[Rock1127]

Sorry for all the threads recently, but alot of new things have been happening since my engine swap.

First the temp guage didn't work. Car didn't overheat or anything, so I know it's probably just a sensor. Well this morning was another story.

I was on my way to school, and at around maybe 25mph, the jeep started to buck and the RPM's went crazy. The rpm's would jump from 1500-2500 and back again over and over. It happened only twice, and letting off the gas and slowly applying the gas seems to fix it. All sort of things started racing through my mind. TPS, tranny fluid, ECM, everything. What could have caused this? It seems to drive fine, and i'm not sure what caused it. I'll see if I can get it to re-occur on my way home and then update then. But man was it scary! I hope everything's alright. Engine accelerates/stops/shifts fine.

Thanks in advance.

[hambubba]

Sounds like it could be a vacuum problem. Might be time to do the "reboot", also.

[Rock1127]

Well it drove fine on the way home today. I noticed that another problem occurred in the parking lot at school. It seemed to almost lose power in stop and go traffic after I give it a little gas and then immediately hit the brakes. It doesn't happen all the time, because I tried to make it happen again around my house so I could see for sure what it was.

The RPMs would drop and it would almost die and the whole car vibrates a bit, like it isn't getting fuel.

So that, along with what happened this morning. Where would I start to check a vacuum problem? And what is a reboot? Thanks for the reply.

[Rock1127]

I'm going to go out in a bit and check everything. I'm going to clean the throttle body and check the plugs and whatnot.

I have never cleaned the throttle body, never really had to. How do you do this? Just wipe any carbon build-up off?

[Rock1127]

Sorry for all the back-to-back posts.

I went out and wiped alot of the carbon that had built up in the throttle body. It seemed the breathe a bit easier and the problem didn't reoccur, but then again I only took it for a short 5 minute drive. It may have something to do with the engine being cold, not sure yet. I'll have to see how it performs tomorrow morning. Aside from the hesitation problem, it seems to run a bit better. Maybe it's part of the engine break-in process? I hope it's a one time thing that happened.

[fotonm]

After having this same problem on my 94 with a 5.2 I changed EVERYTHING that people have been talking about on here the TPS, New Tranny, New fuel filter, New fuel pressure regulator. Sometimes it would run great then other times just very sluggish and especially between about 1000 to the 2000 rpm mark. It didnt matter if it was hot or cold just very frustrating and intermittent.

Well I started to suspect a vacuum leak. While monkeying with the vacuum lines and wiggling them I got a surge and thought I was on to it. It wasn't the vacuum after all.

It was the wires that go into the TPS and when I would wiggle them it would surge and even cut off the engine. I unplugged it and Ohmed out the wires while my ohm meter was plugged into and wiggled the wires and I didnt get any Resistance drop. I figure out that the pin that comes out from the ground part of the TPS was not making a good contact with the connector. When it was not making a good solid contact I would get the problem.

You can fix this one of two ways.... you can replace the entire plug assembly to one where the female end of the connectors make a better contact or you can take up the slack in the now too loose female end with a small piece of wire inserted into the tooled out female end (lol) and now it wont be like a hotdog in a hallway and will make a good ground. Plugged it all back in and now runs like it should with full power all the way through the spectrum.

This worked for me so you may try this!! Its a connection and grounding problem in the TPS connector not an actual prob with any of the devices.

if your grounding and connections in the TPS are not solid it spikes all up and down sending the wrong voltage to the rest of the injection system.