Parked my new to me '01 excursion after taking my kids for a hike, after a day or two went out to restart and cranks hard and strong but no start.

Ive been searching forums high and low and believe the UCVH's or IDM are to blame, any thoughts ?

This is what I've got so far:

no smoke out exhaust
IPR changed - Motorcraft.
CPS changed in 2016, possible aftermarket from Auto Z. (Changed by PO)
ICP sensor changed - Motorcraft.
fuel filter checked (no oil in bowl), bowl refills after being drained.
1/2 tank of fuel
WTS light comes on and turns off as normal
tach gauge moves during cranking - does this REALLY mean the CPS is ok ???
fuel pump turns on and pressurizes system like normal and turns off. - drained bowl and it refilled.
IDM pulled, looks clean from the outside, plan to test on my F250.

Injector buzz test fails - the tach jumps up around 3k for all 8, then jumps to around 2k for each individual buzz x 8.
Whats commanding the tach ? PCM, IDM ?
Why would they all just not buzz at once ?
Dorman UVCH's installed by PO - seem to ohm out ok.
Possible Auto Z CPS as well - Need to look through the receipts again.

Ohm from IDM Harness , first time I got 3.6 accross the board.
2nd time (week later) I get
Inj #2 - 5.8
Inj #4 - 4.1
Inj #6 - 4.2
Inj #8 - 4.2

Inj #1 - 4.1
Inj #3 - 4.1
Inj #5 - 4.2
Inj #7 - 4.3

After KOEO to test IDM harness for power got 12.15 @ Harness and 12.19 @ Battery (Truck has been sitting)
Inj #2 - 6.3
Inj #4 - 5.3
Inj #6 - 5.3
Inj #8 - 5.3

Inj #1 - 7.0
Inj #3 - 6.7
Inj #5 - 6.7
Inj #7 - 6.8

Is that normal after Glow cycle ?
Also, any chance the CPS is bad but tach still moves ?
Is it common for an IDM to just quit ? Shut down both sides of the engine ?

Thank you !

 

When my truck threw the P1316, it gave a engine light right away and the engine died and would not restart. Crank, but not start.

I replaced the IDM and the truck would start but ran very rough and had no power at all.

I did a buzz test on the injectors and heard one injector with a different sounding "buzz". Removed the valve cover to find a disconnecting UVCH plug. Did the .50 mod (well half of it) and that restored all to normal.
I copy pasted the above in a thread this AM and thought it might help here.

Do you have a constant CEL on?

Have a look at this THREAD

IDM signals the injectors when to fire. If no buzz test results, signal is not getting to injectors. My bet is bad IDM. I would try a known good IDM (if you have one) or send IDM for a test.

 

Your fuel bowl heater may be fried. This will blow fuse #30. You do not need the heater element unless you live in the great white north. unplug the connection at the back of the fuel bowl. check fuse #30, replace if bad. Does this help start the truck?

 

As this is an Excursion, and I have no experience with them, I read people have issues with PATS on Excursions. I have no idea what to look for but though it might be worth a mention.

 

Thank you for the responses, I have no CEL and had no DTC's until I started unplugging things and trying to turn it over.

I've checked the #30 fuse but will replace it just in case.

I have also looked into the PATS system and the light blinks normally and turns off after the WTS light goes out.

I have new UVCH's and VC's coming this week and will be swapping them out this weekend.

Thanks
Todd

 

Todd, I had something similar happen to me wayyyyy out in the woods once. Before the trip, I had the windshield replaced. The guys at the shop didn't hook the washer fluid hose back up, and every time my wife pushed the button it was pumping the fluid down onto the wiper motor and over to the IDM before hitting the ground. Well, the washer fluid got into the IDM plug and caused the IDM to lose connectivity with the PCM. When I pulled IDM, a couple tablespoons of washer fluid poured out of the plug. I dried it with a hair dryer, and all was good again. While it was down, no buzz test and no start just like you have.

 

The PATS system will rapid flash if it has been tripped/activated.

 

My first thought but dunno excusions

 

Mike, I'm thinking my IDM is bad. It was dry and cleaner than expected when I pulled it 2 weeks ago. I may hook it up to my F250 this weekend just to see if it's alive.
My biggest concern with just swapping in a new IDM is that high ohms through the IDM harness and I dont want to cook another IDM if thats what happened.
I'll be replacing my UVCH's tomorrow and will be ohming everything out again. The Previous owner installed the dorman gaskets about 3 years ago and I'm wondering if they've failed.

Pats system seems to be working fine, the light blinks normally and then goes out while WTS light is on.

On the upside, at least it quit running while sitting in my driveway and not out in the woods !

Thanks again,
Todd

 

Well I swapped my IDM fro the Ex into the F250 and the buzz test failed, so my IDM is clearly fried.
I've OHM'd out everything - UVCH at the VC and the IDM connector and I'm getting consistent 3.5's across the board.

Anyone know if IDM's are known to just fail ?

Seems that most of the info I've found on failed IDM's leads back to a shorted wire or bad UVCH's.

Thanks

 

Check your harness for chafing where it ride up over the driver's side VC. Then check your UVCHes.

 

Yes, they do fail from corrosion/water intrusion. Email Jonathan over at Diesel Tech of Chattanooga. He fixes them and PCMs. He can also upgrade it for you if you so desire.

 

Update: Purchased a reman IDM from RAE (Best deal and great customer service so far) installed it and turned the key and she fired right up ! Have been driving for about a month with no other issues.
Prior to installation I checked the OHMs at the IDM connector and also at the VC's and all numbers looked good. Apparently IDM's do just fail.

Thanks again for everyone's input.

 

Well the saga continues...
The excursion stranded my family on the 4th of July - was parked on a small hill, nose pointed uphill so I assumed it was a fuel / pickup line issue.
After having it towed home and parked with the nose pointing downhill she fired right back up, I filled the tank and took off for work the following day and just before making it to work she dies and left me on the side of I40. Had it towed back to my mechanic and all we can find wrong with it is a P0605 error.

It starts up after sitting for a day so I assume the PCM is resetting itself.

Anyone know if reflashing the PCM will correct the 0605 error ? I'm not getting any CEL's or anything else to make me the the PCM is bad.

Thanks