454 TBI, yes/no good/bad idea?

[bkahler]

Originally Posted by dadstoy

I'm keeping my Quadra-Jet. It works very well. Just saying!

Well where's the fun in that?

Speaking for myself, my whole 454 & TH400 (not 475) transmission combo has mostly been pieced together from scratch. My coach came to me with the orgininal 454 and TH475 missing. It came with a 350 and TH400 where the install was never finished.

I definitely want to install the 4L80e transmission but after reading about Mel's issues with his aftermarket controller for his 4L80e that reinforced my opposition to aftermarket electronics. If the Argosy was something to tinker with then aftermarket goodies would be fine but not for something I plan to use for long trips and I want dependability more than I want the latest and greatest.

Since I need to use the Chevy ECM to control the transmission the next logical step (to me anyway!) is to add the Chevy TBI. Especially considering the engine is still sitting on the test stand waiting to be installed in the chassis. Sitting on the test stand means I can install the TBI and run the engine to work out most of the bugs prior to installing in the chassis.

Seems like a logical progression to me

[choctawmel]

Originally Posted by bkahler

I don't have any desire to use a system that doesn't use stock off the shelf hardware. I'm sure there's a thousand and one systems that are better than a stock oem tbi. I did some googling and found just as many people bad mouthing a stock tbi kit as there were people praising the same system. I think its all about managing your expectations. I would hope that a $2500+ sytems would be better than a $1000 system. But I'm comfortable with the thought that I can make a $1000 system work for my needs.

My 454 currently resides on a test stand. I should be able to install and test whatever system I buy and would hope that most bugs can be worked out on the test stand. One possible problem to over come is I have headers so I will need to figure out where to install the o2 sensor. I'll probably need a temporary collector and muffler for mounting the o2 sensor, but I think I can manage that.

Matt, where are you mounting the o2 sensor? If I remember right you still have the stock cast iron manifolds where I'll installing hedman headers.

The system I'm looking at comes with a fuel pump so as yet I've not done much research in that area. Off the top of my head I'm thinking a Holley Blue pump might work.

Brad

Brad, When I did my EFI 15 years again I started out with the o2 at as close of the head as possible, then I changes to a heated o2 and moved it to the header collector. Seemed to work better at the collector and it can read both barrels of the EFI.
As far as the fuel pump: Inline pumps are sucking and can develop pulses and air bubbles effecting the injector pressure. I went throw 3-4 injector pumps because they do not like to suck. That's the reason I put the in-tank pump in that is giving me nightmares with the diesel convection. I used the Fast in-tank pump kit from Summit for that.
I used the TCI transmission controller. But then I did the 4L80e 10 years after the EFI was put on.
After the 454 blow in Las Cruses last year and the fact I couldn't get the right PROM, I installed (I don't remember the name of it) a fully programmable computer just before the engine started to fail AGAIN. With the old CPM was running air/fuel of 19/1. Not good to do that for 2000 miles.
I talked to a person at 'affordable fuel injector' who sounded happy to help me with a new PROM just after I got the motor home back in Las Cruses. Then when I got home, they would only sell me the whole think. That's why I spent another $1300 on the new programmable CPU.

mel

[bkahler]

Originally Posted by choctawmel

Brad, When I did my EFI 15 years again I started out with the o2 at as close of the head as possible, then I changes to a heated o2 and moved it to the header collector. Seemed to work better at the collector and it can read both barrels of the EFI.

Your experience with the o2 sensor matches with what I've been reading elsewhere. That works in my favor as I have ceramic coated Hedman headers. Having a heated o2 sensor in the collector would be my preference.

As far as the fuel pump: Inline pumps are sucking and can develop pulses and air bubbles effecting the injector pressure. I went throw 3-4 injector pumps because they do not like to suck. That's the reason I put the in-tank pump in that is giving me nightmares with the diesel convection. I used the Fast in-tank pump kit from Summit for that.

Do you remember if your inline electric pump installation was below tank level or somewhere above the bottom of the tank? I've been reading about inline pump issues and one point seems to be the inline pump has to be at or near the level of the bottom of the tank. Another comment was to use the stock mechanical pump to act as a "scavenger" pump for the inline pump. Supposedly with this arrangement the inline pump can be mounted anywhere down stream of the mechanical pump. I'm still trying to find out more
information about that arrangement.

