Jeep yj loses power while driving

CplRecon

New member
92 Jeep yj 4.0 runs fine for days and then it Loses power for a minute or two while driving and then revs back up. I stay on the gas it acts like it wants to stall then it takes off. Any idea what it's doing?
 
Update: trying to figure out why my jeep loses power while I'm driving. Drive great for about 30 minutes, then I feel a "sputter" like it cut off fuel for a second (randomly happens).

I replaced the distributor rotor and cap. Replaced spark plugs and still no resolution.

Got a new gas cap, the fuel pressure checked.
No resolution

Afterward countless searches on reads about similar issues, one stated they changed the fuel sending unit and another said they replaced the MAP sensor..which both resolved their issues.

I purchased a new gas tank , new fuel pump sending unit kit, new hose, new vents, new fuel filter and new MAP sensor.

Installing them all at the same time next week. Hopefully this will solve my problem. If not, I'm not sure where to check next.
 
So 30 min in and the jeep starts to sputter and looses power.
What temp is the engine at?

How many min does it take for the engine to reach operating temperature? 195 deg??

Does it seem like a certain pedal position?

There are tests procedures for determining the fuel pressure issues.
 
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Around town jeep drives fine. On certain day i'll drive 35 freeway miles one way and on the way back, (another 35 miles) the jeeps starts to randomly loose power, feels like it looses fuel or "sputters"...i press on the gas pedal and it to act like its looking power, i down shift and then its ok and they randomly does it. Temp remains constant..doesn't change..unless my thermo doesn't work... I hope i'm explaining it right. I'll look into the TPS once the new gas tank is installed.

Gas tank is being installed next week. I'll post the results.
 
If it seems like a certain pedal position the TPS is failing or really dirty. Only use OEM sensors.

This can also be a clogged cat or failing O2 sensor, by your description.

There are tests to verify some of this before you spend a lot on parts.


When is the last time regular maintence was complete? Clean battery terminals and ground ends? Change spark plugs...
 
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Greetings..

The gas tank installation should be completed by Monday / Tuesday 02/22 or 2/23, then i'll take it for a looooong test drive. I will post my result and if the issue was fixed by the end of next week.

Here is what i purchased and replacing:

Champion Spark Plugs
New Distributor
Gas Cap
Gas tank filler & vent hose
Fuel Pump Sending Unit
MAP Sensor
Fuel filter
New 20 Gallon Gas Tank
Gas Tank Emission valve and Gommet
OUCH $$$$
 
2/2616
Picked up the jeep with all the new parts installed.

Problems: losing power / sputter while driving and fuel gage needle bouncing when less than 1/2 tank.

Both problems solved! Needle is steady and I drove it with no loss of power!! So far so good.

I'll update on a week.
 

3/01/2016:
I drove My jeep for awhile now..and i haven't had the loss of power issue...however..while cruising to the car wash...i noticed a problem. As I lightly placed my foot on the gas pedal, i notice the similar issue of the jeep wanting to stall / coughing like as if it was clogged and barely getting any gas..but when I add more pressure to the gas pedal..it's find. So I fixed the long distance problem but now a have a short distance problem.

JPNinPA mention to check the TPS sensor...You were right..i hope.

Picking one up today and installing it: Will post my results.
IMG_2310.jpg IMG_2314.png
IMG_2318.jpg IMG_2319.jpg
 
4/13/16

jeep ran fine, however 2 weeks ago it started doing the same thing. I'm stumped! As I'm driving the jeep and I'm cruising along, it starts to lose power. As I'm accelerating it suddenly loses power and sounds like an internal exhaust cough / pop, without a loud sound, then accelerates again. I don't know what it is . I have a replaced everything except for the Catholic converter and the engine. any thoughts?
 

4/13/16 jeep ran fine, however 2 weeks ago it started doing the same thing. I'm stumped! As I'm driving the jeep and I'm cruising along, it starts to lose power. As I'm accelerating it suddenly loses power and sounds like an internal exhaust cough / pop, without a loud sound, then accelerates again. I don't know what it is . I have a replaced everything except for the Catholic converter and the engine. any thoughts?


Did you use OEM parts or was it whatever the auto store had? I can't say enough about OEM sensors for jeeps.. https://www.rockauto.com/m/mobilecatalog.php

If it's your Catholic converter ....say your prayers!! :)


If the catalytic converter is clogged it will be bright red or orange after a short ride with the engine at temp.
 
ha ha ha /\ i was smiling about that also. catholic converters, they are like mormons and those guys that come to your door to talk about religion, ha ha ha.

joking aside, maybe you have some bad/dirty connections in the wiring? maybe corrosion and some type of bump jiggles it enough that it causes a break in the connection?

i don;t know, is there a sensor on the transmission bell housing, like the cherokee and grand cherokee? whats it called, a cps? crank position sensor?
 
Didn't use OEM TPS, but I just ordered one from Rock Auto (OEM)

Sensors in the bell housing?? I'm not sure, but I think it does. Will look into it.
 

There is a cam /crank sensor which I ordered. I ordered the OEM From rock auto. Hopefully that solves my problem. Will post my results once arrived and installed.
 
There is a cam /crank sensor which I ordered. I ordered the OEM From rock auto. Hopefully that solves my problem. Will post my results once arrived and installed.

FYI a cam sensor CPS is different from a crank sensor CKP.

CPS is a part of a distributor or ODPA , it reads the timing of the cam and sets the firing order of the plugs.

CPK is on the bellhousing reading the engine RPM. When this fails your engine cuts off.
 
Thanks for the info. I've been researching it on online.. it is the CPK.. Looking to purchase an OEM part from Rock Auot or Jeggs. Any suggestions? Hopefully this will solve my problem.
 

4/27/2016: I ordered and received a
New TPS,
New 02 sensor and
New Cam sensor.
IMG_4004.JPG
Hopefully replacing these will solve my issues...if not I don't know what else will.
 
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