I Need Help with Really Rough Shaking Start

[QuinnD]

Okay, I have a 2000 Jeep Cherokee XJ and have been trying to solve this issue for the last couple months.
My car has had a severe, rough, violently shaking that happens when I start it up (only occasionally) and it throws NO MISFIRE CODES.
I have
- changed out the bank 2 o2 sensor (was throwing code)
- replaced ignition rail and spark plugs
- done a compression test which came out fine
I have a very difficult ground terminal that can be intermittent
The shaking happens randomly when starting (hot or cold) and while driving and does NOT THROW any codes
The only times i get misfire codes are when my car is driving smooth which is weird.

I'm at my wits end here and really wanted to make this car overland capable. HELP

 

[danwyandt]

Okay, I have a 2000 Jeep Cherokee XJ and have been trying to solve this issue for the last couple months.
My car has had a severe, rough, violently shaking that happens when I start it up (only occasionally) and it throws NO MISFIRE CODES.
I have
- changed out the bank 2 o2 sensor (was throwing code)
- replaced ignition rail and spark plugs
- done a compression test which came out fine
I have a very difficult ground terminal that can be intermittent
The shaking happens randomly when starting (hot or cold) and while driving and does NOT THROW any codes
The only times i get misfire codes are when my car is driving smooth which is weird.

I'm at my wits end here and really wanted to make this car overland capable. HELP

Not a jeep owner, but I would go after the easy stuff first.

* idle air control valve and gasket

* TPS, check reference voltage at closed and WOT

* Clean the throttle body.

It might be worthwhile if you don't have an engine diagnostic scanner to get to a shop?

 

[QuinnD]

Okay, I have a 2000 Jeep Cherokee XJ and have been trying to solve this issue for the last couple months.
My car has had a severe, rough, violently shaking that happens when I start it up (only occasionally) and it throws NO MISFIRE CODES.
I have
- changed out the bank 2 o2 sensor (was throwing code)
- replaced ignition rail and spark plugs
- done a compression test which came out fine
I have a very difficult ground terminal that can be intermittent
The shaking happens randomly when starting (hot or cold) and while driving and does NOT THROW any codes
The only times i get misfire codes are when my car is driving smooth which is weird.

I'm at my wits end here and really wanted to make this car overland capable. HELP

Not a jeep owner, but I would go after the easy stuff first.

* idle air control valve and gasket

* TPS, check reference voltage at closed and WOT

* Clean the throttle body.

It might be worthwhile if you don't have an engine diagnostic scanner to get to a shop?

Okay, I was also told by someone else to check tps and throttle body. However I was also told to check fuel pump, check valve, and fuel injectors. I might take it to a shop but I don’t want to just yet since I don’t have a great idea of what’s happening

 

[Cypress]

Change your injectors. My XJ did the same thing. It turned out it had an injector that was leaking raw fuel into the intake when the engine was off. I was at 260k miles so I replaced all of the injectors and that solved the problem.

 

[QuinnD]

Change your injectors. My XJ did the same thing. It turned out it had an injector that was leaking raw fuel into the intake when the engine was off. I was at 260k miles so I replaced all of the injectors and that solved the problem.

Okay, thank you. Just clarifying, did it do it while driving and when starting hot and cold. I’m planning on replacing all the injectors, just curious.

 

[Cypress]

Mostly warm starts. A hot start would usually sputter once or twice and run fine. If it sat for a few days it would usually crank normally. If you shut it down for 30 minutes to run in the grocery store it would fire on 3-4 cylinders until it cleared the extra fuel out of the intake. It started only doing that occasionally but progressively got worse. A good indicator is to check the fuel rail for pressure after it sits for an hour or so. If there is none then it's leaking somewhere.

 

[North American Sojourner]

Okay, I have a 2000 Jeep Cherokee XJ and have been trying to solve this issue for the last couple months.
My car has had a severe, rough, violently shaking that happens when I start it up (only occasionally) and it throws NO MISFIRE CODES.
I have
- changed out the bank 2 o2 sensor (was throwing code)
- replaced ignition rail and spark plugs
- done a compression test which came out fine
I have a very difficult ground terminal that can be intermittent
The shaking happens randomly when starting (hot or cold) and while driving and does NOT THROW any codes
The only times i get misfire codes are when my car is driving smooth which is weird.