The sending unit I bought for my fuel tank is from an in-tank fuel system so if I can modify the sending unit to fit my tank that might be the solution.

I used the TCI transmission controller. But then I did the 4L80e 10 years after the EFI was put on.

I was wondering which order you had done your installation.

After the 454 blow in Las Cruses last year and the fact I couldn't get the right PROM, I installed (I don't remember the name of it) a fully programmable computer just before the engine started to fail AGAIN. With the old CPM was running air/fuel of 19/1. Not good to do that for 2000 miles.
I talked to a person at 'affordable fuel injector' who sounded happy to help me with a new PROM just after I got the motor home back in Las Cruses. Then when I got home, they would only sell me the whole think. That's why I spent another $1300 on the new programmable CPU.

mel

So whose TBI system did you install the $1300 CPU in?

[PeterH-350LE]

Originally Posted by bkahler

..


Do you remember if your inline electric pump installation was below tank level or somewhere above the bottom of the tank? I've been reading about inline pump issues and one point seems to be the inline pump has to be at or near the level of the bottom of the tank. Another comment was to use the stock mechanical pump to act as a "scavenger" pump for the inline pump. Supposedly with this arrangement the inline pump can be mounted anywhere down stream of the mechanical pump. I'm still trying to find out more
information about that arrangement.

Brad, for what its worth, Holley recommends to remove the mechanical fuel pump altogether and mount the electr fuel pump as close to the tank as possible and not higher than the lowest point of the tank.
My Holley commander 950 system has the mechanical fuel pump removed and has a second low pressure fuel pump by the tank with the high pressure EFI pump mounted at the rear of the engine.
The obvious benefit of removing the mechanical fuel pump is the elimination of the fuel lines running to the front of the engine in an already crowded and hot space. Also placing the EFI pump between the mechanical fuel pump and the throttle body would not place it as close to the fuel tank as possible.
My system is set up with a "surge" tank for the fuel issue. The surge tank gets filled by the low pressure pump in the rear and eliminates the questionable below tank mounting of the EFI pump. The surge tank has a return line to the main tank and also is the receiver for the throttle body return line.

[Keyair]

One of my concerns as I plan my conversion is the return lines.
I have not found out what size they need to be.

I found this site and this site and this page that deals with Drac/VSS calibration.
VSSB DRAC Calibration | Harris Performance, INC

For reference, here are the 3 TBI Ecu units I own.

From my 87 Suburban 2wd 3/4t 454.
This is a 1227747 AFTH


From a 1990 Suburban 3/4t 2wd 454.
This is a 1227747 ANTY



And the TBI/4L80e controller...
This unit is labeled:16197427 BJYL
16197427 and was used in 1994 - 1995 C/K Truck, Van, S-10, 4.3L, 5.7L & 7.4L


Note also that they are one single plug, as they only control the TBI, where as the last one has twin plugs, one for the TBI, and the other from the trans controller.
From what I was able to glean, the '87 and '90 Ecms are the same, and the letters after denote the "Tune" they are flashed with.
The 95 ECM is the fastest and most tunable ECM, and it seems that you can use THAT ecm, with wiring repins to control the TBI on the earlier vehicles, AND the 4L80e..

[Keyair]

One of my concerns as I plan my conversion is the return lines.
I have not found out what size they need to be.

I found this site and this site and this page that deals with Drac/VSS calibration.
VSSB DRAC Calibration | Harris Performance, INC

For reference, here are the 3 TBI Ecu units I own.

From my 87 Suburban 2wd 3/4t 454.
This is a 1227747 AFTH


From a 1990 Suburban 3/4t 2wd 454.
This is a 1227747 ANTY


And the TBI/4L80e controller...
This unit is labeled:16197427 BJYL
16197427 and was used in 1994 - 1995 C/K Truck, Van, S-10, 4.3L, 5.7L & 7.4L


Note also that they are one single plug, as they only control the TBI, where as the last one has twin plugs, one for the TBI, and the other from the trans controller.
From what I was able to glean, the '87 and '90 Ecms are the same, and the letters after denote the "Tune" they are flashed with.
The 95 ECM is the fastest and most tunable ECM, and it seems that you can use THAT ecm, with wiring repins to control the TBI on the earlier vehicles, AND the 4L80e..

