7.3 poor start

[SteveR]

I have a 99 with a 7.3 that wont start without being plugged in no matter what the weather. I have replaced the glow plugs and had the relay tested soo not glow plugs. It "gallops" like its going to start but just wont. Not even at 80 degrees out. Once it starts once its fine for the day..NO CODES
My mechanic has done some research and found a guy he knows at a ford dealership that claims its injectors. I trust him but it still doesn't seem right that heat in the block would fix an injector issue. Should I bite the 3000 dollar bullet or does anybody have any other ideas..

THANKS
__________________
ROBBINS PROPERTY MAINT.LLC
Woodsville NH 03785

 

[Mike]

How many miles is on this engine?

When is the last time a full service was done?

Is your fuel pressure OK?

How old are your batteries?

Has your mechanic done a compression test?

 

[SteveR]

Miles ar around 100K Service is good No compression check I dont recall if the fuel pressure was checked

 

[geonc]

It "gallops" like its going to start but just wont. Not even at 80 degrees out. Once it starts once its fine for the day..NO CODES


THANKS
__________________
ROBBINS PROPERTY MAINT.LLC
Woodsville NH 03785

100k mi eh....has the engine ever been "soaked" either by pressure wash or driving thru deep water?

With your stated miles, this prolly won't be an issue, but on the top of the HPOP reservoir--very front/top of engine there is a cover that has a sending unit on the pass side and a plug on the driver side...remove plug---with engine off--- and see if the oil level is within a 1/4" from the top BEFORE any attempts to start have been made.....

I would also look at the IPR [injector pressure regulator] located below the HPOP and fuel filter on the lower drivers side.... a brief description of what it does...

The PCM controls the high pressure oil system by varying the duty cycle of the IPR. The IPR controls the oil bypass circuit of the high pressure pump. 0% = full return to sump (open valve), 100% = full flow to injectors (closed valve). The PCM monitors the system with the ICP input. The PCM can control fuel delivery to the injectors by increasing the IPR duty cycle which increases fuel pressure through the injector nozzles.


Also look at the ICP [injector control pressure sensor] located near the front/valley side of the left cyl head---- what it does...

Feedback input. The PCM monitors the high pressure oil system to determine if it needs to be increased if load demand increases. It also uses this to stabilize idle speed. Volts in: 1.0 volt @ 580 psi, 3.22 volts @ 2520 psi.


hope this helps
GEO

 

[Mike]

Miles ar around 100K Service is good No compression check I dont recall if the fuel pressure was checked

Batteries last changed?

 

[howards@howard]

Hard start

Put a new Motorcraft relay on to be sure. You can't test them. Are your Batterys new and starter spinning fast. 500 RPM's

if it starts pluged in every time it's the glow plug system or starter battery or low compression like mine I need a new motor

 

[geonc]

As stated, cranking speed is important!
Howard is on the ball with 500 rpm being minimum so that needs both batteries contributing along with a strong starter...if you have had any fuel or oil leaks that ran down the starter side....it has contaminated the starter motor.

I recently finally got around to repairing a pesky fuel leak by installing a new lift pump....then the starter "suddenly" started slowing up....removed and disassembled it to find it full of road dust attached to the fuel mist.

Let us know what you find.....

 

[SteveR]

I understand the starter speed and all but this thing should start I have 4 other 7.3s so I am sure it should start Like I said it gallops I mean all but running Kind of makes me think of the older cars with a bad coil would run as long as the key was in the start position..I apreciate all the comments kepp them coming

 

[howards@howard]

Hard start

to answer you question no heat in the block will not help a injection problem.
If it starts ok when you have it plugged in and it runs fine when you have it started. Then you most likely have a Glow plug circuit problem or a starter problem. Is there white smoke out the tail pipe after cranking it for a few seconds??? If you have white smoke you have fuel in the piston you need good glow and good spinning speed to start it.

Some one ran my truck with a bad air filter I have no compression left. thats how I know so much I have done it all.

I have the name of a highly recommend ford diesel tech out on his own in gloucester MA if you want it.