10% MPG Improvement + Better Drivability
Senior Member
Joined: Jun 2010
Posts: 632
Likes: 1
From: Ft. Myers, Fl.
Year: 1997, 1999
Model: Cherokee
Engine: 4.0
I finally got around to putting my wideband in my jeep this week. I took it for a spin and under load I was at 14.5:1 and flooring it I was around 13.8:1 around 3k rpm and by recline it was around 12.5:1. It almost seems like these injectors might be a little small.
Discuss.....
Discuss.....
Senior Member
Joined: Aug 2011
Posts: 760
Likes: 6
From: Landers, CA
Year: Several
Model: Cherokee
Engine: 4.0
Wouldn't it be nice if people read how it works rather than pretending?
""""""The Map only comes into play at Wide Open Throttle, (70-80%), and any other open loop condition""""
The MAP is used ALL THE TIME except at except at WOT.
It looks at the reading before you start it - that's atmospheric - then compares Manifold Air Pressure (vacuum) to it to determine how much air is entering. Then the PCM uses that info to vary the injector time to get the appropriate amount of fuel.
The O2's feed back info about how well it's doing it's job.
The TPS throttle position - like an accelerator pump on a carb. And it tells the PCM if it's at WOT - and it varies timing a little.
At WOT the MAP is ignored, the PCM just gives as much open time to the injectors as it can. That's the ONLY time bigger injectors - higher flow - actually do anything.
Those that experience anything else are experiencing the placebo effect.
Since the RENIX is pre-programed for injection time - and 'forgets" every time it shuts off, it takes a moment for it to realize it's dumping too much fuel - info is from the O2 sensor.
The FSM's explain all that.
""""""The Map only comes into play at Wide Open Throttle, (70-80%), and any other open loop condition""""
The MAP is used ALL THE TIME except at except at WOT.
It looks at the reading before you start it - that's atmospheric - then compares Manifold Air Pressure (vacuum) to it to determine how much air is entering. Then the PCM uses that info to vary the injector time to get the appropriate amount of fuel.
The O2's feed back info about how well it's doing it's job.
The TPS throttle position - like an accelerator pump on a carb. And it tells the PCM if it's at WOT - and it varies timing a little.
At WOT the MAP is ignored, the PCM just gives as much open time to the injectors as it can. That's the ONLY time bigger injectors - higher flow - actually do anything.
Those that experience anything else are experiencing the placebo effect.
Since the RENIX is pre-programed for injection time - and 'forgets" every time it shuts off, it takes a moment for it to realize it's dumping too much fuel - info is from the O2 sensor.
The FSM's explain all that.
CF Veteran
Joined: Nov 2011
Posts: 2,322
Likes: 1
From: Edmonton
Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by rrich
Wouldn't it be nice if people read how it works rather than pretending?
""""""The Map only comes into play at Wide Open Throttle, (70-80%), and any other open loop condition""""
The MAP is used ALL THE TIME except at except at WOT.
It looks at the reading before you start it - that's atmospheric - then compares Manifold Air Pressure (vacuum) to it to determine how much air is entering. Then the PCM uses that info to vary the injector time to get the appropriate amount of fuel.
The O2's feed back info about how well it's doing it's job.
The TPS throttle position - like an accelerator pump on a carb. And it tells the PCM if it's at WOT - and it varies timing a little.
At WOT the MAP is ignored, the PCM just gives as much open time to the injectors as it can. That's the ONLY time bigger injectors - higher flow - actually do anything.
Those that experience anything else are experiencing the placebo effect.
Since the RENIX is pre-programed for injection time - and 'forgets" every time it shuts off, it takes a moment for it to realize it's dumping too much fuel - info is from the O2 sensor.
The FSM's explain all that.
""""""The Map only comes into play at Wide Open Throttle, (70-80%), and any other open loop condition""""
The MAP is used ALL THE TIME except at except at WOT.
It looks at the reading before you start it - that's atmospheric - then compares Manifold Air Pressure (vacuum) to it to determine how much air is entering. Then the PCM uses that info to vary the injector time to get the appropriate amount of fuel.
The O2's feed back info about how well it's doing it's job.
The TPS throttle position - like an accelerator pump on a carb. And it tells the PCM if it's at WOT - and it varies timing a little.
At WOT the MAP is ignored, the PCM just gives as much open time to the injectors as it can. That's the ONLY time bigger injectors - higher flow - actually do anything.
Those that experience anything else are experiencing the placebo effect.
Since the RENIX is pre-programed for injection time - and 'forgets" every time it shuts off, it takes a moment for it to realize it's dumping too much fuel - info is from the O2 sensor.
The FSM's explain all that.
CF Veteran
Joined: Nov 2011
Posts: 2,322
Likes: 1
From: Edmonton
Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by notop46
Hi,
All modern injectors use the same o-ring sizes. The o-rings on the engine side are a little tougher to withstand heat of the manifold. The rail o-rings are softer to seal the fuel better. Older injector o-rings may no hold up against E10 E15 or E85 as newer ones. Just make sure you get the right o-rings on the right end of the injector.
