I drive a 2003 wrangler Rubicon with an automatic transmission. Recently, when I accelerate quickly (especially from a stop) the jeep will "lurch" several times and the RPM will drop. It's an instant loss of power, and it happens multiple times just going from 0 to 30. If I'm really light on the accelerator this doesn't seem to happen but if I go over 2500rpm it's almost guaranteed.
It doesn't do this while revving the engine in park, only while driving.
Any ideas as to what may be causing this?
Well I guess I'll start hitting up stealerships and see if any of them have one in stock.
This is my daily driver, so a speedy resolution of the problem is what I really need but I'd rather not sacrifice quality if I don't have to.
Have you checked the codes? Sounds like a fuel issue, fuel filter or clogged injectors, for a crazy guess? Run a bottle of injector cleaner through it, won't hurt anything. Then plugs and plug wires? I'm not a mechanic, that's where I'd go.
Plugs are just a few months old and I ran injector cleaner through it last month, as well as taking the injectors out and cleaning them off manually when I replaced my exhaust manifold. I guess I could replace them but money is very limited at the moment and I really don't want to just throw parts at it.
I would suspect fuel issues except for the fact that in park/neutral it has no trouble revving the rpms up high. This only seems to happen while I'm driving and always at the same rpm.
No check engine light. When I turn the key three times it flashes a code at me so fast I can't even read it, I'm assuming that's for the bad downstream O2 sensor I never got around to replacing. But that's only to monitor the catalytic converter if I remember correctly so I don't think it would have any impact.
There are no codes, I checked. The number displayed when I did the key trick was just the mileage. *facepalm*
The rear cat isn't the issue, as proven by the gaping hole I now have in my exhaust. How would I go about checking the pre-cats? I was thinking of just pulling the upstream O2 sensors but I don't know what affect that would have.
Well I took out my exhaust system, everything but the manifold. The precats both have a decent amount of material missing from them which I'd assume is causing the blockage. I've decided to replace all three cats to be on the safe side even though the third cat doesn't look too bad, and possibly the muffler as well (I'll see how it all fits together). I ordered the parts from Advanced Auto and Napa and hopefully will have them by the weekend.
I'm really hoping this fixes the problem. I was able to drive fine with the exhaust off but I didn't do it for very long due to heat in the engine compartment, so not sure yet if this is the solution or not. Once I get it all together if the problem persists I'll buy a gauge and check fuel pressure.
Update: While waiting on Mopar and Advanced Auto Parts to ship the exhaust parts, I decided to check the fuel pressure. It tested within the factory specifications. Is there anything else I can do while I'm waiting to rule out other problems?
I was finally able to recreate the problem in my driveway in park. I revved the crap out of it after a long drive until right at 5k rpm the engine began struggling and wouldn't go any higher. The fuel pressure dropped to 40 psi every time the engine stuttered, which I'm assuming is enough to suspect something in the fuel delivery system as the culprit.