87 Renix XJ with irritating intermittent miss
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Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
[quote=DFlintstone;2310251]
On decel, the injectors are shut off.
I think the warming up and the O2 sensor deal is a coincidence. If default was that rich, these things would never have passed the EPA test. /QUOTE]
Good point. Maybe that is what the hot air intake business is about. Idk, but point taken. Maybe they don't test it decelerating cold is my problem. We will see! If I see a 1-1/2 MPG improvement in my "knocken around" mileage I'll call that "statistically significant", and a win.
I have consecutive data on my last 35 fill-ups (or so). The seller showed 6 (746's) and used plural "injectors". He is not going to be to happy if he just ships one. He is in Oakland, where I spent some of my early years.
Good point. Maybe that is what the hot air intake business is about. Idk, but point taken. Maybe they don't test it decelerating cold is my problem. We will see! If I see a 1-1/2 MPG improvement in my "knocken around" mileage I'll call that "statistically significant", and a win.
I have consecutive data on my last 35 fill-ups (or so). The seller showed 6 (746's) and used plural "injectors". He is not going to be to happy if he just ships one. He is in Oakland, where I spent some of my early years.
On decel, the injectors are shut off.
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Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Do you remember above what RPM?
Here I just found "hard deceleration", which isisn't exactly what is happening at 35-40 in second. I swear I lost a Renix file somewhere. Thought I saw 25 or 2,600 RPM mentioned
Btw. My thanks again for pointing me toward the TCU wiring/switch to keep it in second. Makes my day better any day I'm going down my hill.
Here I just found "hard deceleration", which isisn't exactly what is happening at 35-40 in second. I swear I lost a Renix file somewhere. Thought I saw 25 or 2,600 RPM mentioned
Btw. My thanks again for pointing me toward the TCU wiring/switch to keep it in second. Makes my day better any day I'm going down my hill.
Last edited by DFlintstone; Feb 14, 2013 at 05:42 PM.
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Joined: Feb 2011
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From: Bergen County, New Jersey U.S.A.
Year: 1990 Laredo
Model: Cherokee
Engine: 4.0 Inline 6 Renix
I just learned something new on the decel thank you I get good 22 mpg on the regular with stockers and I have gotten 25 mpg on summer blend hm....
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Cool. I was not keeping good records 10 years, (100,000) miles ago. My mom's onicoligist was in Eugene OR (5 hrs north), and her treatments were at Davis, (8 hrs south) We did that a bunch...23-24 rings a bell...
Trivia, "South Park" was Springfield, Eugene's "sister city" on the Simpsons.
Yea, a stock 4wd (with functioning command track/(disco)) can clear 20 on the highway.
Trivia, "South Park" was Springfield, Eugene's "sister city" on the Simpsons.
Yea, a stock 4wd (with functioning command track/(disco)) can clear 20 on the highway.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Do you remember above what RPM?
Here I just found "hard deceleration", which isisn't exactly what is happening at 35-40 in second. I swear I lost a Renix file somewhere. Thought I saw 25 or 2,600 RPM mentioned
Btw. My thanks again for pointing me toward the TCU wiring/switch to keep it in second. Makes my day better any day I'm going down my hill.
Here I just found "hard deceleration", which isisn't exactly what is happening at 35-40 in second. I swear I lost a Renix file somewhere. Thought I saw 25 or 2,600 RPM mentioned
Btw. My thanks again for pointing me toward the TCU wiring/switch to keep it in second. Makes my day better any day I'm going down my hill.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I'll look some more...That's twice I swear I saw "operation's" in Renix manual I can't find now. The other was regarding the way it controls advance with the knock sensor. There I thought I read it will incrimently advance intill a knock signal, and here I saw a reference to I think , 2,600 rpm to cut injector power.(on decel) .....maybe adobe or foxit reader came back and took something back I was not suppose to take!
Last edited by DFlintstone; Feb 14, 2013 at 08:41 PM.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Cruiser loaned me his foil hat....really helps! 
Really frustrating. I'm no good at going through Mega bites of PDF files. I didn't make it up! I swear I saw a reference to what rpm the ECU shuts off fuel to the injectors on deceleration. academic I suppose, it was 25, or 2,600 RPM. Just spent an hour of a beautiful day looking, to no avail.
I maybe I'll look at where to put a meter on that just to see what mine is doing. (guess I could just "t" off one injector wire). Got no tack. I wonder if there is somewhere I can meter voltage to interpolate RPM.
Hey! Don't lambast me for getten "tecky" it IS OEM teck!
Really frustrating. I'm no good at going through Mega bites of PDF files. I didn't make it up! I swear I saw a reference to what rpm the ECU shuts off fuel to the injectors on deceleration. academic I suppose, it was 25, or 2,600 RPM. Just spent an hour of a beautiful day looking, to no avail.
I maybe I'll look at where to put a meter on that just to see what mine is doing. (guess I could just "t" off one injector wire). Got no tack. I wonder if there is somewhere I can meter voltage to interpolate RPM.
Hey! Don't lambast me for getten "tecky" it IS OEM teck!
Last edited by DFlintstone; Feb 15, 2013 at 04:01 PM.
