Neon injector upgrade
Thread Starter
Seasoned Member
Joined: Dec 2011
Posts: 319
Likes: 0
From: Wenatchee, WA
Year: 1990
Model: Cherokee
Engine: 4.0L Renix
My 90 works fine with the 703's. It's just a little rich, and the renix ECU....doesn't reset, has no memory. You may well just have a normal problem. Plugs OK? MAP tube, cap/rotor wires, vac leak.... I might check those basics....bad gas...
Here's notop's thread.. https://www.cherokeeforum.com/f2/10-...08854/index10/
Thought you might want to see it if you have 703's in your renix.
Here's notop's thread.. https://www.cherokeeforum.com/f2/10-...08854/index10/
Thought you might want to see it if you have 703's in your renix.
UGH! Yea...there is no way I am keeping these injectors if it stays running like this.
Thread Starter
Seasoned Member
Joined: Dec 2011
Posts: 319
Likes: 0
From: Wenatchee, WA
Year: 1990
Model: Cherokee
Engine: 4.0L Renix
I'm considering putting my old injectors back in tomorrow and selling these 703's and getting those 3.7L V6 Jeep Liberty injectors....
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
On the liberty injectors...I don't mean to come off like i know much, just a few things. 87-90 renix is not gonna "learn" or "reset". It uses injectors that deliver 18.6 Lbs/Hr. (I guess they use a standard test pressure for that). If ,say 22 Lbs/Hr, comes along it will run rich. The 02 will try to lean it out. I suppose on 91 on maybe it can, but it's looking like our old renix.....is gonna end up rich. So if I went there (again) I'd be looking at that flow rate.
Maybe I'm dead wrong. Maybe my 02 is not up to snuff. My mileage deafeningly, no doubt went down with the 703's. Still, I should make sure my 02 sensor is up to snuff.
Sounds like your guy cleaned and checked them, but still maybe there is some problem. Maybe something got into the lines or injector(s) while they were of? They should work. Besides Freedgr and myself, others are runnen them.
Maybe you got a lower O ring out of joint when you installed them, or picked up another vacuum leak somewhere. Takes two minutes to rule out a vacuum leak with a $2 can of Starting fluid. A DAB WILL DO YOU A short little shot or two, then let it evaporate. Go around. The sound of the engine will change when you hit it. Short shot's Don't hose it down and get it all over. Of course a fire extinguisher sometimes seems pretty handy. Don't set the can down on the battery.
Or listen with a length of hose to your ear.
Also you might look at the wiring to the sensors below your manifold, especially where it goes around and down, and also at the 02. Mine shorted on the heat shield, plenty of others have posted that their 02 wires where melted.
Then there's this;
That rear manifold bolt has a habit of loosening. On anything like that you NEVER want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. Go over three times, a tad tighter each time. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension(s). For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep.
Don't let having the 703's divert you. Magicians use that all the time! (so you don't see what really happened).
I guess you checked. That little Map tube from the inside of the TB, up to the map. You didn't breath on that while changing your injectors? Mine was brittle and fell apart. It would run somewhat like you describe if its cracked, off, or plugged. Very important that the Map get's good vacuum.
Maybe I'm dead wrong. Maybe my 02 is not up to snuff. My mileage deafeningly, no doubt went down with the 703's. Still, I should make sure my 02 sensor is up to snuff.
Sounds like your guy cleaned and checked them, but still maybe there is some problem. Maybe something got into the lines or injector(s) while they were of? They should work. Besides Freedgr and myself, others are runnen them.
Maybe you got a lower O ring out of joint when you installed them, or picked up another vacuum leak somewhere. Takes two minutes to rule out a vacuum leak with a $2 can of Starting fluid. A DAB WILL DO YOU A short little shot or two, then let it evaporate. Go around. The sound of the engine will change when you hit it. Short shot's Don't hose it down and get it all over. Of course a fire extinguisher sometimes seems pretty handy. Don't set the can down on the battery.
Or listen with a length of hose to your ear.
Also you might look at the wiring to the sensors below your manifold, especially where it goes around and down, and also at the 02. Mine shorted on the heat shield, plenty of others have posted that their 02 wires where melted.
Then there's this;
That rear manifold bolt has a habit of loosening. On anything like that you NEVER want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. Go over three times, a tad tighter each time. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension(s). For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep.
