[RedWagon]

So ive had a weird problem with my jeep lately ill be driving down and all of a sudden the hole vehicle jerks, rpms jump down low, it loses all power, then it goes right back to normal, a minute ago it happened to me and i pulled in the driveway and pulled it out of gear, i sat there a second then the roms went really low ( like 300-400 rpm ) then it went back to about 800 ( idle ) it did that about 3 times then died, i started it back up, moved it then it shut off again. Wtf is wrong?? Bad gas? Fuel pump/filter? At first i thought my clutch was going out but it still did it when it was out of gear and idling. I need to know this is my DD. Thanks in advance.

 

[DP40]

Check your ground wires first. Clean and tight, clean and tight.

 

[RedWagon]

Check your ground wires first. Clean and tight, clean and tight.

but it just started last week

 

[Big Sarge]

I would say you need to clean the throttle body and idle air control valve (IAC) see if that helps your issue, this is a common issue on TJs and free to give it a shot.

https://www.youtube.com/watch?v=Yc9ilkiRoTU

 

[86skl]

As said above, also ck clean and tighten both ends of bat cables, negative and positive, ck battery voltage with engine off and with it running. Ck fuel pressure at the rail with key on, then with engine running then while driving

 

[RedWagon]

Thank you everyone, i plan to find out the problem

 

[wildrnesxperienc]

Could maybe be throttle position sensor?

 

[Big Sarge]

Could maybe be throttle position sensor?

Not saying no, but highly unlikely as it did/does it at idle as well. TPS does not even have to be hooked up and the engine will idle fine.

 

[GrimmJeeperMI]

(Don't know if it applies to Jeeps but...)
I had a similar problem with my Grand National. I checked all the grounds, TPS and throttle body. On the GN there's a magnet sensor on the flywheel? When I cleaned it with some sandpaper, no more lunging, jerking other things you are going through. I don't know if Jeeps have those sensors. I'm too new to the Jeep.

 

[RedWagon]

I checked the throttle body a minute ago and it looked really good and clean and i checked the distributor cap and rotor button and they looked good, ( i also noticed a corroded ground strap ) i also need to clean my battery terminals but im still confused of what is causing the problem, could it be fuel pump, filter, injector??

 

[86skl]

You need to do the basics first, of which involves checking, cleaning and tightening of the batt cables then go from there. Diagnosing a problem starts with checking the easy stuff first. Have you checked all the stuff that was mentioned above?

 

[RedWagon]

You need to do the basics first, of which involves checking, cleaning and tightening of the batt cables then go from there. Diagnosing a problem starts with checking the easy stuff first. Have you checked all the stuff that was mentioned above?

I still need to check grounds but i highly doubt that is the problem

 

[Big Sarge]

I still need to check grounds but i highly doubt that is the problem

it is often the problem!!! Just try it, it is free!! You ask for help and are getting common problem solutions.

 

[86skl]

What's you voltage? Fuel pressure?

 

[RedWagon]

Seafoamed it today, runs a lil better, still didnt solve the problem, tomorow im gonna try to clean throttle body and battery terminals and maybe grounds

 

[Digger84]

Check fuel rail pressure or better still fuel trim data from OBD port when it is acting up as if it is due to low fuel pressure the fuel trim values will jump up

 

[RedWagon]

Check fuel rail pressure or better still fuel trim data from OBD port when it is acting up as if it is due to low fuel pressure the fuel trim values will jump up

I dont know how to?

 

[ChasUGC]

You didn't give the year of your TJ. But, based on the information of erratic RPM's, and dying, I would say to check the cat. It is a known problem with TJ's. In fact, there was a recall for certain years. If the cat is clogged/broken/defective, it would cause the same problems.

 

[Digger84]

An android phone or tablet

Torque pro app

And

A Bluetooth OBD2 dongle

And look up a youtube video on how to use it

 

[RedWagon]

Its a 99, if the cat is the problem ill just take it off and clean all of the comb out of it. Also i looked on prodemand.com and i could not find any recalls concerning this but it said it could.be crank position sensor or the iac