Debating on Jeeps
#16
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Hold the stud still with a reverse Torx and remove the nut with a 1/2" wrench. This could very well be a major issue. Fix it.
#17
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Year: 1987
Model: Cherokee(XJ)
Engine: 4.0
Ok, so today I did steps 1-5. The only thing i wasn't able to do was change the braided ground wire with a #4 gauge wire. Other than that everything went great. I'm still having problems with it even after doing all those steps but I am getting better readings on the battery gauge on the dash cluster. I am not sure if that would get affected with what i did, but i am clearly getting a better reading.
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Year: 1987
Model: Cherokee(XJ)
Engine: 4.0
I also took the oil cap off the top of the valve cover and smelled it and it smelled like oil and gas mixed together. I think one of the injectors is either not working at all or completely stuck open
#20
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Year: 1990
Model: Cherokee (XJ)
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Swapping out to Volvo 746 injectors is always a good idea. jhc7399 here on cF has them refurbished at a very reasonable price.
#21
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Year: 1991
Model: Cherokee(XJ)
Engine: 4.0L
Not technical advice, but as to whether or not you should keep it and keep fixing it, I would say yes. Of course that depends on your own situation and what your "huge list of problems" is. But many years ago I got rid of my 1989 with 250K miles on it when it started having a lot of problems. I didn't want to spend the time and money on it at the time so I sold it. I regretted it ever since. That 1989 was pretty easy to work on and I knew it well. Good XJ are harder and harder to find. I love my 1991 XJ but I often miss my old 1989. I really had it dialed into my tastes and when I have to replace things like electric window regulators and watch my transmission temp I really miss my hand crank windows and my five speed manual transmission. Depending on your financial situation it may well be worth the time and money to keep it and fix it as you go.
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Year: 1987
Model: Cherokee(XJ)
Engine: 4.0
Well yesterday my injectors came in and today i put them in. I cleaned everything that was located around them, I cleaned the injector holes on the engine and i tried my best to be very thorough with everything. I turned the Jeep on and it runs AMAZING!!! I've never heard it run this nice and quiet.
Needless to say i'm definitely going to keep this jeep and its definitely going to be my off-road project Jeep. i just wanted to say thank you to everyone that has helped me on this thread, if it wasn't for y'all i probably wouldn't be in the same boat that i am now.
Needless to say i'm definitely going to keep this jeep and its definitely going to be my off-road project Jeep. i just wanted to say thank you to everyone that has helped me on this thread, if it wasn't for y'all i probably wouldn't be in the same boat that i am now.
#23
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Well yesterday my injectors came in and today i put them in. I cleaned everything that was located around them, I cleaned the injector holes on the engine and i tried my best to be very thorough with everything. I turned the Jeep on and it runs AMAZING!!! I've never heard it run this nice and quiet.
Needless to say i'm definitely going to keep this jeep and its definitely going to be my off-road project Jeep. i just wanted to say thank you to everyone that has helped me on this thread, if it wasn't for y'all i probably wouldn't be in the same boat that i am now.
Needless to say i'm definitely going to keep this jeep and its definitely going to be my off-road project Jeep. i just wanted to say thank you to everyone that has helped me on this thread, if it wasn't for y'all i probably wouldn't be in the same boat that i am now.
Great news.
#24
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Don't.
It's the wrong thing to do.
Certainly a new 4 gauge wire will do a better job there than a corroded mess of a braided wire, but a new braided wire will do better than 4 gauge.
That ground strap there is ONLY there to reduce radiofrequency noise. It's not intended as a ground path the same way your other ground wires are. It's not intended to carry any appreciable current.
If it ever does, you have major problems elsewhere. You really don't want much current flowing there, nor even the possibility of it.
Let's think about where current flowing through that strap or wire would go. It's flowing from the engine block, through the firewall ground strap to the body, through the body, back to your fenderwell ground point, through that cable to the battery terminal.
What current would flow through the block? If you have injectors, that's one source (and a big source of radiofrequncy noise). Spark plugs. Oooh, another source of radio noise. And then, your sensors. Not a big source of radio noise. None of these are sources of large amounts of current.
