New Owner 2008 Trooper needs help

[Neil Wilson]

One more clue may be the PCV. The previous owner has disconnected the hoses to the fuel recovery canister. The ends of the hoses are plugged. The PCV is still connected to the wire harness so as far as I know it is still providing a functional signal to the ECU. Since the problem is intermittent I can't see why the engine would ever function properly if there were a problem here. Why would it work sometimes and not others?

[mixfixdave]

I am wondering about the fuel pump relay. The previous owner bypassed the pump and fan relays and hotwired them to toggle switches. This was because he had problems with corrosion in the  fuse box. In my review of the ECU and injector system I see the injectors are wired to the pump relay. I don't understand why. I don't know if there is a way to test the relay or the circuit. Any ideas?
 
PS, I am getting good pressure at the injector rail so I know the pump and pressure regulator are doing their jobs.

Make certain a toggle switch or wiring is not the problem. Especially if the switches aren’t waterproof.
Connect a voltmeter and tap/jiggle switches and wiring to see if anything seems twitchy.
I’d check voltages or resistance all the way to the pump and ECU. If the previous owner did electrical mods, I’d check them close.

[Neil Wilson]

12 minutes ago, mixfixdave said:

Make certain a toggle switch or wiring is not the problem. Especially if the switches aren’t waterproof.
Connect a voltmeter and tap/jiggle switches and wiring to see if anything seems twitchy.
I’d check voltages or resistance all the way to the pump and ECU. If the previous owner did electrical mods, I’d check them close.

Actually I just replaced both switches which had deteriorated. The pump is working fine as can be shown by the pressure at the injector rail.

[Dan B]

Sounds like the previous owner did so many mods that the ECU doesn't know what's going on.  I would suggest you undo all those mods and try get your ride back to factory configuration.  The hardest thing to fix is other people's problems because we just don't know what all they did to the machine.  Seems like you've also got some unknown, unfounded corroded elecrical connections.

[Neil Wilson]

No question there are some unknowns with the electrical system. I have to think the machine was working for the previous owner up to some point. Otherwise he would have undone whatever mods he did. The exception is if something had deteriorated to a point where he realized the cost to fix it was more than he wanted to deal with and he passed it off to me without telling me. The problem has definitely gotten worse since I got the machine, or at least the since the last incident. Again, the speedometer issue that has occurred has me thinking it is related.

[Neil Wilson]

As I am continuing my research I've learned there can be problems when the fuel pressure is too high. I know these machines should have about 50 psi going to the injectors. When I measured the pressure with a tester I was getting 100 psi. My pressure regulator is showing about 70 psi (evidently it is not accurate). As I have noted before, the engine runs fine when it runs, so I don't think this is the problem. However I am thinking I need to adjust the regulator.

[Neil Wilson]

19 hours ago, mixfixdave said:

Have you tried swapping the engine, fuel pump and fan relays...may help eliminate a bad relay?

So the fan, engine and fuel pump relays are identical. I tried swapping them around and it makes no difference. Assuming at least one of them is good, I don't think it is the relays.

PS,  I see now you already suggested this. 

[Neil Wilson]

On 9/5/2020 at 4:25 PM, Shaky Jake said:

Still sounds like bad grounding....just saying

Shaky Jake, it looks you had it right. I took it to a shop and they found the ground at the starter motor was loose. Apparently I forgot to tighten the nut when I installed the starter. I must have gotten distracted when I was in the process and lost track of what I had done. I tested it today for an hour or more and it ran flawlessly. Will need a few more runs to be sure it is fixed.

[Shaky Jake]

How has it been running? 

[Neil Wilson]

So far so good. I was having issues with overheating but it turns out the sensor or gage is wrong. I've checked it with an infrared thermometer and it runs around 200 deg. at 60 mph even though the gage is fully in the red. Last weekend my tail lights and overhead front lights stopped working so now I am back to solving electrical issues. I am happy with the machine overall now that I've solved the engine problems.

[cobaltman]

On 6/13/2020 at 10:38 PM, Neil Wilson said:

We took it out for our first ride and quickly discovered a loud banging noise when we go over bumps. Today we were with a friend who was following and he said the right rear wheel is bouncing freely. Evidently our Yearben shock is bad. So I looked up the Yearben shocks on this forum and see this has been a problem with these shocks. It also appears they are not repairable. If so I just bought myself a white elephant. This has been a nightmare experience for me. Anyone want to buy a Trooper for cheap?

if you wanna sell, call or txt me.  6604732747, jeremy