Odd issue...before it gets worse
 

I've been experiencing a quite odd issue the last few days. It seems my engine starts a little sluggishly. Its not an extreme change but it is noticeable. When this occurs it also seems to have no power, step on the gas and it wont accelerate much if at all. This is some times accompanied by random very short bursts of power. It also, the other day, and what seemed like some popping that sounded like it was coming from the front driver side. All these issues go away after a very short time (under 30s) and don't seem to happen unless the truck has sat for a little bit (4+ hours maybe?). Any ideas on what would cause this before it causes my truck to be inoperable?


edit:
Also, may be unrelated, but 2 weeks ago my 3 amigos popped on shortly after starting then cleared when I shut off. They haven't come on since. I've also have been having some reoccurring starting issues if the truck sits for more than a day. Wont turn at all, makes a faint click/thunk. After a few attempts it starts up like nothing was ever wrong. During this all electronics/lights work fine, I could turn everything in the car on full blast no issues just takes a few attempts to start.

Popping and crackling might be spark wires or coil breaking down, try your cold crank up in a dark place with hood raised and look for sparks. Can make carbon tracks on coils, etc. But these would be hard to hear with engine noise.

Another thing to check would be a device with a pulley starting to sieze up. That can be checked by "listening" to each device the belt runs over (except the big one at the bottom) with a stick or stethoscope. Or take off belt, and four hours later crank truck to see if noise returns. If it does not, turn each device checking for roughness.

New magnacore (7mm cause I needed them immediately and they didn't have 8mm) wires and a new coil pack from AB were replaced less than 2500 miles ago. I suppose its still possible.

The thunk and no crank sounds like starter about to give up. Fun to remove, use a couple of extensions and work from the front side of the axle.

how old is your battery? have you checked the connections? if it has trouble starting, then when it starts everything clears up in about 30 seconds, it could be a weak battery. the alternator would take up the load after 20-30 seconds of running and smooth everything out.

My guess (and I am throwing at you what I have learned from Savanna :D)
The crank sensor.

It is going out. And is affected by heat.
And, the signal is not uniform.


The popping is back firing on the driver's side.
Which is the side with the air cleaner and the MAF.

Please check ASAP for pending codes.

Hummm
Or your battery is under voltage.
If it is cranking a little slower...

The hard to start is:

1) Battery post cable has crud. Clean the battery cables and terminals.

2) Battery is failing.

3) Battery (-) to frame wire is corroded at the frame. Take it off and clean the wire terminal, the bolt and the frame member area where the wire connects.

Our D1 did this until I cleaned the frame wire.
That used to anger :( others who depended on the D1.

Battery is a fairly new (year old?) red top. It was lose from the PO causing weird issues but has since been tightened. I'll check the body ground cable and see if that has been cleaned since the truck rolled out of England. I was part suspecting the CKP since it was coming from that general area. It isn't throwing a single code though, I guess since it goes away quick enough it wont? I'll watch my pending TCs on my ultragauge maybe they pop and go away.

Head gaskets.

How many miles on the truck? One other possibility could be a failing fuel pump, either not holding pressure and bleeding back or low fuel pressure in general.

The truck has 108k miles on it. It seemed to run worse for a little longer one time about a week ago when I was very low on fuel (bottom of orange). If a fuel pump would also affect the sender that's another possibility. I filled it up and it stopped at only 20 gal so I should have had at least another 3-4 gal of space according to the gauge. My ultragauge also never reads the fuel correctly and says something like "cant find fuel sensor" when trying to access things in the menu. Not sure if this is the same for everyone or if it's an indicator of a failure.

IMHO the Ultra Gauge might not find the fuel sensor since it does not route via the ECU, it goes directly to the instrument pod. Certainly it does go thru ECU on some vehicles.

Dont use the UG for fuel level.
I change my answer, bad fuel pump.