If your battery to fenderwell connection is not good, no matter what your firewall ground is doing, that path isn't going to carry the current well, so fix your fender ground before you do anything else.
But what other sources of current could there be flowing through the block?
Starter. Now we are talking about some serious current.
"Wait a minute, Mark! The starter current should flow through the big ground cable that goes from the battery terminal to the block!"
Yes, it should and it will. Unless....
Unless there is some corrosion or similar problem with that ground cable. If there is, and you crank your engine, that current will look for another path. Remember that big fat #4 cable you installed to the firewall? Yeah, a bunch of current is going to try to board that train. That means you will have a large current trying to flow through your fenderwell ground, which isn't capable of carrying it. That becomes an electrical choke point, a resistance. That's going to raise the electrical potential in the body above ground, so now all of your electrical circuits are experiencing a low voltage situation. This is what is known as, "undesirable operation".
What if you have the standard braided strap? Then the braided strap will be the choke point, probably burning out, and everything will stop.
This is a GOOD thing. The braided strap has acted like a fuse, preventing more serious problems.
Besides, the braided strap is better at its intended purpose than a 4 gauge wire, or even a 1 gauge wire.
Why?
Skin effect.
With direct current, electrical current travels though a conductor much like water flows through a pipe. It uses the full cross section of the conductor. At higher frequencies, current travels on the surface of a conductor. So, at high frequencies (like radio noise) more surface area, better conductor.
The braided strap, with all its many fine strands, has more surface area than the 4 gauge wire.
If your big battery-to-block cable is in good shape, that 4 gauge wire will never cause any problems. But it won't work better than the strap. (Though if you use a high quality fine-stranded marine cable, it might be equal.)
If doing that cures any problems, you had ground problems elsewhere that you missed, and which still need to be fixed.
I don't expect to ever know a tenth of what Cruiser knows abut Jeeps.
But on this one, he's mistaken. The braid is what you want, not a 4 gauge cable.
Last edited by BlueRidgeMark; 03-31-2018 at 08:41 PM.
#25
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Don't.
It's the wrong thing to do.
Certainly a new 4 gauge wire will do a better job there than a corroded mess of a braided wire, but a new braided wire will do better than 4 gauge.
That ground strap there is ONLY there to reduce radiofrequency noise. It's not intended as a ground path the same way your other ground wires are. It's not intended to carry any appreciable current.
If it ever does, you have major problems elsewhere. You really don't want much current flowing there, nor even the possibility of it.
Let's think about where current flowing through that strap or wire would go. It's flowing from the engine block, through the firewall ground strap to the body, through the body, back to your fenderwell ground point, through that cable to the battery terminal.
What current would flow through the block? If you have injectors, that's one source (and a big source of radiofrequncy noise). Spark plugs. Oooh, another source of radio noise. And then, your sensors. Not a big source of radio noise. None of these are sources of large amounts of current.
If your battery to fenderwell connection is not good, no matter what your firewall ground is doing, that path isn't going to carry the current well, so fix your fender ground before you do anything else.
But what other sources of current could there be flowing through the block?
Starter. Now we are talking about some serious current.
"Wait a minute, Mark! The starter current should flow through the big ground cable that goes from the battery terminal to the block!"
Yes, it should and it will. Unless....
Unless there is some corrosion or similar problem with that ground cable. If there is, and you crank your engine, that current will look for another path. Remember that big fat #4 cable you installed to the firewall? Yeah, a bunch of current is going to try to board that train. That means you will have a large current trying to flow through your fenderwell ground, which isn't capable of carrying it. That becomes an electrical choke point, a resistance. That's going to raise the electrical potential in the body above ground, so now all of your electrical circuits are experiencing a low voltage situation. This is what is known as, "undesirable operation".
What if you have the standard braided strap? Then the braided strap will be the choke point, probably burning out, and everything will stop.
This is a GOOD thing. The braided strap has acted like a fuse, preventing more serious problems.
