2004 mack cx613 vision

[Playinghooky13]

First the truck started out as not starting while the engine was at operating temperature now it doesn't want to start when cold. A little starting fluid will start it hot or cold. After the first start it doesn't matter if it runs all day or 15 minutes it will not restart on its own without spray. Trucks runs normal after it starts. This is the ac etech 360 hp engine or whatever the right term is for it. There is fuel in the davco filter check valve is holding. Replaced the return fitting with the check in it on passenger side of engine. Fuel pump possibly? Just need some places too look. Thanks for the help

 

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Edited December 26, 2020 by Playinghooky13
Engine type

[Vmac3]

Hello PlayingHooky13,

When you turn the key in the on position does the dash light up? Is the malfunction indicator on (lightning bolt) on the dash? If it is, you can retreive the code by turning off the cruise control switch and press the set/resume switch down. It will give you a blink code. If it does let us know what the code is. 

If not, then it could be several things. Without spraying quick start, when you crank the engine over do the dash lights flicker on and off quickly? If it does it may be the battery voltage is too low for the engine ecu to get powered up, it requires I believe 9.5V to stay awake (if I remember correctly). This could be caused by defective batteries, too high of a voltage drop across the battery terminals (maximum voltage drop across the staring circuit on the positive side is 0.5V and the same on the negative side), or simply the starter motor has high internal resistance causing the battery voltage to drop below the ECU's threshold. Try cleaning all the battery connections and the starter connections. See if the problem persists. There is also a ground cable that is on the left side frame rail and it goes to the left of the engine block. Remove it and clean all the negative terminals. 

It doesn't sound like a fuel issue you have because it runs fine after it starts.

But something to think about. It could also be the fuel pump. Did your vehicle have the fuel filter part of the fuel pump assembly and it has a plate to block off where the fuel filter lived? I have seen these pumps fail more often than the pumps without the filter. Fuel would bleed back to the tank and cause the same condition you are describing. The gear teeth in the fuel pump would wear out and instead of fuel being trapped in the pump it would pass the gear teeth. Use the hand primer and see if it starts more easily. If it does then it could be the pump.

Do you have any diagnostic equipment fuel pressure gauges and a multimeter? I hate to see you throw parts at it and not fix the problem. Its time consuming and can get expensive.

I think this will help somewhat. Let us know what you find. 

V

 

 

[Joey Mack]

Engine position sensor???? 3-2 right?  The 9-2 code can do that too...  You Go!! "V"

[Vmac3]

Good call. 3-2 or a 3-4. Engine rpm and cam position sensors respectfully. Power reset without key switch. Can be either of these. Also that model year had a bad problem with coolant wicking from the coolant overflow bottle. Coolant would wick through the coolant level sensor and into the engine ecu. 

Hopefully it a simple fix.

V

 

[Joey Mack]

i remember the coolant issue....Jojo

[Playinghooky13]

Ok I will see if I can get blink codes out of it today. I have a laptop with jpro but its not working at the moment hard drive crashed. Anyway I can pump the hand primer till your blue in the face with really no change. Just changed the coolant surge tank from the plastic 2 piece to the aluminum one from mack it came with a new sensor was hoping that would do it but it had no affect. Starter was replaced less than 2 months ago but I will check connections and ground. Batteries are a year old and did clean the cables and nothing changed. 

[Playinghooky13]

On the fuel pump it does not have a filter. Just the small gear pump with the plastic gear I know that those have been known to let the plastic gear spin on the shaft and not give proper fuel pressure but seems like u would have running issues.

[fjh]

Sounds like a fuel delivery issue !Check your oil level if its high the pump may be fubar! Is the primer getting hard or is it spongy if its spongy Fuel pump May be toast!    However rule out the stuff given you so far!

Also Did u check the ECU Plug for coolant push as directed? Its wurth a check!

[Playinghooky13]

I will check it in the morning when I get over to the truck. I dont think it makes oil but I'll have to verify that with the driver. I looked at the wiring for the coolant level sensor at the sensor and did not see coolant in the connector. I will look at the exam connections. Thinking about it now I remember trying to start it a few days ago and it will act like its gonna start for a second it did this a couple of times but would not go ahead and run. Oil psi while cranking is reading low runs at 25 hot at idle 50 while driving. It's hard to see exactly what it is while turning the engine over with the starter. I will check it out in morning and report back thanks for the help so far

[Joey Mack]

On a few issues, like youres, I have removed the teardrop shim behind the cam sensor, ( eng. pos. sensor) and the engine cranked up, did you check the condition of the RPM-TDC sensor in the flywheel housing? The engine can run on one or the other,(not very well) but will run. If the rpm-tdc is bad, loose, dirty, or bad wires, given its location, it gets a lot of dirt thrown at it.. the wires dangle and break down over time. anyway, you are getting a lot of help here, my thoughts are to keep it simple first, and fix what you see is broken.. Good Luck, jojo

[Vmac3]

I was able to dig up info. Measure the sensor depth using a nut, bolt and washer. remove the sensor(s). Screw the bolt in until it contacts the cam gear and the ring gear. Measure the bolt length. Here are the specs. The "P" numbers are the shims thickness in thousands of an inch. P30 =0.030". Too close or too far the sensor will not read correctly. 

Less than/equal to 1.328 (2) P30
1.329 through 1.343 (1) P15 + (1) P30
1.344 through 1.358 (1) P30
1.359 through 1.373 (1) P15
Equal to/greater than 1.374 None

V