CF Veteran
Joined: Feb 2011
Posts: 3,074
Likes: 0
From: Bergen County, New Jersey U.S.A.
Year: 1990 Laredo
Model: Cherokee
Engine: 4.0 Inline 6 Renix
Cruiser loaned me his foil hat....really helps!
Really frustrating. I'm no good at going through Mega bites of PDF files. I didn't make it up! I swear I saw a reference to what rpm the ECU shuts off fuel to the injectors on deceleration. academic I suppose, it was 25, or 2,600 RPM. Just spent an hour of a beautiful day looking, to no avail.
I maybe I'll look at where to put a meter on that just to see what mine is doing. (guess I could just "t" off one injector wire). Got no tack. I wonder if there is somewhere I can meter voltage to interpolate RPM.
Hey! Don't lambast me for getten "tecky" it IS OEM teck!
Really frustrating. I'm no good at going through Mega bites of PDF files. I didn't make it up! I swear I saw a reference to what rpm the ECU shuts off fuel to the injectors on deceleration. academic I suppose, it was 25, or 2,600 RPM. Just spent an hour of a beautiful day looking, to no avail.
I maybe I'll look at where to put a meter on that just to see what mine is doing. (guess I could just "t" off one injector wire). Got no tack. I wonder if there is somewhere I can meter voltage to interpolate RPM.
Hey! Don't lambast me for getten "tecky" it IS OEM teck!
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 33
Likes: 0
From: Tucson, AZ
Year: 1987
Model: Cherokee
Engine: 4.0
It's been a week so far since my jeep was filled up with chevron gas and it hasn't missed yet. I had to throw $20 in it a few days ago and I put $30 in it this morning on the way out to go hunting, all from the same chevron station. I filled my Javelina tag this morning so I won't be going hunting again until next friday. I nailed me a pig with my ol 54 cal muzzleloader. It won't get driven much this week except for on monday and tuesday to go target shooting and then on friday when the next javelina hunt starts. It's really starting to look like my jeep likes drinking circle K gas about as much as I like drinking soured milk. Now that the tank is almost full I think I'm gonna dump about a half a bottle of rubbing alcohol in there just for luck. Ok, so the chevron gas cost an extra $2.40 per fill-up. Oh well. If it keeps the jeep from PMSing then it's well worth it.
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 33
Likes: 0
From: Tucson, AZ
Year: 1987
Model: Cherokee
Engine: 4.0
Yeah they're pretty good eating if they're done right. And ya gotta be careful not to cut into the scent gland when you're skinning it or the meat is ruined. It's very lean and kinda smells like deer meat. I use the back straps for crock pot stews (potatoes, celery, beef stew flavoring packet, and assorted other seasonings) and I grind up the rest with a lot of cheap super fatty bacon and make hamburgers. I ended up with 18 1/2 lbs of meat out of this last one. I may do some sausage out of this one too.
I did sloppy-joes out of a jackrabbit but it took a LOT of seasoning and Jack Daniels BBQ sauce to get the "gamey" out of that. They do much better in stews. Jacks need to soak in water with sea salt in the fridge for 24 hours or until all the blood is out and then cooked real slow. The sloppy-jacks would have been better if I had soaked it first but I was in a hurry and ground it up fresh with just a little bacon in it. The jacks are usually only good to eat in months that end in "R" (sept thru dec).
I did sloppy-joes out of a jackrabbit but it took a LOT of seasoning and Jack Daniels BBQ sauce to get the "gamey" out of that. They do much better in stews. Jacks need to soak in water with sea salt in the fridge for 24 hours or until all the blood is out and then cooked real slow. The sloppy-jacks would have been better if I had soaked it first but I was in a hurry and ground it up fresh with just a little bacon in it. The jacks are usually only good to eat in months that end in "R" (sept thru dec).
Last edited by holeshot9g; Feb 16, 2013 at 01:56 PM.
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Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Yeah they're pretty good eating if they're done right. And ya gotta be careful not to cut into the scent gland when you're skinning it or the meat is ruined. It's very lean and kinda smells like deer meat. I use the back straps for crock pot stews (potatoes, celery, beef stew flavoring packet, and assorted other seasonings) and I grind up the rest with a lot of cheap super fatty bacon and make hamburgers. I ended up with 18 1/2 lbs of meat out of this last one. I may do some sausage out of this one too.
I did sloppy-joes out of a jackrabbit but it took a LOT of seasoning and Jack Daniels BBQ sauce to get the "gamey" out of that. They do much better in stews. Jacks need to soak in water with sea salt in the fridge for 24 hours or until all the blood is out and then cooked real slow. The sloppy-jacks would have been better if I had soaked it first but I was in a hurry and ground it up fresh with just a little bacon in it. The jacks are usually only good to eat in months that end in "R" (sept thru dec).
I did sloppy-joes out of a jackrabbit but it took a LOT of seasoning and Jack Daniels BBQ sauce to get the "gamey" out of that. They do much better in stews. Jacks need to soak in water with sea salt in the fridge for 24 hours or until all the blood is out and then cooked real slow. The sloppy-jacks would have been better if I had soaked it first but I was in a hurry and ground it up fresh with just a little bacon in it. The jacks are usually only good to eat in months that end in "R" (sept thru dec).
Sounds yummy.