I bought a 98 discovery and had a mechanic swap out the transmission and transfer case.when I went to pick it up it was horrible. The engine idles so rough it hardly runs. It however will stay running but surges. If I press on the gas it bogs down and will back fire by the front of the engine compartment but the car will not move due to lack of power? The mechanics said they couldn't figure it out and pointed me towards the ecu. Now that the car is back home I'm getting codes p1314, p0300, p1316. All misfiring codes I believe. I have replaced the wires, plugs, and MAF. I pulled the plugs and they're black. Any ideas what this could be??? thanks in advance

 

How did the engine run before the trans and xfer case swap? Why did you do the swap?

 

Engine ran fine before swap, I would drive it for maybe 10 min and it would lock up up and not drive for a few hours and then the Same problem again. I would get severe grinding noises so we decided to swap the tran and xfer case. Now it runs like crap

 

"it would lock up".... as in the wheels would not turn no matter how much throttle was applied?

 

have you check adjustments such as transmission kick down cable

 

getting spark? check coil pack and distributor ? also when you pull the cap on the distributor to examine twist the rotor gently and see if there is any play you might have a broken spring.

edit:
https://landroverforums.com/forum/di...g-p1314-16764/

 

Well, that would be coil pack OR rotor. Probably has a coil pack.

That sounds like a timing issue to me. I would look for things that might have been disturbed during the swap. I wouldn't run it too much like that, or you will burn up the cats quick.

Crank sensor maybe? Maybe they boogered up the reluctor ring on the flywheel? That certainly would cause timing issues. And usually when the sensor goes sideways the truck won't start.

Bottom line; that truck ran when you took it to these morons and now it doesn't. Don't let them push that back onto you. Make them fix it. They caused it.

 

OK so I've done some more research, my mechanic has bypassed the alarm system in order to get the car running, I read that the alarm and ecu are synced together. Is this true that it can throw off the ecu and possibly why its running so rough? I mean It ran fine before bypassing alarm. If so how would I go about fixing the alarm, also when I bought the vehicle it didn't come with an alarm remote, and never had any problem until the alarm was bypassed

 

Ok one more time, then I give up.

Stop screwing with the alarm. Yes they are matched, and if you booger up the alarm box, not only will the truck not start, you will have to source a matched alarm and ECU, nearly impossible these days, and go through all the adaptive settings stuff to boot once they are swapped.

NOT YOUR ALARM. TIMING ISSUE. since you couldn't be bothered googling reluctor ring, I will explain it to you. There is a thing called a flywheel, a large metal disk attached to the crankshaft at the rear of the engine. It has a toothed ring around the outside, called a reluctor ring. there is a sensor, called the crank position sensor that mounts to the front of the bell housing pointing rearward. the face of the sensor sits very close to this ring and counts the teeth as they go by. The ECU uses this information to figure out where the crank is and information from a similar sensor on the camshaft to figure out when everything is in the right position to fire the spark plugs.

Now, if there are teeth bent or missing, maybe a lot of them, or the flywheel has excessive runout (its bent) then the sensor either isn't close enough or hits a hole with missing teeth and suddenly loses count. Since really bad things can happen if the cylinder fires with the valves in the wrong position, the ECU decides not to fire the plug to protect your truck.

Look, a transfer case/trans swap is no joke on these trucks. The transfer case, which bolts up first mates with the crankshaft just behind the flywheel. Now, if these jokers you are using didn't have the special fabbed bracket to hold the transfer case in the right position on the trans jack (I'd bet dollars to donuts they don't even have a trans jack) it would be an incredible hassle wrestling that thing in place because it is oblong and the position you have to hold it while sliding it on is nearly impossible to maintain. And it weighs a good 100lbs+. If they installed it without separating the trans and transfer case first, then double what I just said.

Look, the best option is these situations is to rely on Occam's Razor (Which in fine French fashion, he stole from Ptolemy):

"Entia non sunt multiplicanda praeter necessitatem".

or

"We consider it a good principle to explain the phenomena by the simplest hypothesis possible."

Don't go snipe hunting, LOOK FOR EVIDENCE. It ran, morons worked on it, it didn't run.

Something they did fuked up your truck. Don't look for gremlins, look for cause and effect. Thats where you will find the solution to your problem.

That's all I got.