[bkahler]

Originally Posted by PeterH-Airstreamer

Brad, for what its worth, Holley recommends to remove the mechanical fuel pump altogether and mount the electr fuel pump as close to the tank as possible and not higher than the lowest point of the tank.
My Holley commander 950 system has the mechanical fuel pump removed and has a second low pressure fuel pump by the tank with the high pressure EFI pump mounted at the rear of the engine.

Peter, everything I've read up to this point also mentioned removing the mechanical pump completely. I was reviewing the installation manual for the AFI TBI system and came across this paragraph:

"Recent fuel pump installations have kept the vehicle’s mechanical fuel pump intact and used it as scavenger pump for the electric fuel pump. With this type of installation the electric fuel pump can be mounted in any location that you would choose, as a constant fuel flow is available for the electric pump. Ensure that the fuel filter is still installed between the mechanical and the electric pump if you choose this type of fuel pump installation."

I was somewhat surprised when I read it and have been searching for more info on the subject but haven't come up with much.

The obvious benefit of removing the mechanical fuel pump is the elimination of the fuel lines running to the front of the engine in an already crowded and hot space. Also placing the EFI pump between the mechanical fuel pump and the throttle body would not place it as close to the fuel tank as possible.
My system is set up with a "surge" tank for the fuel issue. The surge tank gets filled by the low pressure pump in the rear and eliminates the questionable below tank mounting of the EFI pump. The surge tank has a return line to the main tank and also is the receiver for the throttle body return line.

I do like the idea of eliminating the mechanical pump and was caught off guard by the statement about using it as a scavenger pump. I plan on asking AFI about it.

Can you post a picture of your surge tank? I've not ran across references anywhere to the use of a surge tank with TBI.

Brad

[bkahler]

Originally Posted by Keyair

One of my concerns as I plan my conversion is the return lines.
I have not found out what size they need to be.

I don't plan on changing return line size which was 1/4" on my 74 chassis. The fuel tank sending unit that I bought that is designed as an intank fuel pump unit has a 1/4" return line.

I found this site and this site and this page that deals with Drac/VSS calibration.
VSSB DRAC Calibration | Harris Performance, INC

I ran across the tbichips site a while back. It helped me determine which VSSB I needed. However I can't re-program it until I select my tires, I already know my diff is a 4:10.

My ECM is 16168625.

[bkahler]

Steve, I just checked the feed and return pipe sizing on my Argosy and the feed is 3/8" and the return is 1/4". However I also just looked at the sending unit I will be using with my new fuel tank and it has a return pipe that is 5/16". This particular sending unit is from a late model Chevy truck with in-tank fuel pump.

That tells me I really should upgrade the size of the return pipe to 5/16". Fortunately that will be relatively easy as I've already removed all of the fuel lines from the chassis. I won't be doing running any new fuel lines until after I know for sure whether I'm going TBI or sticking with the carburetor.

Brad

[PeterH-350LE]

Originally Posted by bkahler

..

Can you post a picture of your surge tank? I've not ran across references anywhere to the use of a surge tank with TBI.

Brad

I will post a picture once i get time . Here is a write up about it:
Tech Page

[Keyair]

Dang... I was worried about the high speed cornering fuel starvation issue...

Seriously tho, looks like a solution.

Unless I lost my mind... Which is probable... My return pipes were all 5/16, EXCEPT the very first piece between the mechanical fuel pump and the chassis rail pipe. Brad had mentioned before about it being 1/4... And i will admit i had dismissed it as a difference between his setuo and mine... I had started at the rear and worked forward replacing rubber and some steel piping with 5/16... But when I did that last piece... 5/16 was a sloppy fit.. It was 1/4!