Don't let having the 703's divert you. Magicians use that all the time! (so you don't see what really happened).
I guess you checked. That little Map tube from the inside of the TB, up to the map. You didn't breath on that while changing your injectors? Mine was brittle and fell apart. It would run somewhat like you describe if its cracked, off, or plugged. Very important that the Map get's good vacuum.
Last edited by DFlintstone; Apr 11, 2012 at 04:24 PM. Reason: is
CF Veteran
Joined: Nov 2011
Posts: 2,381
Likes: 6
From: SoCal
Year: 1989
Model: Cherokee
Engine: 4.0
On the liberty injectors...I don't mean to come off like i know much, just a few things. 87-90 renix is not gonna "learn" or "reset". It uses injectors that deliver 18.6 Lbs/Hr. (I guess they use a standard test pressure for that). If ,say 22 Lbs/Hr, comes along it will run rich. The 02 will try to lean it out. I suppose on 91 on maybe it can, but it's looking like our old renix.....is gonna end up rich. So if I went there (again) I'd be looking at that flow rate.
Maybe I'm dead wrong. Maybe my 02 is not up to snuff. My mileage deafeningly, no doubt went down with the 703's. Still, I should make sure my 02 sensor it up to snuff.
Sounds like your guy cleaned and checked them, but still maybe there is some problem. Maybe something got into the lines or injector(s) while they were of? They should work. Besides Freedgr and myself, others are runnen them.
Maybe you got a lower O ring out of joint when you installed them, or picked up another vacuum leak somewhere. Takes two minutes to rule out a vacuum leak with a $2 can of Starting fluid. A DAB WILL DO YOU A short little shot or two, then let it evaporate. Go around. The sound of the engine will change when you hit it. Short shot's Don't hose it down and get it all over. Of course a fire extinguisher sometimes seems pretty handy. Don't set the can down on the battery.
Or listen with a length of hose to your ear.
Also you might look at the wiring to the sensors below your manifold, especially where it goes around and down, and also at the 02. Mine shorted on the heat shield, plenty of others have posted that their 02 wires where melted.
Then there's this;
That rear manifold bolt has a habit of loosening. On anything like that you NEVER want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. Go over three times, a tad tighter each time. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension(s). For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep.
Don't let having the 703's divert you. Magicians use that all the time! (so you don't see what really happened).
Maybe I'm dead wrong. Maybe my 02 is not up to snuff. My mileage deafeningly, no doubt went down with the 703's. Still, I should make sure my 02 sensor it up to snuff.
Sounds like your guy cleaned and checked them, but still maybe there is some problem. Maybe something got into the lines or injector(s) while they were of? They should work. Besides Freedgr and myself, others are runnen them.
Maybe you got a lower O ring out of joint when you installed them, or picked up another vacuum leak somewhere. Takes two minutes to rule out a vacuum leak with a $2 can of Starting fluid. A DAB WILL DO YOU A short little shot or two, then let it evaporate. Go around. The sound of the engine will change when you hit it. Short shot's Don't hose it down and get it all over. Of course a fire extinguisher sometimes seems pretty handy. Don't set the can down on the battery.
Or listen with a length of hose to your ear.
Also you might look at the wiring to the sensors below your manifold, especially where it goes around and down, and also at the 02. Mine shorted on the heat shield, plenty of others have posted that their 02 wires where melted.
Then there's this;
That rear manifold bolt has a habit of loosening. On anything like that you NEVER want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. Go over three times, a tad tighter each time. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension(s). For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep.
Don't let having the 703's divert you. Magicians use that all the time! (so you don't see what really happened).
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
No, where I am you only need to smog when you first register. From what I'm having I'd have to say no. If you are getting 16+ I'd take it in like that. Won't they let you work on it and try again if you don't pass? (high HC). You might have a little leak that keeps it from holding pressure, but isn't sooo important running. You might run some cleaner through, also see what wiser minds have to say.
