My injector buzz sounds weak. I cycle through 3 times for colds starts (always have for some reason) but the first sounds weak, the second starts off weak but gets stronger, and the 3rd sounds strong. I checked the voltage (on, starting, and running) and it looks great! Starts fine as well but still runs weird until warmed up. Is it just me?

 

As the oil warms in the spool valve it will move quicker. I have a 05 I am working on which I notice the same thing.

 

You want the "buzzing" or "clicking" to be consistent.

Cycling the key 3 times is unneeded and hard on the batteries.

Josh

 

Agreed, I am of the opinion that the engine should be started within the first 20 seconds of key on ( before the fuel pump shuts off ) and cycling the glow plugs more than once is unnecessary.

 

Cycling more than once at this time of year is unnecessary, but when it's 0 or colder it seems to help to some extent to cycle twice.

3 times is foolish.

Josh

 

ok not to hijack the thread but on the subject of injector buzz with key on before crank, I dont think I even hear any buzz any more and the starts are inconsistent as far as crank times go. Is there significance to no injector buzz?

 

Should click/buzz every time the key is turned to Run.

Josh

 

Josh, it does, but for a very short time. Seems I used to hear the buzz/clatter for several seconds before the glow plug light goes out and now pretty much silent. Hey, it cranks up and runs better than ever but the starts are inconsistent as far as how long it takes to start.

 

At key on you should hear.
Injectors
Fuel pump
Vacuums pump
and maybe the instrument cluster and AC fan.


Sean

 

And if you don't hear vacuum or injectors...where do you start for troubleshooting?

 

First I would start with the battery, 12V : Check
Next Fuses : Check
Relays : Check

Once past the easy things I would start in with a good scan tool
not a SGII or the ones you can get a the local auto parts store.

But if you getting a lot of dead circuits I would be looking
at the battery protection relay to start with or the PCM relay.

The FICM relay is controlled by the PCM so if the PCM is not
getting the power then the FICM will not pass the buzz test.

What do you have going on or not going on?


Sean

 

Well to preface, my dad has a 2006 6.0 F250 and I just purchased a 2004 6.0 Excursion. He has had his truck since new, mine...has been through a few hands now.

On his, the vacuum pump is extremely noticeable, and cycles for a few seconds or longer anytime the key is turned on, usually we wait till it stops making noise before cranking and the injectors also make a distinctive buzz which is usually much shorter than the vacuum pump.

On mine, the vacuum pump is very quiet and rarely runs more than 1 second, without inducing a leak by pulling a hose off with the key on engine off. It does cycle depending on if it has built up a level of vacuum or not, but it is much quieter than the one on the 2006.

The injectors buzzing is also very short, almost impossible to hear past the initial dings from the key being turned to the on position.

When the vehicle is warmed up, it takes about 10-15seconds to crank.

IPR% when cranking goes up to about 60% but then falls back to 24ish while idling.
Oil pressure peaks around 1200 when it cranks, and hovers between 600-700 at idle.

I'm trying to figure out if the shorter/quieter cycles on the injectors/vacuum pump at key on has any bearing on the longer cranks when warm.

Also, if I do 2-3 shorter cranks it usually starts by the 2nd or 3rd try.

I didn't have the oil pressure reading or the IPR reading on my scan gauge earlier today so I will keep monitoring those for low/high readings once I get the engine hot again.

I have not taken a multimeter to the FICM to test the voltage on the screws, but the scan tool is showing 12.5v / 12.5v / 47-48v when the engine is running. Once it cranks, it seems to run smoothly.

Batteries are a few months old, were replaced as a set, and are not showing any obvious signs of distress. When its cranking it doesn't seem sluggish or weak.

I plan on pulling the Alternator and batteries out and running them to the local auto store for bench testing just to be sure, but I've put about 120+ miles on the vehicle in the past 2 days and had no other complaints other than restarting once warm.

I plan on replacing the fuel and oil filters this weekend, replacing the oil, flushing the radiator and replacing with fresh coolant just to get a clean slate there. The oil to coolant temp deltas are usually 5-7 degrees, max I've seen was 11 during a period cruising at 75, and it was mostly 9-10 delta.

We had to replace the FICM on my fathers 2006 truck around 120k miles, I am unsure if the one on my 2004 has ever been replaced, I'm suspect of the FICM, but I'd rather not just throw parts at it if anything else makes more sense.

 

Does not sound all that far off normal.
The injector buzz could be related to
what ever strategy is in the PCM and that
could also effect start times. One thing that
can and will effect starting is the starter.
If it's getting tired and turning slower.
Look at the RPM during start.
ICP will also effect start. You have to have
the minimum for the PCM to command it to start
giving fuel. Do you have early or later 04?
They moved the ICP sensor and if it's on the passenger
valve cover it a late 04. If not and it's under the turbo it's
an early and a pain to get at.


Sean

 

Its an 03 motor, an early 2004 production model. So I'm pretty sure its the not so fun one to get to. I need to poke around on it further during daylight hours, and get some more data points with the scan gauge.

The starter doesn't seem weak or sluggish, what RPMs should I be seeing while cranking?

 

Well...
I need to look that up and am not sure if they
list a real number. But ICP actual needs to be over 500 PSI
if my brain is working right tonight.


Sean