Besides, the braided strap is better at its intended purpose than a 4 gauge wire, or even a 1 gauge wire.
Why?
Skin effect.
With direct current, electrical current travels though a conductor much like water flows through a pipe. It uses the full cross section of the conductor. At higher frequencies, current travels on the surface of a conductor. So, at high frequencies (like radio noise) more surface area, better conductor.
The braided strap, with all its many fine strands, has more surface area than the 4 gauge wire.
If your big battery-to-block cable is in good shape, that 4 gauge wire will never cause any problems. But it won't work better than the strap. (Though if you use a high quality fine-stranded marine cable, it might be equal.)
If doing that cures any problems, you had ground problems elsewhere that you missed, and which still need to be fixed.
I don't expect to ever know a tenth of what Cruiser knows abut Jeeps.
But on this one, he's mistaken. The braid is what you want, not a 4 gauge cable.
It's the wrong thing to do.
Certainly a new 4 gauge wire will do a better job there than a corroded mess of a braided wire, but a new braided wire will do better than 4 gauge.
That ground strap there is ONLY there to reduce radiofrequency noise. It's not intended as a ground path the same way your other ground wires are. It's not intended to carry any appreciable current.
If it ever does, you have major problems elsewhere. You really don't want much current flowing there, nor even the possibility of it.
Let's think about where current flowing through that strap or wire would go. It's flowing from the engine block, through the firewall ground strap to the body, through the body, back to your fenderwell ground point, through that cable to the battery terminal.
What current would flow through the block? If you have injectors, that's one source (and a big source of radiofrequncy noise). Spark plugs. Oooh, another source of radio noise. And then, your sensors. Not a big source of radio noise. None of these are sources of large amounts of current.
If your battery to fenderwell connection is not good, no matter what your firewall ground is doing, that path isn't going to carry the current well, so fix your fender ground before you do anything else.
But what other sources of current could there be flowing through the block?
Starter. Now we are talking about some serious current.
"Wait a minute, Mark! The starter current should flow through the big ground cable that goes from the battery terminal to the block!"
Yes, it should and it will. Unless....
Unless there is some corrosion or similar problem with that ground cable. If there is, and you crank your engine, that current will look for another path. Remember that big fat #4 cable you installed to the firewall? Yeah, a bunch of current is going to try to board that train. That means you will have a large current trying to flow through your fenderwell ground, which isn't capable of carrying it. That becomes an electrical choke point, a resistance. That's going to raise the electrical potential in the body above ground, so now all of your electrical circuits are experiencing a low voltage situation. This is what is known as, "undesirable operation".
What if you have the standard braided strap? Then the braided strap will be the choke point, probably burning out, and everything will stop.
This is a GOOD thing. The braided strap has acted like a fuse, preventing more serious problems.
Besides, the braided strap is better at its intended purpose than a 4 gauge wire, or even a 1 gauge wire.
Why?
Skin effect.
With direct current, electrical current travels though a conductor much like water flows through a pipe. It uses the full cross section of the conductor. At higher frequencies, current travels on the surface of a conductor. So, at high frequencies (like radio noise) more surface area, better conductor.
The braided strap, with all its many fine strands, has more surface area than the 4 gauge wire.
If your big battery-to-block cable is in good shape, that 4 gauge wire will never cause any problems. But it won't work better than the strap. (Though if you use a high quality fine-stranded marine cable, it might be equal.)
If doing that cures any problems, you had ground problems elsewhere that you missed, and which still need to be fixed.
I don't expect to ever know a tenth of what Cruiser knows abut Jeeps.
But on this one, he's mistaken. The braid is what you want, not a 4 gauge cable.
Not on Renix.
#26
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
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Engine: 4.0
Does Renix not start life with a braided strap to the firewall? Does Renix not have a large ground cable from the battery to the block?
#27
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Year: 1990
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And, the field engineers realized the strap wasn't cutting the mustard.
It made poor contact with the firewall and was subject to corrosion in the harsher environments.
I don't think it was ever addressed in a TSB, but the guys in JeepTech told me about it. It's in "The book"
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