TPI worth it for SBC 40?

[Tools R Us]

Snagged a TBI setup off of a '90 van at the pick and pull and stuck it on a 350, FJ40. Took some work, but was stupid cheap and ran/worked great, way better than the carb.

 

[tdskip]

@Tools R Us - what was the hardest part?

 

[Tools R Us]

@Tools R Us - what was the hardest part?

Probably researching what to keep and reducing, configuring, the factory harness to work. First, removed everything not related to the TBI. Mounted the parts on the motor and ran wires to them.

When everything was wired, removed the unused wires. Most of the wires hanging down were removed, went into the spare bin.

 

[bikersmurf]

Given how little I’ve been driving my 40, it doesn’t make it any easier to make a decision. I’ve not calculated mpg with the edelbrock carb, but it doesn’t seem any worse than the worn Q-jet I swapped out. With all the tinkering I’ve done with timing over the years and other tweaking, I used to get about 12 mpg in town and 15-16 highway (best was about 17) all in US gallons.
Getting to the point, there’s not much to gain by going to efi... but with current gas prices nearing $5usd/gal, every bit does count.

By rejeting the 1406, I could narrow the gap, but for the same effort I could rebuild the Quadrajet and have a better off road carb. I know throttle response, and ease of starting would theoretically be better with efi, but it has never hesitated to start on the coldest of days... and with the top of I have to be light on the throttle to avoid wheel spin (even with 3.70s and 33s).

All that said, I’d still like to have it... and even 10% less fuel would add up. I’m waiting to hear back from the seller about going to see what is there. It’ll come down to price, I’ve decided I can live without it. However if he’s willing to let it go for the right price... it’ll make up my mind.

 

[terrx]

I guess it won't be a bad learning experience though I'm not sure you'll be satisfied until spending more time and money than you initially think.

One problem is the engine a TPI was designed for is a lot different than what you're putting it on. The ECM can account for some change, but not a lot. For example older slow burn heads need a lot more timing advance than heads on a TPI engine so the timing tables will be off by quite a bit especially at higher RPMs. You can replace the ECM with a pin-compatible upgraded ECM (dynamicefi.com P4 flash) which let's you tune it with a laptop.

@trona recently took a TPI setup off his 383 powered FJ40 after going to a newer 6.0. I think it'll be for sale soon if not already. Perhaps hit him up for info. I know he had the EBL P4 flash, zeitronix wide band O2 sensor, and other goodies.

 

[bikersmurf]

I guess it won't be a bad learning experience though I'm not sure you'll be satisfied until spending more time and money than you initially think.

One problem is the engine a TPI was designed for is a lot different than what you're putting it on. The ECM can account for some change, but not a lot. For example older slow burn heads need a lot more timing advance than heads on a TPI engine so the timing tables will be off by quite a bit especially at higher RPMs. You can replace the ECM with a pin-compatible upgraded ECM (dynamicefi.com P4 flash) which let's you tune it with a laptop.

@trona recently took a TPI setup off his 383 powered FJ40 after going to a newer 6.0. I think it'll be for sale soon if not already. Perhaps hit him up for info. I know he had the EBL P4 flash, zeitronix wide band O2 sensor, and other goodies.

Define Higher RPMs? Mine rarely see's 3k rpm.

 

[terrx]

I would guess above 2800-3000. You probably wouldn't notice a difference. The ECM should have a sticker on it with a code. A web search should bring up more info about what engine it was originally for, e.g. 305 or 350, and programming.

 

[SteveH]

TPI and TBI are two different things - is everyone in this thread referring to 'Throttle Body Injection' = TBI?

 

[jim land]

Tpi is from corvette, camaro, trans am and iroc z

 

[bikersmurf]

TPI
Tuned Port Injection

 

[SteveH]

But, everything in this thread is TBI, it appears.

 

[bikersmurf]

But, everything in this thread is TBI, it appears.

The first page started off as TPI.

So now I've gone and done it. I offered about $225 and he accepted it.

Based on the number on the box, it's a

1227165

87 - 88 Y & F CAR 5.0L / 5.7L TPI

also given that the center manifold bolt angles are slightly different.

Good news is that it is MAF which is more forgiving of a different cam. It has a VSS included (which may or may not match Cruiser RPMs). The runners are dent free and the wiring is in good shape.

So far, the bad news is that the distributor and leads are AWOL. This is part of why I low-balled... that and I was OK with walking away from a potential money hole.

 

[bikersmurf]

1987 Camaro with a 5.7

 

[jim land]

Good to see you teach yourself about tpi

 

[Dynosoar]

I run mine as a speed density setup. Indeed the MAF is more flexible, but I run a good size cam and it never had an issue. One less part to go bad with the speed density setup.
Dyno

 

[jim land]

This is my old thead for my tpi install , it is long and boring but it could help you or not

350 tpi help

forum.ih8mud.com

@lone gunman also have a good thread for tpi

 

[jim land]

this one can be hepful too

It is finally time to start my tuned port conversion

After several months of pinching pennies, I have finally orderd the last of the parts to install my TPI 350. Howell Engineering should come through with my harness and ecm sometime early this week! WOOHOO! I just finished assembly and paint of the long block. Here are some pics.

forum.ih8mud.com

 

[bikersmurf]

Money shots...

 

[bikersmurf]

Given I’ve never seen it installed, the more reference material the better.

First on the shopping list:
Distributor & Wires
45psi external fuel pump

 

[69LC]

Since you’re not a purist and willing to tinker, have fun. I gave up on my old junkyard SBC to go with a Mil spec diesel 6.2 and then sold it to buy the LQ4 sitting in the barn near my 40.