All modern injectors use the same o-ring sizes. The o-rings on the engine side are a little tougher to withstand heat of the manifold. The rail o-rings are softer to seal the fuel better. Older injector o-rings may no hold up against E10 E15 or E85 as newer ones. Just make sure you get the right o-rings on the right end of the injector.
CF Veteran
Joined: Jan 2009
Posts: 1,964
Likes: 6
From: Baltimore, Maryland
Year: 1994 1993
Model: Cherokee
Engine: 4.0
This is all correct. Anytime I sell injectors to someone and they are concerned about one flowing at + or - 10% of factory injectors I tell them not to worry since all that gets adjusted anyway by so many things on modern vehicles. The main purpose of the "upgrade" isn't really the amount of fuel it's for the 4-port spray pattern the upgrade injectors use over the stock single port.
Wouldn't it be nice if people read how it works rather than pretending?
""""""The Map only comes into play at Wide Open Throttle, (70-80%), and any other open loop condition""""
The MAP is used ALL THE TIME except at except at WOT.
It looks at the reading before you start it - that's atmospheric - then compares Manifold Air Pressure (vacuum) to it to determine how much air is entering. Then the PCM uses that info to vary the injector time to get the appropriate amount of fuel.
The O2's feed back info about how well it's doing it's job.
The TPS throttle position - like an accelerator pump on a carb. And it tells the PCM if it's at WOT - and it varies timing a little.
At WOT the MAP is ignored, the PCM just gives as much open time to the injectors as it can. That's the ONLY time bigger injectors - higher flow - actually do anything.
Those that experience anything else are experiencing the placebo effect.
Since the RENIX is pre-programed for injection time - and 'forgets" every time it shuts off, it takes a moment for it to realize it's dumping too much fuel - info is from the O2 sensor.
The FSM's explain all that.
""""""The Map only comes into play at Wide Open Throttle, (70-80%), and any other open loop condition""""
The MAP is used ALL THE TIME except at except at WOT.
It looks at the reading before you start it - that's atmospheric - then compares Manifold Air Pressure (vacuum) to it to determine how much air is entering. Then the PCM uses that info to vary the injector time to get the appropriate amount of fuel.
The O2's feed back info about how well it's doing it's job.
The TPS throttle position - like an accelerator pump on a carb. And it tells the PCM if it's at WOT - and it varies timing a little.
At WOT the MAP is ignored, the PCM just gives as much open time to the injectors as it can. That's the ONLY time bigger injectors - higher flow - actually do anything.
Those that experience anything else are experiencing the placebo effect.
Since the RENIX is pre-programed for injection time - and 'forgets" every time it shuts off, it takes a moment for it to realize it's dumping too much fuel - info is from the O2 sensor.
The FSM's explain all that.
Thread Starter
Seasoned Member
Joined: Jun 2010
Posts: 448
Likes: 0
From: Charleston, SC
Year: 1990 - 2000
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Nov 2011
Posts: 2,322
Likes: 1
From: Edmonton
Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by notop46
I am showing 2 differentsizes for the ev14 injectors. The upper is 7.52 x 3.51 made from Viton GLK, and the lower is 8.30 x 3.05 made from Viton B.
Buna-N is used extensively in the oil and gas industry for process fluids.
Where do you get your info?
Viton details:
http://www.pspglobal.com/nfvitongrades.html
Buna details:
http://www.sisweb.com/vacuum/o-rings/buna.htm
CF Veteran
Joined: Jan 2009
Posts: 1,964
Likes: 6
From: Baltimore, Maryland
Year: 1994 1993
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Nov 2011
Posts: 2,322
Likes: 1
From: Edmonton
Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by Programbo
I use the Viton-F (Fluoroelastomer) on all the injectors I sell.
Dunno, in the end if it works, great. They're not expensive to replace...
CF Veteran
Joined: Jan 2009
Posts: 1,964
Likes: 6
From: Baltimore, Maryland
Year: 1994 1993
Model: Cherokee
Engine: 4.0
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 did an experiment. I needed to know for sure so...Viton Buna-N O-R in gas, alcohol, mineral spirits or acetone, after a month would not leave a streak on white paper. For what that's worth!
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
They seemed unfazed. Both the gas and the alcohol discolored a little. Was usually pretty warm, sun might have discolored the gas. Idk about alcohol..
Wiping on the white paper and just feeling that they, (the segments) seemed the same was all I did. If you need an O ring for your pump sprayer, PM me! I can guarantee they wont dissolve in 30 days!
Wiping on the white paper and just feeling that they, (the segments) seemed the same was all I did. If you need an O ring for your pump sprayer, PM me! I can guarantee they wont dissolve in 30 days!
Last edited by DFlintstone; May 18, 2012 at 09:24 PM.
CF Veteran
Joined: Nov 2011
Posts: 2,322
Likes: 1
From: Edmonton
Year: 1990
Model: Cherokee
Engine: 4.0
Hmmm, the bubbled orings I've seen, spent all their service life under pressure. Then, when pressure is absent, read: plant shutdown, the absence of pressure let's all the fuel or whatever has been forced into the seal to expand and literally push itself out. It literally looked like it was boiling! Some valves would still hold pressure until we started busting them open...then you could hear the orings snapping and popping as the gases were being released. Weird stuff.