[TUNINGBYAMG]

Hi guys,

I've been around this forum and i love the tech advice around here and the people.
Here's whats going on to my truck, all of a sudden it takes a good 20 secs of cranking to get it fired up where as before at the turn of the key and not even 2-3 secs and it would fire up. Its not a truck that gets alot of mileage and it sits outside under a covered tent.

Here's what i've done so far, mind you i have a 2nd one like it for parts in my back yard.

- replaced fuel filter, and gasket,
- checked hpop oil level seems to be about 1 1/4 from top of tank until i hit any oil by inserting a screw driver there, oil looks ok and has been changed recently
- engine runs fine once started no power issues or misfires or rough idling runs loud and proud on all 8
- what i've noticed is that there is kind of a needle valve on the right sided of the filter housing, i'm presuming this is the return fuel feed pressure test port and what i notice is that within 1 min of truck being shut off, if i press that needle nothing comes out. Would this be indicative that fuel goes back to tank and doesnt stay pressurized for next time im cranking it?
I've checked the o-rings of the valve body that bolts on the right side of the fuel filter housing and also replaced the metal valve held under a 19mm screw on the right side just on top of that needle.

All this to no avail and now i dont know where to look but it definitely feels like fuel is going back to the tank once truck is stopped

Any ideas?

 

[540milotalon]

First, I'm not an expert. I believe you won't see much pressure on the schrader valve after shutting down. It's what she does while cranking and then running that is most important. Should be about 5o# with tire gauge. HPOP oil level should be within 1" from plug hole I believe. Are all these starts cold (depending where you are) or, first starts of the day? Do you get white smoke while cranking? Have you tested glow plug relay?

 

[TUNINGBYAMG]

Well no smoke whatsoever, the relay clicks and i see the light
engine was rebuilt like 2 yrs ago with valve cover harnesses brand new
and all glows checked and replaced.
oh and im in montreal, canada, its 30C outside when starting
whether it will be first start of day or leeaving it for 2-3 minutes, same thing
looks like return pressure is gone and pump has to crank to rebuild that pressure back before it fires up

 

[TUNINGBYAMG]

I've tested the pressure on the shrader valve today and it reads 50psi i didnt keep it much longer cuz i got diesel in my face.
filter bowl is full about an inch lower from the edge. From what i've read on other forums this engine's systemd doesnt keep pressurized for the next start, the pump rebuilds all the pressure when its cranked

I also tried putting the nose of the truck in a ditch to see if the weight of the fuel in the tanks pressing downwards will have any effect on starting and it did not

also when it runs and i shut it off, and i try to restart within 1 sec
it still takes alot of cranking which i find now sounds more like a sensor or electrical problem

 

[sumter_f-250]

Just some advice...Don't crank on the truck for that long of a time. You will ruin your starter quickly!!

 

[action4478]

you need to verify the GPR is working .. Clamp a jumper cable camp on the 2 large posts & try starting it ...

 

[TUNINGBYAMG]

What do you mean by GPR? what does that acronym stand for?

sumter- i know i'm going to ruin starter and batteries if this goes on so thats why i want to resolve it as quickly as possible

 

[540milotalon]

GPR, Glow Plug Relay. If truck is already op temp you don't need glow plugs or wait on the "Wait to Start" light to go out. You do need the light working and cycling, just don't need to wait if you are at operating temp. I think you are correct it is a sensor problem. I'm racking my brain-didn't take long- and haven't thought of anything yet. When you changed filter, may have been a good time to clean screen. You can do a search on FPR -fuel pressure regulator- shim and screen clean. Don't try the shim till you know what your pressure is. 50# ain't bad right now, however, you may need to look at that screen.

 

[TUNINGBYAMG]

oh is it Glow Plug Relay, ok, but why would it redo this when its hot, lets say i drive it for 20 mins in summer weather by the way its by no means cold here at this time of year, and its still does it.
Does it need glowplugs to restart when hot?

That will be the first diesel i've heard of needing glows when hot

 

[540milotalon]

Just for grins, try unplugging the ICP on the front of driver side head. I'm going to try to send you some tech manuals.

1994.5 - 1997 7.3L Power Stroke Diesel - Ford Truck Enthusiasts Forums
97-15A 7.3L DI Turbo Workshop Manual
1996 Bronco/F-Series Workshop Manual

See if these help, i'm not too good at sending pics yet.

 

[TUNINGBYAMG]

Thanks 540, ill try unplugging that sucker tomorrow and i'll jump start the Glow plug relay as well

 

[540milotalon]

You are correct, if it's warm you won't need to glow plug it. If there is no white smoke (unburned fuel) then glow plugs are probably working and I would hesitate jumping them. Again sounds like sensor because lack of fuel. You can check with test light if you want. Your problem you state does not change with warm engine. Do you have access to a scan tool or A/E-Auto Enginuity ?

 

[TUNINGBYAMG]

Look at this bad boy, he's begging for your help..

