Post by Cowboy Camper on Jan 11, 2010 20:34:15 GMT -6
T.B.I. (TBI from here on out) is the acronym for the Throttle Body Injection system on the older trucks, mostly on trucks at or older then 1995 or so. GM, Ford and Chrysler all had the TBI systems a few years before 'graduating' up to the modern EFI or SEFI (Electronic Fuel Injection & Sequential Electronic Fuel Injection, respectively) as we know them these days. * Foot note below
The TBI system is called fuel injection, but it's really more like a glorified Carburetor compared to the EFI/SEFI systems of today. The TBI system has an air delivery Throttle Body that contains 2 injectors on a V-6 or V-8 engine, as well as the throttle plates themselves that control the intake air flow. This unit sits on top of the intake manifold and from the outside it pretty much looks like an old carburetor and it even has the typical old style round air filter assembly sitting on top.
* About the EFI/SEFI systems: The key difference here (compared to the TBI system) is the fact that there are injectors placed at each individual cylinder's intake port deeper inside the intake manifold. Thus a V-6 has 6 injectors and an 8 cylinder has... well, 8. Also, the key difference between EFI and SEFI is the way in which the injectors are fired. EFI fires all of the injectors at once (not unlike the TBI system) while the SEFI fires 2 injectors at a time in correlation to the Spark Plug firings in the ignition system. In other words, only 2 injectors are fired instead of all 6 or 8 at the same time. There is a unit called the throttle body in these systems also, but Only air intake is managed in this system at the throttle body, and often times the air intake duct works and air filter assemblies look little like the old style round air filters on top of the engine/intake manifold.
OK, Back to the injector replacement on the TBI system... the focus of this post. In this system that only has 2 injectors for the entire engine, one can imagine the Power Loss associated with the lack of 1 injector. In the example I'm writing about, the loss of one injector took the truck down to 30 MPH Max. Not good, huh? Of course not!
My dad's neighbor has this Dodge truck and I just had to fix this thing tonight. He went to the store yesterday to order the part in, but I found it online at the site today for a Pic of the injector. Here's a Link to the page I found that shows the part and that it was almost $100 bucks. Autozone's Part Display Page
Being the middle of Winter and running a little late for another appointment this evening, I didn't get any personal Pics tonight. But I really want to get some together in my Webshots Gallery, cause this is REALLY a simple Repair that I'd like to illustrate for y'all. The complete repair involved a T-20 Torx screwdriver, a regular Pliers, and a spray can of Lube to slick up the new 'O' Rings on the injector to slip it back into it's bore in the throttle body unit. This job took all of about 10 to 15 minutes, the neighbor got the truck back up to 60 MPH on a test run, and I was hardly late for that appointment after all. ;D
I do not know when I'll be able to get the Pic Series done, but hopefully fairly soon. Typical of me, I didn't consider this idea of a teaching moment until after the job was done. Sort of like my Trans Fluid Flush post, the idea to pass on my experiences didn't come to mind until after the fact. (Well, when there's a Job to do, who's thinking about Documenting it at the time?)
Like the Trans Fluid Flush job, I fully expect to tell the whole story in the captions under the Pics at the Gallery. So look for it soon, and know full well that I will let y'all know when the Pics are up.
Thanks!
The TBI system is called fuel injection, but it's really more like a glorified Carburetor compared to the EFI/SEFI systems of today. The TBI system has an air delivery Throttle Body that contains 2 injectors on a V-6 or V-8 engine, as well as the throttle plates themselves that control the intake air flow. This unit sits on top of the intake manifold and from the outside it pretty much looks like an old carburetor and it even has the typical old style round air filter assembly sitting on top.
* About the EFI/SEFI systems: The key difference here (compared to the TBI system) is the fact that there are injectors placed at each individual cylinder's intake port deeper inside the intake manifold. Thus a V-6 has 6 injectors and an 8 cylinder has... well, 8. Also, the key difference between EFI and SEFI is the way in which the injectors are fired. EFI fires all of the injectors at once (not unlike the TBI system) while the SEFI fires 2 injectors at a time in correlation to the Spark Plug firings in the ignition system. In other words, only 2 injectors are fired instead of all 6 or 8 at the same time. There is a unit called the throttle body in these systems also, but Only air intake is managed in this system at the throttle body, and often times the air intake duct works and air filter assemblies look little like the old style round air filters on top of the engine/intake manifold.
OK, Back to the injector replacement on the TBI system... the focus of this post. In this system that only has 2 injectors for the entire engine, one can imagine the Power Loss associated with the lack of 1 injector. In the example I'm writing about, the loss of one injector took the truck down to 30 MPH Max. Not good, huh? Of course not!
My dad's neighbor has this Dodge truck and I just had to fix this thing tonight. He went to the store yesterday to order the part in, but I found it online at the site today for a Pic of the injector. Here's a Link to the page I found that shows the part and that it was almost $100 bucks. Autozone's Part Display Page
Being the middle of Winter and running a little late for another appointment this evening, I didn't get any personal Pics tonight. But I really want to get some together in my Webshots Gallery, cause this is REALLY a simple Repair that I'd like to illustrate for y'all. The complete repair involved a T-20 Torx screwdriver, a regular Pliers, and a spray can of Lube to slick up the new 'O' Rings on the injector to slip it back into it's bore in the throttle body unit. This job took all of about 10 to 15 minutes, the neighbor got the truck back up to 60 MPH on a test run, and I was hardly late for that appointment after all. ;D
I do not know when I'll be able to get the Pic Series done, but hopefully fairly soon. Typical of me, I didn't consider this idea of a teaching moment until after the job was done. Sort of like my Trans Fluid Flush post, the idea to pass on my experiences didn't come to mind until after the fact. (Well, when there's a Job to do, who's thinking about Documenting it at the time?)
Like the Trans Fluid Flush job, I fully expect to tell the whole story in the captions under the Pics at the Gallery. So look for it soon, and know full well that I will let y'all know when the Pics are up.
Thanks!