Could I ever use some help. Thanks to anyone in advance.

>>>2002 4-door Dakota with 4.7 liter/Automatic.

I replaced the 4.7 engine in my Dakota with a 4.7 crate engine. Everything went as planned, hit the starter, it started up immediately and idled like nothing had ever happened. It was purrrfect.

A couple of days go by, and while driving along the transmission kicked down into lower gear and stayed there, exactly the way you would expect if you were low in transmission fluid. (And, I got a ding-ding-ding warning sound if I drove over 42 mph).

I checked fluid and it was low, and noticed a small slow leak coming from the transmission-housing-to-engine-block (exactly where the torque converter is housed).

I put a little transmission fluid in it and all was good. Having just spent thousands on the crate engine, I thought I would simply have to keep it topped off for a bit until I could get the funds together to address the issue (which I suppose I apparently created in reinstalling the torque converter!?!?).

TWO THINGS THEN HAPPENED:

1) I noticed that when the transmission kicked down, the engine would run like dog cr*p. I would then top off the trans fluid, disconnect the battery for a few moments to "reset" the computer, and all would return to normal. Completely normal everything.

2) The transmission leak stopped several days later, and the whole issue went away for months. No problems at all.

AND NOW I AM LOST:

The slow transmission leak re-appeared. It kicked down. It ran like cr*p (almost like it was completely out of time, almost like backfiring). I disconnected the battery. I topped off the trans fluid and tried to restart it. It wont start, it backfires and stumbles and seems to be completely out of time.

If I stay on the started long enough and just FORCE it to start, it will start and run fairly normal, but the transmission still acts like it is low (staying in third gear I believe, and not allowing speeds above 40 mph).

CONCLUSION:

I am an idiot.

I could be facing two separate problems and mistakenly conflating them as a single issue.

I need my truck.

 

Oh come on...there's got to be a Dodge tech out there who can help me understand where the issue is...???

 

Is it throwing a cel?

 

The short answer is no. No engine/transmission code at all.

The only code I ever get refers to the "Interior Module" where the interior lights/headlights/door locks won't allow me to operate them until I pull the battery cable and reset the system. Happens once every blue moon.

 

Check the tps and map sensors. Mine both when and truck ran like major crap but something like that should throw a code so I doubt its that. Im trying to think of everything but when something comes to mind something else that you said cancels it out. Ill ask my dodge tech guy tom when I see him maybe he will have a idea.

 

Dodgeramguy,

Thank you very much. I would love to hear what your tech guy has to say.

When this was going on, I was thinking that the low transfluid kick-down was effecting the engine settings in order to force low speeds (perhaps as a safety measure). The very few times I accidently allowed the trans fluid to get too low (causing a kick down) I could get back to normal just by adding a little fluid and "reseting" the computer. Then as I said, it stopped leaking and I had no problems for months.

But for whatever reason the leak is back. I topped it off, but now it wont come out of the funky running that I was previously able to fix by simply reseting the system.

Now I am wondering if it was something else all along (seems unlikely), or has one problem been compounded by another (possibly), or if I even have a clue at all (almost a certainty).

Again, thanks. I will monitor the forum for any ideas you or anyone else might have.

 

gavinson,
I had a ford many years ago that had a very similar problem. Turned out to be a vacuum pot on the transmission that was there to smooth/soften the shifts. The diaphram in the pot would go bad which caused the transmission shifting to malfunction and the engine to run really bad due to the big air leak in the intake manifold via the vacuum pot on the transmission.
I haven't had my Dakota long enough to know if they have anything similar but your symptoms sound exactly the same.