Loss of power

Sam Tallent

New Member
Joined
Jun 18, 2022
Messages
8
Location
Friendsville tn
Have a 95 yj 4.0 having issues with power ,it will idle good sometimes rpm will go up and down but when you put a load on it it falls on it's face. I have changed 6 injectors 4 hole, throttle position sensor, throttle idle sensor, air intake temp sensor, coolant temp sensor, map sensor, 02 sensor, plugs, wires, dist cap, rotor button, fuel filter, fuel pump, fuel pressure regulator, crankshaft position sensor and it still having issues. This all of sudden happened. Plz help.
 

Stoopid Jeep

YJ Enthusiast
Joined
Dec 25, 2021
Messages
159
Location
North Idaho
**more information needed

Are you showing any codes?

What is your fuel pressure when the incident happens.

is there a "miss or a studder" when it looses power?
 
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Sam Tallent

Sam Tallent

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Joined
Jun 18, 2022
Messages
8
Location
Friendsville tn
I run smoke thru the engine no leaks. I changed both ccv elbows on valve cover. I also check all the sensors connector before I changed them all good. I ordered a camshaft position sensor that goes in the distributor hope this solve the issue.
 

Stoopid Jeep

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Dec 25, 2021
Messages
159
Location
North Idaho
I run smoke thru the engine no leaks. I changed both ccv elbows on valve cover. I also check all the sensors connector before I changed them all good. I ordered a camshaft position sensor that goes in the distributor hope this solve the issue.
A bad cam position sensor [should] throw a code. You stated there are no codes present.
When you flash the codes, there are literally no codes? Are you at least getting code 55?
 

redbullet

YJ Enthusiast
Joined
May 11, 2021
Messages
102
Location
San Jose, CA
Remove the O2 sensor from the hole and detach it (so it does not get tangled up on the front drive shaft)…go for a drive and see if the problem is there. If it goes away while sensor is disconnected you could have a clogged cat and/or exhaust
 
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Sam Tallent

Sam Tallent

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Joined
Jun 18, 2022
Messages
8
Location
Friendsville tn
Remove the O2 sensor from the hole and detach it (so it does not get tangled up on the front drive shaft)…go for a drive and see if the problem is there. If it goes away while sensor is disconnected you could have a clogged cat and/or exhaust
It doesn't change plus it is new I have a header straight pipe to a magna flow.
 

Stoopid Jeep

YJ Enthusiast
Joined
Dec 25, 2021
Messages
159
Location
North Idaho
Yes that is battery disconnect
Code 55 is "Completion of trouble code display"
code 12 is "Battery Disconnect"
code 33 is "A/C Clutch Relay Circuit" (you will get this code if your vehicle doesn't have AC)

Have you done a compression test?
Have you inspected all of your ignition components? plugs, wires, cap rotor.
Have you inspected all of the old flexible fuel line coming out of the tank and at the fuel filter?
Did you get some bad gas? (it happens)

Just trying to rule out all the simple stuff.
 

JKP

New Member
Joined
Feb 20, 2021
Messages
23
Location
Warner Robins GA
Have a 95 yj 4.0 having issues with power ,it will idle good sometimes rpm will go up and down but when you put a load on it it falls on it's face. I have changed 6 injectors 4 hole, throttle position sensor, throttle idle sensor, air intake temp sensor, coolant temp sensor, map sensor, 02 sensor, plugs, wires, dist cap, rotor button, fuel filter, fuel pump, fuel pressure regulator, crankshaft position sensor and it still having issues. This all of sudden happened. Plz help.
I'm going with coil. A weak spark will not ignite the rich mixture that comes with loading it down.

The only non China coil that I found for my '92 was a Blue Streak by Standard Ignition. Even the MOPAR ones are from China now and only last a yr or two. Auto parts store brands lasted weeks to months. So far the Blue Streak is still going.
 
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Sam Tallent

Sam Tallent

New Member
Joined
Jun 18, 2022
Messages
8
Location
Friendsville tn
Code 55 is "Completion of trouble code display"
code 12 is "Battery Disconnect"
code 33 is "A/C Clutch Relay Circuit" (you will get this code if your vehicle doesn't have AC)

Have you done a compression test?
Have you inspected all of your ignition components? plugs, wires, cap rotor.
Have you inspected all of the old flexible fuel line coming out of the tank and at the fuel filter?
Did you get some bad gas? (it happens)

Just trying to rule out all the simple stuff.
When I changed fuel pump I put new lines all the way back to front. As listed from first post I did all the sensors plugs wires cap rotor button. Also when I had the fuel pump out I drained all gas got rid of it and cleaned the tank out. I know your trying thanks .
 
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Sam Tallent

Sam Tallent

New Member
Joined
Jun 18, 2022
Messages
8
Location
Friendsville tn
I'm going with coil. A weak spark will not ignite the rich mixture that comes with loading it down.

The only non China coil that I found for my '92 was a Blue Streak by Standard Ignition. Even the MOPAR ones are from China now and only last a yr or two. Auto parts store brands lasted weeks to months. So far the Blue Streak is still going.
I have not changed that . With all I have changed I guess I can change it too lol.
 

Jpuga

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Supporting Member
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Jun 17, 2022
Messages
7
Location
Delano
Try removing the throttle body and remove the sensors from it and give it a good cleaning with some chemtool. Make sure the ports to the sensors are clean. Might need a gasket for the throttle body.