2004 Genie Z45-25 man lift stalls out after start

[Ricothebear]

Looking for some assistance in diagnosing this issue. I'll be honest, not too sure where to start, but here's some background info.
Has the ford LRG 425. It's EFI. Serial number z452504-23852

Problem:
Starts up and runs ok first thing in AM for about a half hour. Once the engine starts warming up, it stalls out. Then it'll start up for about 10 seconds, then die.
Had 2 techs come out and look at it
1st tech said replace alternator (900$) and if that don't work, replace wiring harness (3000$).
2nd tech said engine is in bad shape, it's going to blow up soon, just a matter of time. Engine oil pressure is low causing stall.

I want to see if maybe there is more I can do to see exactly who is right?
If I can fix myself then bonus. I asked the first tech if I could just grab a ford alternator and swap it in to see if that fixes the issue, he said no, because there is special electrical sensors that come on the alternator that you can only buy direct from genie.

I am a part time automotive tech, have lots of experience fixing cars and doing some 12v electrical. This seems to be a different beast though.
I'm told that and malfunction will cause the engine to shut down like that. It is to protect other systems. (is this true?)
I see in the repair manual that there is a way to check codes, should I start there?
I also downloaded the wiring diagram and it looks not overly complicated, but it's difficult to determine what communicates with what.
I don't want you guys to think that I do not trust the techs that came by to look at the machines, I do, but I do find it odd that they both came to different conclusions.
Thank you for any assistance you can provide

 

[excavator]

I've had Genie techs tell me that only Genie alternators will work and I know what I say here will likely prompt some negative response, but, you can put a regular over the counter alternator on them. I've done it and have had no problems.
Have you checked the oil pressure when warm? Put a mechanical gauge on it and watch it, preferably just before it dies to see if your pressure is dropping off.
2 techs-2 different diagnosis, sounds pretty normal.

 

[Numbfingers]

Three thIngs will activate a shutdown on a Genie engine. Low oil pressure, coolant overtemp, and low alternator output. Check your temps, and verify your oil pressure manually like excavator said.

 

[Johndoe]

***On the side of the ground control box will be a toggle switch labeled "TEST" the check engine light will *FLASH* a self test code 1,2,3 it will flash that code 3 times then the stored codes will flash (each code will flash three times) it will start over when it gets back to 1,2,3.

***TECH # 1
Look inside the ground control box. If you have an ignition start module then a loss of tach signal will kill the engine ( failed alternator ), If you don't have an ignition start module then the alternator tach signal is not your issue. that being said a damaged engine harness can cause some strange symptoms.
***TECH #2
Low oil pressure is will destroy an engine and cause an engine to shut down.
you can unplug the oil pressure and the coolant temp switch. If the engine stays running, plug one in at a time to see which one kills the engine.

 

[Ricothebear]

Ok, just a quick update for everyone. The machine was delivered to our shop from site today so, I will have a look at it most likely this weekend, I'm going to buy an oil pressure tester tomorrow. Thank you all for your input I do appreciate it. I will keep you updated.

 

[Ricothebear]

Ok so I haven't had a chance to look at it too much this weekend. I did realize I at some point borrowed my oil pressure tester to someone who has not returned it. So I'm waiting on a new one from Amazon for now. But one thing I did notice was that the coolant reservoir was empty. The radiator appears to be leaking quite heavily from the far side of the rad. Its difficult to see without pulling the engine out on the swivel. The other thing is that it will not start and run for more than about 5 seconds now. Shutdown is almost immediate.

 

[Rentalmechanic]

These engines are notorious for wiring harness more so then the duetz. Use the test button on the side like johndoe started genielift.com has supplement manuals for the ford engine troubleshoot.

 

[Ricothebear]

These engines are notorious for wiring harness more so then the duetz. Use the test button on the side like johndoe started genielift.com has supplement manuals for the ford engine troubleshoot.

Just curious but do the wires get old an brittle from the heat from the engine ? I find it odd that a wiring harness can go bad so easily. Surely you don't have to replace the whole harness? could you not just find the wire that isn't getting continuity and depin the connector and add a new wire? or is it usually easier just to replace the whole harness?

 

[Ricothebear]

OK So I tried to find the oil pressure sending unit on the engine yesterday and found this.
One electrical connector that is not connected to anything and what looks to be a sensor missing its electrical connector. Is this the air temp sensor, coolant temp, or something else? I can't seem to find it on me electrical schematic.

 

[Rentalmechanic]

Not in use, that wire. I got to thinking are you hard throttling the controller when it stalls? Or hard turns on asphalt

 

[Ricothebear]

No, it actually only runs on high idle. if you put it to low idle, it stalls right away. Turning has no effect on the stalling

 

[Ricothebear]

I checked the stored codes. It was 5 , 3 , 7 . And 2, 4 , 2. I cannot find either of these codes

 

[Ricothebear]

Also, did they absolutely have to put the dang oil pressure sensor up between the intake manifold!!!
Who designs this? I'm going to have to remove a bunch of stuff to get it out.

 

[Ricothebear]

I tested the Orange w blk wire at the alternator for volts when running, shows 7-8 volts.
I unplugged the oil pressure sensor just to see if the engine would keep running and it didn't. ran for a minute then stalled out.
I can't get that oil pressure sensor out without removing the manifold or most of the wiring harness. So I'll probably wait until next weekend to do that.
I was going to test fuel pressure but i don't have the adaptor. Strange thing I did notice though, i pushed in the schrader valve to see if fuel would come squirting out and there was almost nothing. even right after it was just running. You would think there would be a good amount of residual pressure. I'll check fuel pressure tomorrow and see what i get.

 

[Ricothebear]

Presumably there should be some resistance at the oil pressure sensor correct? I ohm it and there is none currently, even when off. is this perhaps an issue?

 

[Johndoe]

fault codes
Original code 537 = Unable to reach higher TPS (Cross ref to 2112)
Original code 242 = Crank sync noise (Cross ref to 336)

 

[Ricothebear]

Mr John doe, the unable to reach higher TPS. Would that mean that the TPS sensor is perhaps malfunctioning? And crank sync noise, would that be the crank sensor ? I've never encountered these codes before.
Thank you for listing them though.

 

[Johndoe]

Crank sync noise = Engine turning over excessively but not starting (this is more of a statement than a fault)
Unable to reach High TPS = Would start by replacing your negative battery cable and testing the resistance of the grounds going to the ECM (Bk/Wh wire, looking for less than 1.0Ω)

 

[Ricothebear]

Ok so One of the supervisors recently replaced the battery not too long ago because he figured the battery was the issue. he also replaced the ground cable . I verified it is good ground.
As for the resistance of the grounds going to ecm, Should I be disconnecting the harness connector from the ECU, Put one probe on Black w white wire pin and other probe at battery ground? or just any metal area ?
I just want to make sure i'm doing this right. Thanks

 

[Ricothebear]

Tested the wire with one probe on battery and one probe on disconnected connector. Showed .05 ohms on all 3 ground wires ( 2 on one connector and 1 on the 2nd connector)

I did notice that there was some exposed wires behind the radiator, couldn't tell where they went, So I drained the rad, pulled it off and it looked to me like maybe these wires here could have been shorting out. They look really rough. They are from the crank position sensor, I'm going to repair those sections and see what happens.