95 2.5 running awful

[condorf]

i have a 95 2.5l auto with 104k miles. Ive replaced the fuel pump,fuel pressure regulator and just today a new fuel filter. The filer was absolutely terrifying looking when i cut it open. I just got it up and running after sitting for about 7 years and it ran great for about 50 or 60 miles then suddenly it sounds like its missfiring/popping and kind of chugging with loss of power and idling rough. When its first started up after sitting for a day or two its fine but soon as i start to drive some it goes to crap at around 3k rpms and runs awful untill its sitting for a while, if i stomp it, it does power through and seem to run better and just slightly pressing the pedal its not as bad. I cleaned the throttle body good and replaced the gasket when it was off. My only other guesses are badly clogged injectors, maybe something left in the tank that got sucked up into the new pump, throttle position sensor, intake sensor also. The cat is original and could be completely stopped up as well, i drilled 4 small holes and beat around on it today after the fuel filter and it didnt seem to do anything. The chain of events go new fuel pump and regulator, driving for around 50 miles then the issue came up, cleaned the intake and new gasket and new fuel filter. This thing is running me crazy because its so close to running great and i feel like its something im just not getting looking for. Any info or tips are appreciated.

 

[Gilaguy23]

After sitting 7 years you may have a fuel tank thats rusted, if its steel, and has already plugged up that new fuel filter.

 

[DOWNS]

95 should have a poly tank. But could be a bunch of crap from bad fuel in there but hopefully he cleaned it up a bit before putting everything back together again.

I want to see his fuel pressure numbers at idle.

OP did you do the 20 gallon mod while you had the tank out?

 

[condorf]

95 should have a poly tank. But could be a bunch of crap from bad fuel in there but hopefully he cleaned it up a bit before putting everything back together again.

I want to see his fuel pressure numbers at idle.

OP did you do the 20 gallon mod while you had the tank out?

i did not do the 20 gallon mod, and i did clean as much as i could out of it when it was dropped but its very possible i missed stuff, this is my first major vehicle project and a big learning experience. Im coming from very limited knowledge..always wanted a jeep and wanted a nice project vehicle as well. So there is very basic stuff i could of missed or dont even know to look for

 

[DOWNS]

We need to see some fuel pressures. Also go in and really inspect and clean your grounds. Many a running problem can be traced back to poor/dirty grounds and old corroded battery/ground cables.

 

[condorf]

We need to see some fuel pressures. Also go in and really inspect and clean your grounds. Many a running problem can be traced back to poor/dirty grounds and old corroded battery/ground cables.

ill have to get a fuel pressure gauge before long to test it.

 

[DOWNS]

They're cheap and easy to get.

https://www.amazon.com/dp/B0B9R5HF4D/?tag=yjforum-20

If you don't want to buy one for your self, even though I think it's a diagnostic tool every YJ,XJ or TJ owner should have on their shelf, you can rent one from any local parts store.

 

[condorf]

They're cheap and easy to get.

https://www.amazon.com/dp/B0B9R5HF4D/?tag=yjforum-20

If you don't want to buy one for your self, even though I think it's a diagnostic tool every YJ,XJ or TJ owner should have on their shelf, you can rent one from any local parts store.

absolutely will be buying one to keep, i have plans to keep the yj for a long while.

 

[Flyer58]

No engine codes?

 

[DOWNS]

Sounds like the OP is pretty new to all this. @condorf here is the procedure to pull any DTCs from the computer. Not all codes set off the check engine light so you might have some stored in there that aren't setting it off. Let us know what you find out.

• Insert the key into the ignition
• Turn the ignition On-Off-On-Off-On within 5 seconds
• Record the 2-digit DTC as displayed by the flashing MIL

I.E. - DTC 24 will be displayed by 2 flashes, short pause, and then 4 more flashes. If more than one code is stored, there will be a longer pause before the next code is displayed.