Lol, ok i shorted the GPR and before doing that measured with a test light at the uncharged terminal, and when the key is turned it does get power and i hear it clicking. I unplugged the ICP sensor and truck ran for a minute before shutting down by itself, check engine came on.
Scanned for any codes in the computer, no DTC's present.
What am i missing??? And i think i exaggerated by saying it cranks like 20 secs, its more like max 10 secs of cranking before starting. I also had a battery charger plugged to see if i'm not missing craking amps and the same issue is present still takes too long to start.

Any ideas anyone? Please help black stallion salvage his starter and batteries before winter comes :nono:

 

[SteveBaz]

Check the CPS a bit


CPS PROBLEM

This applies to all PowerStroke motors from late 1994 to 2002.

Diagnosis: A bad cam position sensor is usually signified by the PowerStroke motor abruptly and unexpectedly quitting. The motor may also be suffering from slight power loss and slight increase in fuel usage which is usually not noticeable until it is seen as an improvement when the sensor is replaced. When the CPS causes the motor to shut down, the tachometer will not register. If the motor fails to restart, the tachometer will not register when the starter is turning the motor over. This may or may not cause the check engine light to come on.

Part Numbers: The International parts are usually half the price of Ford's, and I wouldn't buy one from Ford unless you absolutely had to.

International part numbers:

A change occurred mid way through 1997, so if you have a 97 it is best to look at the engine serial number. For serial number before serial number 375549 use PN# 1821720C98. For serial number 375549 (including this number) and after use PN# 1825899C93.

Ford Part Numbers:

For 1996 and older use PN# F6T012K073A For 1997 and newer use PN# F7T012K073A

Remove/Replace: CPS replacement is a very simple process. It is located at the 10 o'clock position of the crankshaft pulley and secured with one 10 mm bolt. Removing the serpentine belt will facilitate the removal.

Step 1) Make sure key is off and disconnect battery or pull #9 fuse. This is always a good idea when working on engine electronics.
Step 2) Remove engine belt
Step 3) Unplug wiring plug from sensor by prying out on the little plastic tab and pushing it out of it's socket
Step 4) Use 10 mm socket with small extension to remove 10 mm bolt
Step 5) Clean any dirt or grease off of sensor and surrounding area to prevent contamination of crankcase oil and seal of new sensor
Step 6) Use pliers, pry bar, or whatever else to gently remove sensor by pulling it straight out. It may be slightly stuck and slight force may be needed to loosen it. It is ok to twist it in its socket to loosen it if necessary.
Step 7) Coat new sensor o-ring with clean engine oil and press sensor into hole.
Step 8) Replace 10 mm bolt, torque to 10 ft-lbs, or just make sure it is snug.
Step 9) Replace wiring plug by simply pressing it into position until you hear the holding tab click into place.
Step 10) Replace belt.
Step 11) Ensure battery has been disconnected or #9 fuse has been out for at least 30 minutes. After this amount of time, they can be replaced.
Step 12) Start engine and inspect for leaks or other problems. Make sure belt has been properly aligned on each of the pulleys.

 

[TUNINGBYAMG]

Thanks steve, that was the next thing i was attacking, thanks for the step by step procedure, i have one lying on my spare parts truck, ill take it off and replace see if it makes any difference at all.

 

[540milotalon]

Usually, when unhooking the ICP the PCM will set a default pressure and start/run. If CPS does not work maybe stuck or loose connector at IPR. Mine had broken retainer clips and kept losing contact.

 

[fourhatz]

If you can watch, I would see what ICP is while cranking.

 

[TUNINGBYAMG]

Update: ok here is what extra work i did, changed the CPS, changed ECU and checked all sensors for bad wires or loose connections, came up with nothing, problem still persists
i've noticed something though, if truck is left for 5 mins, it will take alot more cranking than when you shut it off and after 2 secs try to restart it.
What puzzles me is that with Quick start sprayed in the filter while cranking it fires up almost right away?

Could i have some kind of fuel issue or tank problem? Its really starting to get on my nerves now that i cant possibly find where this appeared from. it happened all of a sudden while the truck was sitting and wasnt driven for 2-3 weeks

 

[540milotalon]

Take a look at what dieselmanstech page has.PowerStroke diagnosis. I have got a few ideas for service/diagnostic help here. I'm a LITTLE LEARY of his suggestion of running the truck @3300RPM for 3 min. Try checking your screen in the fuel bowl/Fuel Pressure Reg. -FPR and see what happens. On the tech page dieselman says the truck should start/run with ICP disconnected ( others say this as well) you had truck cut off. Check again truck cold/hot.

 

[TUNINGBYAMG]

UPDATE UPDATE GUYS!!!!

I'm really starting to get disappointed here

Went to ford for diagnostic with their computer
they said what they see is while cranking it takes the HPOP all this time to all of a sudden jump to 500psi before that it stays at low PSI
They said
for sure its either 1. HPOP worn out or 2. IPR is stuck and wont regulate starting pressure

Here's the kicker, today i changed the IPR twice, cleaned the original one = same thing and i actually lost 1 cylinder now running on 7 as opposed to all 8
put another one known to be good and cleaned = same thing hard to start but once started runs nice and smooth on all 8
Decided to change the HPOP as well, and same thing
Also changed the ICP for a known good working one, not a thing changed
ran it unplugged, it runs but shuts off in 2 mins and check engine on

Whats next on the list? Injector leak??