Did I Find The Problem? | Fuso 4P10 No-Start

[@grahamkearnon6682]

You've certainly put off a used fuso now. Can't imagine breaking down in the bush with these issues.

[@BruceandKrista]

To be completely fair - until I find the issue - really this could happen to any vehicle… but yeah…. Not having fun with this one.

[@nickmorris13]

Have you checked the rail pressure with the factory diagnostic tool? I would think no HP pump drive would mean no rail pressure. If you think that drive pin is sheared you could maybe remove the fuel pump and see if the drive gear spins freely from that side.

[@BruceandKrista]

Hey, how did you see the next episode already 🤣. Great minds think alike!

[@ppereztorres]

Before disassembling the engine, is it not possible to connect a pressure gauge to the injector line to check what pressure is reaching them?

[@BruceandKrista]

Yep, I’m working on getting the parts to do that if needed.

[@lancegillies1395]

Bruce you are a champion. Do you know if your truck/engine got the recall for broken rocker arms and cam?

[@BruceandKrista]

Uhhhhhhhhh. It’s not something I checked - however when I bought the truck, the previous owner (corp) had “had all the recalls done” - but that could certainly be impacting this if there are issues there!

[@christopherwalcott4514]

Good morning ,I have A 2012 Mitsubishi fuso with this very same problem,no start but I narrow it down to the CP4 pump ,when I crank the motor there is not much fuel coming from that pump line asking for some guidance

[@BruceandKrista]

Keep following along with these videos, your issue may be the same as mine, but I don’t have an answer to my problem yet!

[@timobikes672]

Have you checked timing chains? Did it jump timing? Also a leaking fuel injector could be causing no rail pressure…

[@BruceandKrista]

Timing is next on my list - I’m not getting any codes for crank or cam timing - but still worth a check at this point.

[@isaackent2355]

"1.4 Resetting the engine control unit 1. Turn the starter switch to “ON”. Do not start the engine. 2. Depress the accelerator pedal to the floor and keep it there for at least 20 seconds. 3. While still keeping the accelerator pedal depressed to the floor, pump the brake pedal at least 6 times. When the engine control unit is reset, the indicator (amber) appears on the display for about 10 seconds. Worth a try

[@BruceandKrista]

Tried - unfortunately no change. Also did a battery disconnect, and shorted the wires together to drain any residual current, left for 24 hours before re-connecting. No change.

[@terrydou7938]

Janky, but if you think that pin is sheered, could you disconnect your low pressure pump (that you just installed), disconnect the fuel line going to the rail and drop it into a cup/bucket/fuelcan and turn the truck over to see if it's pumping anything at all? To find out if it's just your low pressure pump creating pressure at the injector and your high pressure pump is toast

[@BruceandKrista]

I could do that, but if it’s just the lift pump creating the pressure I’ll still need to know why the HP pump isn’t working. But that would tell me if it is.

[@td5def]

Have you done a injector leak-off test?

[@BruceandKrista]

No - but could be a good thing to do now that it seems I do have fuel to the injectors.

[@backbeatpat]

Did not see any atomised diesel appear from the injector you tried - as you kept the discharge hidden with the paper towel! That pin you mention reminds me of the 'pin of death' on a Cummins 6BT as it would work its way out and maybe wreck an engine. If your pin had come out would there be a noise reflecting its absence? If I were you I would go to the bathroom and check that all my yokes were atomizing.

[@BruceandKrista]

Ahh, but did you see any diese appear from the paper towel?

[@backbeatpat]

@@BruceandKrista fuel may well be appearing in the paper towel ......but was it atomized as like in a fine spray?

[@BruceandKrista]

Not appearing in the paper towel either, so unfortunately the pattern is nothing 😔

[@contributor7219]

Nothing new to add, I'm afraid: check fuel rail pressure before you go any further down the rabbit-hole; hold an injector in your hand with just the electrical connection attached while someone else cranks the engine, to confirm the injector solenoids are operating.

[@BruceandKrista]

Would be so much easier if my software still worked….😣. Working on a backup for that.

[@contributor7219]

@@BruceandKrista Diagnosis is certainly a lot easier with software in this day and age. What we do know is the engine has compression and isn't even trying to kick, so there is either no fuel pressure in the rail or the injectors aren't firing (or both).

[@BruceandKrista]

Haven’t measured compression yet - could be a timing issue…

[@contributor7219]

@@BruceandKrista Compression sounds good when you crank it - four distinct compression cycles. Usually they start to 'run into each other' when compression is down to the point a diesel won't run. Injector timing is set by the ECU from the timing sensor. Even if the timing was way out the engine would still be fuelling and every now and then there would be enough fuel in a cylinder for it to 'kick'. The only time I've known these to not kick at all from timing is if the timing sensor has failed (it will fail the injector click test then) or if the timing chain has broken completely - extremely rare. I'm betting money on either very low fuel rail pressure, or the injectors are not cycling.

[@BruceandKrista]

I’m thinking the same - somehow it’s not firing injectors, either because of low fuel pressure, or because it thinks it’s low fuel pressure

[@BadGam3in]

I have a fuso bread truck and i had to start it for months with starting fluid before shop found there's an in line filter near the fuel tank that was completely plugged up not allowing proper pressure, and they took the valve out of the cp4 pump and lighty sanded it smooth.. they said just a lil bit of trash in the cp4 valve will not allow enough pressure for starting

[@BadGam3in]

I would definitely just spray a lil staring fluid in the air filter housing and see if it runs fine after starting, if so that cp4 pump is dirty and not making 20,000 psi

[@BruceandKrista]

What did they sand on the valve??

[@BruceandKrista]

I’m going to verify the intake is clear, and the intake valves are opening first.

[@BadGam3in]

@BruceandKrista not sure now that I look at a cp4 pump I'm thinking they unscrewed the top part that has that big star bit and their is a lobe on a pressure spring in there, but I ended up getting a new cp4 pump about 6 months later anyways

[@BadGam3in]

@BruceandKrista I had another no start problem awhile ago and I just ask them how they fixed it and he said they replaced the map sensor on top the intake manifold, my boss said he thought it was the crankcase pressure sensor not sure where that's located tho

[@ljprep6250]

Clear plastic bags can also catch atomized diesel while showing you the pattern and volume. (Next time?) Dayum, that engine isn't playing fairly with you, Bruce. Now watch it be a broken ground strap somewhere.

[@BruceandKrista]

Hmmm - could pull all the injectors and put them in bags and crank - that would be interesting. I’d love a broken ground strap at this point!

[@BarontheDoberman]

#duramaxSWAP

[@BruceandKrista]

LOL