I've been putting off trying this 02 sensor test. Maybe it's my problem
, or part of it.
http://www.naxja.org/forum/showthrea...ht=sensor+test
I've been putting off trying this 02 sensor test. Maybe it's my problem
, or part of it.
http://www.naxja.org/forum/showthrea...ht=sensor+test
Thread Starter
Seasoned Member
Joined: Dec 2011
Posts: 319
Likes: 0
From: Wenatchee, WA
Year: 1990
Model: Cherokee
Engine: 4.0L Renix
On the liberty injectors...I don't mean to come off like i know much, just a few things. 87-90 renix is not gonna "learn" or "reset". It uses injectors that deliver 18.6 Lbs/Hr. (I guess they use a standard test pressure for that). If ,say 22 Lbs/Hr, comes along it will run rich. The 02 will try to lean it out. I suppose on 91 on maybe it can, but it's looking like our old renix.....is gonna end up rich. So if I went there (again) I'd be looking at that flow rate.
Maybe I'm dead wrong. Maybe my 02 is not up to snuff. My mileage deafeningly, no doubt went down with the 703's. Still, I should make sure my 02 sensor it up to snuff.
Sounds like your guy cleaned and checked them, but still maybe there is some problem. Maybe something got into the lines or injector(s) while they were of? They should work. Besides Freedgr and myself, others are runnen them.
Maybe you got a lower O ring out of joint when you installed them, or picked up another vacuum leak somewhere. Takes two minutes to rule out a vacuum leak with a $2 can of Starting fluid. A DAB WILL DO YOU A short little shot or two, then let it evaporate. Go around. The sound of the engine will change when you hit it. Short shot's Don't hose it down and get it all over. Of course a fire extinguisher sometimes seems pretty handy. Don't set the can down on the battery.
Or listen with a length of hose to your ear.
Also you might look at the wiring to the sensors below your manifold, especially where it goes around and down, and also at the 02. Mine shorted on the heat shield, plenty of others have posted that their 02 wires where melted.
Then there's this;
That rear manifold bolt has a habit of loosening. On anything like that you NEVER want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. Go over three times, a tad tighter each time. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension(s). For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep.
Don't let having the 703's divert you. Magicians use that all the time! (so you don't see what really happened).
I guess you checked. That little Map tube from the inside of the TB, up to the map. You didn't breath on that while changing your injectors? Mine was brittle and fell apart. It would run somewhat like you describe if its cracked, off, or plugged. Very important that the Map get's good vacuum.
Maybe I'm dead wrong. Maybe my 02 is not up to snuff. My mileage deafeningly, no doubt went down with the 703's. Still, I should make sure my 02 sensor it up to snuff.
Sounds like your guy cleaned and checked them, but still maybe there is some problem. Maybe something got into the lines or injector(s) while they were of? They should work. Besides Freedgr and myself, others are runnen them.
Maybe you got a lower O ring out of joint when you installed them, or picked up another vacuum leak somewhere. Takes two minutes to rule out a vacuum leak with a $2 can of Starting fluid. A DAB WILL DO YOU A short little shot or two, then let it evaporate. Go around. The sound of the engine will change when you hit it. Short shot's Don't hose it down and get it all over. Of course a fire extinguisher sometimes seems pretty handy. Don't set the can down on the battery.
Or listen with a length of hose to your ear.
Also you might look at the wiring to the sensors below your manifold, especially where it goes around and down, and also at the 02. Mine shorted on the heat shield, plenty of others have posted that their 02 wires where melted.
Then there's this;
That rear manifold bolt has a habit of loosening. On anything like that you NEVER want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. Go over three times, a tad tighter each time. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension(s). For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep.
Don't let having the 703's divert you. Magicians use that all the time! (so you don't see what really happened).
I guess you checked. That little Map tube from the inside of the TB, up to the map. You didn't breath on that while changing your injectors? Mine was brittle and fell apart. It would run somewhat like you describe if its cracked, off, or plugged. Very important that the Map get's good vacuum.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
And the crowd cheers!!
Well done!I guess the good news that that tube might last 20 years.
I guess the bad news is that tube might just last 20 years.
I had trouble with a little stub broken off in the rubber plug in the TB. Got clever and used a tiny extractor I had. Then realized a screw would work fine, don't need reverse thread.
I hear any manifold vacuum is fine. Not sure why the special business on the TB.
Thread Starter
Seasoned Member
Joined: Dec 2011
Posts: 319
Likes: 0
From: Wenatchee, WA
Year: 1990
Model: Cherokee
Engine: 4.0L Renix
And the crowd cheers!! Well done!