[PeterH-350LE]

Two points come to mind for using a surge tank
1. it reduces the length of pressurized section of the fuel line system
2. it relocates the EFI pump from a vulnerable location (lowest, closet point to main tank)
well, 3. Keyairs driving habits of hard cornering
Oh and 4. Brad buying tanks without baffles

[bkahler]

Originally Posted by PeterH-Airstreamer

Two points come to mind for using a surge tank
1. it reduces the length of pressurized section of the fuel line system
2. it relocates the EFI pump from a vulnerable location (lowest, closet point to main tank)

All good points and valid reasons for a surge tank.

well, 3. Keyairs driving habits of hard cornering

Well...you know those Brits, they aren't use to driving large vehicles

Oh and 4. Brad buying tanks without baffles

Not much I can do when it's the only one available on the market...

[bkahler]

Next time I talk to Affordable Fuel Injection I plan on asking them about surge tanks and their recommendations relating to them. A quick search on ebay turned up a broad range of surge tanks being available. Considering my fuel tank has zero baffles a surge tank makes sense possibly even for just a carburetor engine. Not sure what size would be appropriate, possibly Peter can answer that based on what's installed on his 310.

Finding a suitable location for a gallon sized tank could be an issue. Hopefully a 1/2 gallon or smaller would be sufficient.

Here's a couple of surge tank found on ebay:

1/2 gallon surge tank

1 gallon surge tank

[PeterH-350LE]

Originally Posted by bkahler

... Not sure what size would be appropriate, possibly Peter can answer that based on what's installed on his 310.

Finding a suitable location for a gallon sized tank could be an issue. Hopefully a 1/2 gallon or smaller would be sufficient.

Here's a couple of surge tank found on ebay:

1/2 gallon surge tank

1 gallon surge tank

The tank appears to be max 1 gal, maybe less. Its mounted against the passenger side wall above the transmission. Looking down into the engine compartment from inside, you just can barely see it.
Its hard to take a picture. This one is from above the passenger side exhaust manifold looking backwards. All you see is some metal and blue lettering. I have to go and pull the O2 sensor, maybe I can get a better shoot at it.
For some reason my AF mixture dropped down to 11.5 at idle. Its fine at higher RPM's, just can't figure out why it changed. Some say, its not that critical at idle, what counts is under load at higher RPM

[bkahler]

Thanks for the picture. I get the general idea of where it's located.

So what's the controller that I've circled in red?

[PeterH-350LE]

Originally Posted by bkahler

Thanks for the picture. I get the general idea of where it's located.

So what's the controller that I've circled in red?
Attachment 255177

thats the wideband O2 sensor
http://www.innovatemotorsports.com/

[bkahler]

Wow, I wasn't expecting it to be an o2 sensor! Just shows you how much I know about these new fangled devices

Is this a standalone gauge or is it used as part of your TBI system?

[PeterH-350LE]

Originally Posted by bkahler

Wow, I wasn't expecting it to be an o2 sensor! Just shows you how much I know about these new fangled devices

Is this a standalone gauge or is it used as part of your TBI system?

I am with you on the steep learning curve.
The wide band O2 sensor is part of the TBI system, since the ECU is calculating and correcting its fueling level based on the values from the O2 sensor. This is also referred to as a closed loop. In addition to that it has its own serial port connection to monitor and fine tune the sensor.
The simpler narrow band O2 sensor can accurately indicate an AF ratio of 14.7 that corresponds to an output voltage of appr .45 volts. Any voltage above or below that will cause the ECU to modify the pulse width of the injectors.
A wide band (in my case) can accurately indicate AF ratios from 10:1 to 20:1 The ECU can be programmed to maintain an AF ratio somewhere in that range, based on the type of engine and operating conditions.
And this is the point where I am deeply involved right now.
If you are interested this is what I can observe with the wide band O2 sensor:
11.5 -12 at idle which is too rich and I am trying to figure out why and what to do about it.
A perfect score of ~14.5 at 2800 RPM and upon deceleration leaning out to 18:1 back down to idle and 11.5-12 within seconds.
I think the wide band O2 sensor/system is the way to go, but it may take a little more work to fine tune
If anyone has more experience with the fine tuning of the O2 sensor input, I would greatly appreciate it. This is not system specific, its universal to TBI

[Keyair]

The thing you circled is the connector I think. I have the Innovate too. That's about where mine is but on the driver's side.