​

11​	No crank reference signal detected during engine cranking. Intermittent loss of either camshaft or crankshaft position sensor.​
12​	Positive battery input to PCM was disconnected within the last 50 Key-on cycles.​
13​	No difference recognized between the engine MAP reading and the barometric (atmosphere) pressure reading from start-up.​
14​	MAP sensor input above or below acceptable voltage. 5 volt output to MAP sensor open.​
15​	No vehicle speed sensor signal detected during driving load conditions.​
17​	Engine did not reach operating temperature within acceptable limits​
21​	Upstream oxygen sensor response slower than minimum required switching frequency. Upstream oxygen sensor heating element circuit malfunction. Downstream oxygen sensor heating element circuit malfunction. Downstream oxygen sensor input voltage maintained above the normal operating range. Oxygen sensor voltage too low, tested after cold start. (Upstream or Downstream) Left oxygen sensor input voltage maintained above the normal operating temperature.​
22​	Engine coolant temperature sensor above or below acceptable voltage.​
23​	Intake air temperature sensor input above or below acceptable voltage.​
24​	Throttle position sensor input above or below acceptable voltage. TPS signal does not correlate to MAP sensor.​
25​	A shorted or open condition detected in one or more of the idle air control motor circuits. Actual idle speed does not equal target idle speed.​
27​	Injector #1 thru 6, or any combination of individual injectors driver does not respond properly to the control signal.​
31​	An open or shorted condition detected in the A/C clutch relay circuit. Insufficient or excessive vapor flow detected during fuel evaporation emission system operation.​
33​	An open or shorted condition detected in the duty cycle purge solenoid circuit. (A/C clutch relay circuit)​
34​	An open or shorted condition detected in the Speed Control vacuum or vent solenoid circuits. Speed control switch input below the minimum acceptable voltage.​
37​	Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement. An open or shorted condition detected in the torque converter part throttle unlock solenoid control circuit. Incorrect input state detected for the Park/Neutral switch. Auto only.​
41​	An open or shorted condition in the generator field control circuit.​
42​	An open or shorted condition detected in the auto shutdown relay circuit. An open condition detected in the ASD relay output circuit. An open or shorted condition detected in the fuel pump relay control circuit. An open circuit between PCM and fuel gauge sending unit. Circuit shorted to voltage between PCM and fuel gauge sending unit. No movement of fuel level sender detected.​
43​	Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders 1 thru 6. (4 and 6 cyls.)​
44​	Battery temperature sensor in voltage above or below acceptable range.​
46​	Battery voltage sense input above target charging voltage during engine operation.​
47​	Battery voltage sense input below target charging during engine operation. Also, no significant change detected in battery voltage during active test of generator output circuit.​
51​	A lean air/fuel mixture has been indicated by an abnormally rich correction factor.​
52​	A rich air/fuel mixture has been indicated by an abnormally rich correction factor.​
53​	PCM Internal fault condition detected.​
54​	No camshaft signal detected during engine cranking.​
55​	Completion of fault code display on Check Engine lamp.​
62​	PCM Failure to update service reminder indicator​
63​	Unsuccessful attempt to write to an EEPROM location by the PCM.​
64​	Catalyst efficiency below required level. (Same as code 72)​
65​	Power steering high pressure seen at high speed. (2.5L only)​
72​	Catalyst efficiency below required level. (Same as code 64)​
77​	Malfunction detected with poser feed to speed control servo solenoids​

 

[condorf]

Sounds like the OP is pretty new to all this. @condorf here is the procedure to pull any DTCs from the computer. Not all codes set off the check engine light so you might have some stored in there that aren't setting it off. Let us know what you find out.

Followed it earlier, 12,33,55 nothing that would get any hints, thanks for posting that info

 

[condorf]

Followed it earlier, 12,33,55 nothing that would get any hints, thanks for posting that info

Cleaned the intake sensors, new plugs and wires, removed the 02 sensor to see if the cat was clogged and still having the same issues, it's driving me crazy I can't figure out what's causing it run like trash

 

[condorf]

It idles ok now, but about 2k rpms it sputters and pops/crackles like crazy

 

[DOWNS]

We need some fuel pressure numbers. Could also still be an ignition problem with the ignition coil. It's making enough energy at idle but at higher engine speeds isn't putting out enough oomph to jump that gap properly.

But I really want to see some fuel pressure numbers.

 

[condorf]

We need some fuel pressure numbers. Could also still be an ignition problem with the ignition coil. It's making enough energy at idle but at higher engine speeds isn't putting out enough oomph to jump that gap properly.

But I really want to see some fuel pressure numbers.

UPDATE

ended up being a bad lifter. I just redid all lifters, rocker arms and pushrods..all 4 angry squirrels working as intended. Pulled the valve cover and it was THICK with gunk..i mean BAD BAD. Dropped the oil pan and removed the lifters and cleaned and scrubbed for a day or so. Threw it all back together with new gaskets and fresh oil and its running pretty good as of now. Thanks to everyone for the advice and replies to help with this issue. Added a pic of the headache in question, much more stuff to do.

 

[DOWNS]

Good deal man. Glad you got it figured out.

 

[T-Rex Jeepster]

UPDATE

ended up being a bad lifter. I just redid all lifters, rocker arms and pushrods..all 4 angry squirrels working as intended. Pulled the valve cover and it was THICK with gunk..i mean BAD BAD. Dropped the oil pan and removed the lifters and cleaned and scrubbed for a day or so. Threw it all back together with new gaskets and fresh oil and its running pretty good as of now. Thanks to everyone for the advice and replies to help with this issue. Added a pic of the headache in question, much more stuff to do.

View attachment 121803

I recommend using this stiction eliminator for deep cleaning the innards of your 2.5...I used it on my '94 4.0 and it worked very well. Has micro lubing additive as well. Just dump the whole quart in.

 

[T-Rex Jeepster]

It idles ok now, but about 2k rpms it sputters and pops/crackles like crazy
View attachment 121694

Had the same problem, Replaced the distributor and that straightened it right out.