I guess the good news that that tube might last 20 years.
I guess the bad news is that tube might just last 20 years.
I had trouble with a little stub broken off in the rubber plug in the TB. Got clever and used a tiny extractor I had. Then realized a screw would work fine, don't need reverse thread.
I hear any manifold vacuum is fine. Not sure why the special business on the TB.
Well done!I guess the good news that that tube might last 20 years.
I guess the bad news is that tube might just last 20 years.
I had trouble with a little stub broken off in the rubber plug in the TB. Got clever and used a tiny extractor I had. Then realized a screw would work fine, don't need reverse thread.
I hear any manifold vacuum is fine. Not sure why the special business on the TB.
CF Veteran
Joined: Nov 2011
Posts: 2,381
Likes: 6
From: SoCal
Year: 1989
Model: Cherokee
Engine: 4.0
No, where I am you only need to smog when you first register. From what I'm having I'd have to say no. If you are getting 16+ I'd take it in like that. Won't they let you work on it and try again if you don't pass? (high HC). You might have a little leak that keeps it from holding pressure, but isn't sooo important running. You might run some cleaner through, also see what wiser minds have to say.[/url]
When I discovered that it was leaking again (while repairing a fried spark plug wire) I decided it was time to upgrade and spent Monday and Tuesday scavenging my local junkyards for 703 injectors. I'll wait to hear back from ShootingSticks as to whether or not replacing the vacuum line to his MAP remedied the rich condition he was experiencing before I start wracking my brain for alternate solutions. I could probably install the 703s and deal with the rich mixture and swap the stock injectors back in for smog but if the 703s foul my catalytic converters then I don't see how I've gained anything.
CF Veteran
Joined: Nov 2011
Posts: 2,381
Likes: 6
From: SoCal
Year: 1989
Model: Cherokee
Engine: 4.0
I'm guessing that the beer drinking smilie posted by shooting sticks means that all is right in XJ land so I'll move forward with the injector swap and keep my fingers crossed.
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
I pulled the rail and cleaned my stock injectors thoroughly a few months ago and, at the same time, epoxied (chem-resistant) the body of the injector where it was leaking which I knew wasn't a permanent solution but it worked long enough for me to take care of more pressing issues. The leak is substantial enough that I can see gas bubbling around the seam where plastic meets metal, I can also see an area on the heat shield where gas has pooled. In California, we also have to pass a visual inspection and if raw gasoline is present in the engine bay they will not pass it.
When I discovered that it was leaking again (while repairing a fried spark plug wire) I decided it was time to upgrade and spent Monday and Tuesday scavenging my local junkyards for 703 injectors. I'll wait to hear back from ShootingSticks as to whether or not replacing the vacuum line to his MAP remedied the rich condition he was experiencing before I start wracking my brain for alternate solutions. I could probably install the 703s and deal with the rich mixture and swap the stock injectors back in for smog but if the 703s foul my catalytic converters then I don't see how I've gained anything.
When I discovered that it was leaking again (while repairing a fried spark plug wire) I decided it was time to upgrade and spent Monday and Tuesday scavenging my local junkyards for 703 injectors. I'll wait to hear back from ShootingSticks as to whether or not replacing the vacuum line to his MAP remedied the rich condition he was experiencing before I start wracking my brain for alternate solutions. I could probably install the 703s and deal with the rich mixture and swap the stock injectors back in for smog but if the 703s foul my catalytic converters then I don't see how I've gained anything.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Oh! leaking on the outside. The you have those. Yea, they will crumble like a MAP tube if you mess with them. Boy, Idk. Don't think there is any issue with f*** up your converter. Mine just seems a little rich. Like two MPG, 17 hyway instead of 19, 11-12 knocking around instead if 13-14. If you just tried to change out one of the crap deka-simmons or whatever, more may well end up leaking.
Maybe install the 703's, march in there, and then report back to us if they ever let you go...Sounds like shooting stix is OK.
I'm in CA as well btw, just not in a "smog control district"
Maybe install the 703's, march in there, and then report back to us if they ever let you go...Sounds like shooting stix is OK.
I'm in CA as well btw, just not in a "smog control district"
CF Veteran
Joined: Nov 2011
Posts: 2,381
Likes: 6
From: SoCal
Year: 1989
Model: Cherokee
Engine: 4.0