I'm at my wits end here and really wanted to make this car overland capable. HELP

The suspect ground is a target. Find the ground, all of them and place a "snowflake" washer under them to improve "continuity"
There are a few, upwards of 13 or 15 on the car.

Next do a "torque test" on the engine mounts. Get a friend to hold the brake and push the gas at the same time and watch the engine and mounts to see what happens.
Does it move, shake, vibrate at different RPMs.

Finally what are you doing with the codes?
You said;
The only times i get misfire codes are when my car is driving smooth which is weird.
Are you deleting them?
Go to OReilly's and have them scan the truck and print out the codes. It will list them all. Don't pick and choose what others recommend. Get all of them and list them here and I'll take a look.
That's all I got.
Please deposit $376.44 into my paypal account. LOL
Zim





LMAO

 

[QuinnD]

Okay, I have a 2000 Jeep Cherokee XJ and have been trying to solve this issue for the last couple months.
My car has had a severe, rough, violently shaking that happens when I start it up (only occasionally) and it throws NO MISFIRE CODES.
I have
- changed out the bank 2 o2 sensor (was throwing code)
- replaced ignition rail and spark plugs
- done a compression test which came out fine
I have a very difficult ground terminal that can be intermittent
The shaking happens randomly when starting (hot or cold) and while driving and does NOT THROW any codes
The only times i get misfire codes are when my car is driving smooth which is weird.

I'm at my wits end here and really wanted to make this car overland capable. HELP

The suspect ground is a target. Find the ground, all of them and place a "snowflake" washer under them to improve "continuity"
There are a few, upwards of 13 or 15 on the car.

Next do a "torque test" on the engine mounts. Get a friend to hold the brake and push the gas at the same time and watch the engine and mounts to see what happens.
Does it move, shake, vibrate at different RPMs.

Finally what are you doing with the codes?
You said;
The only times i get misfire codes are when my car is driving smooth which is weird.
Are you deleting them?
Go to OReilly's and have them scan the truck and print out the codes. It will list them all. Don't pick and choose what others recommend. Get all of them and list them here and I'll take a look.
That's all I got.
Please deposit $376.44 into my paypal account. LOL
Zim

View attachment 275260

View attachment 275261

LMAO

Lmao, thank you for all the info, I have an OBD sensor so I just check the codes when they come in. I had a shop recently print out all my codes but they were what my sensor told me. I will try a torque test and for sure fix the ground. But I am suspecting some kind of fuel leaking into my engine.

 

[North American Sojourner]

Lmao, thank you for all the info, I have an OBD sensor so I just check the codes when they come in. I had a shop recently print out all my codes but they were what my sensor told me. I will try a torque test and for sure fix the ground. But I am suspecting some kind of fuel leaking into my engine.

LOL, love to have a fun talk. I've sold millions of dollars in parts, and only 3 injectors in 20 years. A good product is "Berryman's B12" Commonly available. Company is 100 years old. Try that in the tank.
But I'm thinking it's something else.
Zim

 

[QuinnD]

Lmao, thank you for all the info, I have an OBD sensor so I just check the codes when they come in. I had a shop recently print out all my codes but they were what my sensor told me. I will try a torque test and for sure fix the ground. But I am suspecting some kind of fuel leaking into my engine.

LOL, love to have a fun talk. I've sold millions of dollars in parts, and only 3 injectors in 20 years. A good product is "Berryman's B12" Commonly available. Company is 100 years old. Try that in the tank.
But I'm thinking it's something else.
Zim

Okay, I’ll try what you’re thinking. I’ve also been told that my fuel pump could be clogged. I’ll probably replace the fuel injectors just cus it’s time. It’s just a matter of getting to the bottom of whatever it is lmao ..ugh