80 Pounders

[scooterwrench]

Hey Folks.
I'm gathering up the pieces for the 355 swap into ol Smoky. One of the pieces is a 454 TB that I want to install on top of my current Edelbrock spreadbore manifold. The engine has a Lunati cam(262-268,112CL and .499-.521 lift with 1.6 rockers)and a lot of headwork. I've read that the 80lb injectors are a little large for a 350 engine and affects idle quality and seems you can't turn the pulse width down enough to compensate for it. From what I've read is to use 65-68lb injectors and bump the fuel pressure up then do the math to determine BPW.

Your thoughts?

[Fast355]

Hey Folks.
I'm gathering up the pieces for the 355 swap into ol Smoky. One of the pieces is a 454 TB that I want to install on top of my current Edelbrock spreadbore manifold. The engine has a Lunati cam(262-268,112CL and .499-.521 lift with 1.6 rockers)and a lot of headwork. I've read that the 80lb injectors are a little large for a 350 engine and affects idle quality and seems you can't turn the pulse width down enough to compensate for it. From what I've read is to use 65-68lb injectors and bump the fuel pressure up then do the math to determine BPW.

Your thoughts?

I had a 2" bore 502 Marine TBI and 104 lb/hr each injector on my 350. Zero issues getting it to idle and the fueling correct. Ran that setup on a single plane manifold as well.

[scooterwrench]

[QUOTE=Fast355;99682]I had a 2" bore 502 Marine TBI and 104 lb/hr each injector on my 350. Zero issues getting it to idle and the fueling correct. Ran that setup on a single plane manifold as well.[/QUOTE


My motor is almost 50" smaller and running a dual plane manifold. Think I can still run the 80lb injectors with stock pressure?

[scooterwrench]

Oops! I missed that you were running a 350 under that 502 manifold.
Dismiss that part if my previous post.

[scooterwrench]

Ok folks, it's all under the hood now and will be finishing the exhaust tomorrow morning. I did fire it with open headers and it ran decent for a few seconds then started falling off. Any ideas as to where I should start as far as pulse width and where in the mask should I make the changes? Scalars? Tables? Both? I'm starting off with 14lbs fuel pressure and will increase as needed to try to keep my duty cycle at or below 90% at WOT and 5800 revs.

7427, $0D mask.

[1project2many]

$0D uses the actual injector flow in the calibration. It's located at 0x4D88 and 0x4D89. What are you using for tuning package? What definition file?


Folks sometimes switch the FPR cover out for a vacuum referenced cover to reduce pressure at idle.

[scooterwrench]

[QUOTE=1project2many;104449 What are you using for tuning package? What definition file?


Folks sometimes switch the FPR cover out for a vacuum referenced cover to reduce pressure at idle.[/QUOTE]

TunerPro RT, $0D definition.

FPR cover? Are you talking about the spring cup? That is next on the list of things to do. I already know that 14psi is not going to be enough pressure for heavy demand. Right now I'm trying to get back on the road.

[scooterwrench]

$0D uses the actual injector flow in the calibration. It's located at 0x4D88 and 0x4D89.

I've set that to 80lbs.

[dave w]

Often the injector flow rate is tweaked in the PROM Chip. Injector flow rate setting in the PROM Chip is often a "course tune" setting. Data log BLM averages are a good way to determine if the injector flow rate is correct for the engine. If all BLM averages are rich, adjust the injector flow rate accordingly. If all BLM averages are lean, adjust the injector flow rate accordingly. If some of the BLM averages are lean and some the BLM average are rich, the next step is to adjust the VE (fuel) table or tables.

Example of ALL but two BLM averages Lean.

BLM - Near Idle.jpg

BLM - Off Idle.jpg

[scooterwrench]

Often the injector flow rate is tweaked in the PROM Chip. Injector flow rate setting in the PROM Chip is often a "course tune" setting. Data log BLM averages are a good way to determine if the injector flow rate is correct for the engine. If all BLM averages are rich, adjust the injector flow rate accordingly. If all BLM averages are lean, adjust the injector flow rate accordingly. If some of the BLM averages are lean and some the BLM average are rich, the next step is to adjust the VE (fuel) table or tables.

Example of ALL but two BLM averages Lean.

BLM - Near Idle.jpg

BLM - Off Idle.jpg

Thanks dave, I was just looking for a starting point. Figure I'll be datalogging and tuning once I get it up and running well enough to hit the road.
Is there a way to change the parameter for code 33, MAP high in $0D? When I fired it the other day it immediately set code 33 and my MAP was at 67.3 at idle. Pretty sure that's caused by the cam and 1.6 rockers. For now I've just unchecked the flag for it.

[1project2many]

I'm sorry, I probably should have been more specific in my question. There are many $0D definition files around for Tunerpro. This one is well designed and has parameters for an electric fan if you decide to go that route. https://www.gearhead-efi.com/Fuel-In...2&d=1378742745. There are others so you should use one that you are comfortable with.

A vacuum referenced fuel pressure regulator will lower pressure during idle and other times when manifold vacuum is high. There are multiple ways to set this up. One bolt-in solution is here: https://www.ebay.com/itm/167003895353?gQT=1

Yes, you can change the parameters to set code 33. You can also disble the code entirely. If your definition file doesn't have the parameters you need they can be added.

[scooterwrench]

I'm sorry, I probably should have been more specific in my question. There are many $0D definition files around for Tunerpro. This one is well designed and has parameters for an electric fan if you decide to go that route. https://www.gearhead-efi.com/Fuel-In...2&d=1378742745. There are others so you should use one that you are comfortable with.

A vacuum referenced fuel pressure regulator will lower pressure during idle and other times when manifold vacuum is high. There are multiple ways to set this up. One bolt-in solution is here: https://www.ebay.com/itm/167003895353?gQT=1

Yes, you can change the parameters to set code 33. You can also disble the code entirely. If your definition file doesn't have the parameters you need they can be added.

Thanks! Yeah, I've seen those VRFPR's and have thought of building my own version of it with a threaded cap on the bottom of the spring cup to make spring changes easier. Also I wouldn't be able to use the air breather riser so the vacuum port would have to be in the bottom. I'm running an '87 TB with the factory spreadbore adapter and it's 1-1/2" tall and sitting on top of of an Edelbrock air gap spreadbore manifold. My breather to hood clearance is only about 1" now.

The MAP parameter or setting I was talking about is the high MAP limit with the throttle is closed at where it sets code 33. I'm not sure where it is set now but if I could change it to say 80 to set the code I could still run the flag and not get the light.

[scooterwrench]

Anybody got a .bin for 7427 ,$0D and 7.4L? The one in the 7427 thread doesn't work with $0D

[scooterwrench]

OK, new issue. This one concerns the IAC. I had done the 7747-7427 swap while the 305 was still in it and the IAC worked fine. The 305 TB uses the square four terminal weatherpack connector and the 454 TB uses the inline four terminal micropack connector. I wired it like it is displayed in the FSM but it doesn't seem to be working right.
The wires are as such,
Terminals
A= lt blu/blk
B= lt blu/wht
C= lt grn/wht
D= lt grn/blk

Seems it's working backwards and opening the IAC when it's supposed to be closing it. I did the A&B jumper on the ALDL to seat the IAC to set the curb idle and it pulled the IAC open and when I put it in gear the engine slows. The IAC I bought was supposed to be for an '87(year of TB)454 but these days you don't always get what want.
My question were there differences in the internal wiring of the IAC's over different years and models?

[stew86MCSS396]

Post #6