Lr4 no start after coolant pipes replaced

[DaytonaRS7]

Some background, I'm new the land rovers. Just picked up my first, a 2011 lr4 HSE lux, with 138k miles, and the 5.0 V8...not sure I need to say that since it's the only engine. Anyway, I have been doing preventative maintenance, latest of which is the coolant crossover pipes.

The car has been driving great for the past few weeks, the length of my ownership.

The problem:
Car cranks, but doesn't start.

The cause:
I replaced both front and rear coolant crossover pipes.

Details:
I completed the work yesterday, and the car barely started. It had a very rough start and idled high. I realized I forgot to plug in the connector at the bottom back of the intake manifold. No idea what it is, if someone knows I'd like to know.

Today I unbolted the intake manifold partially removed it, just enough to get to the connector (referenced above) and plug it in.
I reinstalled the intake manifold and connected all the vacuum, pcv and fuel hose.
I go to start the car and it just cranks.

I disconnected and reconnected the battery, thinking it would reset any modules.
No changes.

Had the wife try to start the car while I wiggled the wire harness at the rear of the engine, thinking I loosened up some important wiring. No changes.

I removed and reinstalled the intake manifold again, thinking I maybe missed somthing. Nope, everything was connected.
Still cranks, but doesn't start.

Does anyone have any ideas? Is there somthing I am missing?

I'm not new the doing my own wrenching, but this has me stumped. Almost the the point that I'll have it towed to the dealer. This was a simple remove and replace of parts.

Fuel pressure is good. I know because each time I removed the fuel rail crossing the intake manifold, it was pressurized.

At no time did I remove the throttle body from the intake manifold and both the main harness and the map sensor are plugged in.

Thanks in advance.

 

[DaytonaRS7]

i realize it hasn't been posted that long....but anyone?

looking to get this running again and thinking it must be something dumb.

even wondering if its the crank position sensor? not sure how this would get affected by the coolant pipe replacement, but the symptoms are there.
when the car is cranking, RPM's show a steady few hundred on the tachometer.

I also cant seem to see the Crank position sensor on the car. unless its visible/accessible from below?

 

[TrinidadLR4]

I did this job a month or so ago and knowing how many connectors and vacuum pipes have to be connected/disconnected to get to the coolant pipes(especially the back one), I'd venture to guess:
1) there is a disconnected vacuum hose somewhere, creating a vacuum leak large enough to not start at all.
2) There is a sensor disconnected or maybe sensor plug is connected to the wrong sensor somewhere.

Do you have a GAP tool? Codes would shed a lot of light. When I reconnected everything and started the car, I was getting a restricted performance message. Couldn't figure it out until I pulled the codes, which told me that I forgot to reconnect the A/C pusher fan.

 

[DaytonaRS7]

i dont have a GAP tool, unfortunately. i do have a code reader, but not land rover specific. ill see if there are any codes. i haven't noticed a check engine light though, since the car hasn't even started.

At the first reassembly and start up, i definitely was missing a electrical connector, at the back of the intake manifold. when trying to start with that disconnected, it would crank, turn over, and barely stay running, sputtering around 2-k rpm.

After I removed the intake manifold, reconnected that plug, and reinstalled the intake manifold..the starting problem seems to have changed. Now it just cranks

Im trying to think of what i may have forgotten, and nothing comes to mind. which is also the reason i pretty much did this repair 3 times (removing and reinstalling the intake manifold)...thinking i had missed something.

there aren't that many things to remove. off the top of my head...
2 electrical connector at the throttle body (MAP and main harness)
1 electrical connector at the rear crossover pipe
1 electrical connector at the back of the intake manifold
2 pcv hoses
1 vaccum hose running across top of intake manifold
1 fuel hose running across top of intake manifold
assorted coolant hoses...not the problem as the system held pressure when i vacuum filled it.
i didnt touch the knock sensors or wiring in the valley, but made sure they were not loose the last time i removed the intake manifold.

a/c pusher fan? not something i know of. maybe i disconnected less parts than you.

im going to remove the intake manifold again later today to double check the gaskets. but even if they were slightly damaged, the car should have still started, just ran like ****.

 

[TrinidadLR4]

Right, if there is a vacuum leak then it should still start and run, albeit poorly. Maybe damaged some sensor wire somewhere? Also, you have fuel in the tank, right?

 

[DaytonaRS7]

anything is possible, but i don't think i was that rough when moving things out of the way. ill try poking/wiggling around the wire harness at the back of the engine today, while cranking to see if it makes any difference. ive already done this, but cant hurt to try again. ill also double check the map sensor and throttle body connectors for anything loose or broken.

fuel tank is 3/4 full, filled a few days prior.

 

[DaytonaRS7]

just a non-update....
unfortunately, still no progress.

yesterday when i removed the manifold (again), i made sure to take my time and inspect everything as I went along.

The car cranks very strong, and has no hesitation cranking, but also no attempt to run. I cant help but think this is a electrical, spark, or sensor issue that is not providing a correct signal for starting. Its inability to even start/stumble/stall makes me feel it is not a mechanical problem.

I am going to stop by my local dealer today and ask them if I can have it towed there. hoping they don't take advantage since they are technically fixing a failed DIY repair. even though i don't think the current problem is related to coolant hose install, rather just a [electrical] casualty.

 

[DaytonaRS7]

update...

stealership has determined that the plugs for the manifold diverter plug and the coolant temp sensor were swapped. $650 (after asking for a discount) to fix the problem. $190 diagnostic fee, $460 repair cost.

Im honestly surprised that those 2 connectors are interchangeable. oh well. expensive lesson learned. and hopefully some one in the future doing this repair finds this helpful.

 

[cperez]

Glad you got it sorted out. I wonder if the ~$500 GAP tool would have detected the improper connector issue?

 

[avslash]

460.00 to plug and unplug 2 connectors? Eeerk.

I could live with 190.00, but no wonder everyone thinks dealerships suck.