to now but still just lots of fuel smelled smoke filling my garage! is it possibale there is just a bunch of fuel sitting in the engine making it not fire?
THANKS: GOOSE
 
  #8  
Old 10-14-2008, 03:43 PM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default RE: 99 f250 7.3 knocking hard to start!

anybody have this same problem? or have any ideas of what might be wrong?
 
  #9  
Old 10-20-2008, 07:25 PM
THEGOOSE's Avatar
Junior Member
Thread Starter
Join Date: Oct 2008
Location: AKRON OH.
Posts: 14
Default RE: 99 f250 7.3 knocking hard to start!

i used a clear hose to see that frame rail fuel pump is working, fuel tank is free of debree. the truck started off of starting fluid, so i dont think its electrical. do you think it would be the oil pressure pump or something else?
CAN ANYBODY HELP? PLEASE!!!!!!!
THANKS: GOOSE
 
  #10  
Old 10-20-2008, 11:44 PM
Hayapower's Avatar
Super Moderator
Join Date: Jul 2006
Posts: 7,471
Default RE: 99 f250 7.3 knocking hard to start!

When trying to 'assist' start a 7.3, it's a real good idea to disable the glow system by pulling one of the connectors/terminals off the glow relay otherwise you can get amean 'flame back' through the intake.. Better yet to not even use ether on a 7.3.. A better way if 'absolutely necessary' for a assisted start is to soak a rag with gas (not dripping) and hold it firmly in the intake pipe air stream as the engine is cranked.. A less violent alternative, but not recommended

Being your truck has close to 300k on the clock it could be a HPOP problem, or a high pressure oil bleed.. But,, when a 7.3 is started a few things need to happen (and must be checked) as part of the diagnostics..

1. First is a good healthy set of batteries so the engine can crank 'at least' 100RPM or the engine will not start since thePCM doesn't detect the CMP signal at less.. Without a CMP/PCM on line,, the injector driver module won't fire the injectors..
2. There must be good fuel pressure and volume, if the stats aren't known, it should be checked to ruleit out as a possibilityfor the no start , or more so for performance concerns under loads ect..
3. The HPOP (high pressure oil pump/system 'MUST'be able to produce 500lbs of oil pressure for the 'push' for the injection.

During a 7.3 diagnostic for a no start,, the first thing would be to look at the PIDS (Parameter Identification Display) or some call them parameter information with a diagnostic scanner.. It's a 'look into'the needed PCM system values input/outputs,,, like what PSI thehigh pressure oil is meeting, for example 500lbs for the startup, indicated cranking speed, an injector pulse present, IPR/IPC (injection pressure regulator/injection pressure control valuesand so on.. Reason for the long explanation is that without a scan tool for diagnosing a no start it's a little tough, although not impossible..

With close to 300k on the meter, it may be a good idea to check for spec HPOP oil pressures.. You can install/plumb a test gauge (500lbs or better) into the HPOP line at the head and read the PSI.. If you see 500lbs on a crank you should be ok there.. If the pressure is below spec., there's a few hose/plug combinations to test each head individual for injector oring problems as well as to help pinpoint banks 1-2ect.. Could be a IPR (pressure regulator) oring issue as well, or a IPR failure..

Fuel pressure can be checked at either head,, passenger/right head there is a 1/8 pipe plug inwards towards the valley up front between the water/fuel seperator and the head.. Left/drivers head is in the rear area of the head..

On the top portion of the HPOP reservoir, (under the front edge of the dress cover) there is a plug, remove the plug and make sure the engine oil is within 3/4-1" of the top..

The thing that is sketchy, is that it ran 'fine' correct? prior to the no start.. No running concerns?? Another thing I might check would be the PCM fuse,, if the fuel heater comes loose, it can short and will blow the PCM fuse but since the truck was running then died, probably not the cause but thought I'd throw that in as a check point since you cleaned the filter housing..

It's more of a 'rule out' the possible causes first, rather than guess what it is.. If your pretty sure the fuel pressure is good, the next check point would be the HPOP/system concidering your trucks mileage..

By spraying ether into the intake and the truck runs/starts for a short time doesn't eliminate fuel control problems as a far as electrical, since what its doing is running on the 'prime' fluid..






 


Quick Reply: 99 f250 7.3 knocking hard to start!



All times are GMT -5. The time now is 12:20 PM.