Would there be interest in a dodge TBI setup made for our cars?

[66plyValiant]

The OP wanted to know if there was interest in a tech guide, harness, or kit to use Mopar TBI on earlier carb equipped vehicles.

I'm interested.

What's happening here, and what seems to always happen on 318 build threads is called "scope creep". The original post is about a $300 cam upgrade that will work with stock valves, and the first 7 replies have the guy swapping in a 360 with a stoker kit and forged pistons, buying aluminum heads, and installing a converter and 4.56 gears to go with the custom grind roller cam that was recommended in reply number 2.

Why stop at MPI, why not go SMPI...why not direct?
Surely with just "a little more" work, you could simply move the injector bungs (which we don't have to F with on TBI) from the intake to the head.

While we're gathering our GM MPI units, why not just grab the 350, and install that at the same time?

thank you, I realize to everyone posting that Chebby TBI maybe better but for someone who is keeping the car near stock or a few upgrades dodge TBI isn't so bad, I have the parts at hand more so then Chev TBI stuff and could make a kit that almost anyone could afford, and would compare to buying a new 2 barrel in price, If I had access to chev stuff that cheapy I would try it

Yes and no. I agree that the topic has gone in some off directions at some points, but there has been some good info laid out about why 66plyValiant is going the way he is. Keeping in mind we are talking about TBI and not other, more advanced, forms of injection, I say it's a good option if the prices are reasonable. He has a good supply of parts and the knowledge to make a go of it. I say do it and wish him all the best.

I have a better understanding of the GM systems and am learning more on them as I have two complete JY sourced units that are going into some of my projects. (My old GMC parts chaser will probably get the first one). I ask questions and make statements based on what I have learned, if not just to help others but also to gain more knowledge. If I have offended anyone by my questions or comments, I apologize. I have learned some good things here.

What have you learned?

Thank you, I'm thinking I may go ahead and offer a few kits ranging from a how to guide to the harness all the way to a full kit to start with and see how it goes

earliest I would provide one is likely early spring still doing some planing and the next poll and thread would be where people want computer located, I used the rad support but I admagine some people may like it in another spot,

 

[needsaresto]

For me running tbi on an everyday basis in my G.M winter beater/pickup,I must admit the thing is rock solid reliable. It never fails to start. For a motor with 220 000+ k.m's it tired though. No ball's,not great fuel mileage,burn's lot's of oil. This 350 is done! But the tbi inj work's flawlessly.

 

[toddlaine]

I have a Howell TBI on My 86 CJ7. Works great installed it and have not had a single problem in years. Can have my jeep sit for months and starts right up. Thinking about TBI on my new Dart.

 

[Revhendo]

Thank you, I'm thinking I may go ahead and offer a few kits ranging from a how to guide to the harness all the way to a full kit to start with and see how it goes

earliest I would provide one is likely early spring still doing some planing and the next poll and thread would be where people want computer located, I used the rad support but I admagine some people may like it in another spot,

I'm interested in the how to guide for sure. I am now and will always be an info junkie.
I don't know what the facts are as far as tuneability on the Mopar ECU. It's my understanding that it won't tolerate a lot of deviation from stock. What are your experiences so far?

 

[twofosho]

So far what I've gotten from this thread is that most agree with me in general; that the Dodge TBI is crude, has less than stellar reliability, no four barrel versions were ever offered limiting you to the air flow of a two barrel, and aside from almost never failing to start, gives lousy performance, but that there are stalwarts here wanting to give it a go for many and various reasons of their own.

Chances are that before I dump the tons of money in my current pickup that it currently needs (as opposed to dumping that same amount of money in my Duster or '26 T), I'll probably buy a 10 year newer one with a Cummins. But saying that I did freshen it up and kept the TBI, it does seem logical to trash the Dodge Computer(s) and use a suitable GM ECM to run the Dodge throttle body and injectors. If someone came up with a harness allowing the GM ECM to plug and play, I'm sure they would be able to sell some here.

 

[66plyValiant]

So far what I've gotten from this thread is that most agree with me in general; that the Dodge TBI is crude, has less than stellar reliability, no four barrel versions were ever offered limiting you to the air flow of a two barrel, and aside from almost never failing to start, gives lousy performance, but that there are stalwarts here wanting to give it a go for many and various reasons of their own.

Chances are that before I dump the tons of money in my current pickup that it currently needs (as opposed to dumping that same amount of money in my Duster or '26 T), I'll probably buy a 10 year newer one with a Cummins. But saying that I did freshen it up and kept the TBI, it does seem logical to trash the Dodge Computer(s) and use a suitable GM ECM to run the Dodge throttle body and injectors. If someone came up with a harness allowing the GM ECM to plug and play, I'm sure they would be able to sell some here.

as said before I have more access to dodge TBI stuff cheaper, for the people who have a mild 318 or 360 it will work good, I'm not against GM TBI but at the moment I can't find the GM stuff to make a go of it anywheres cheaply, I would like to do a few GM TBI kits if I could find the parts as I love to learn and I love wiring as a challenge

 

[66plyValiant]

I'm interested in the how to guide for sure. I am now and will always be an info junkie.
I don't know what the facts are as far as tuneability on the Mopar ECU. It's my understanding that it won't tolerate a lot of deviation from stock. What are your experiences so far?

my experiences so far (from working on TBI dodge trucks) that a mild 318 can be fed from 360 injectors and the rest can mostly be kept 318 or the 360 computer can be used to up the air/fuel, 360 is abit more adaptable to change for whatever reason and takes to headers quite nicely and a few upgrades before it needs more fuel. I'm not aware of bigger injectors but that doesn't mean you can't get them but thats where modifying the vacuum singnal going to the fuel pressure regulator comes in,

the TBI regulators weren't prefectly preset at the factory so the pressure at the TB could be anywhere from 11.5-14.5 PSI although the pump at the rear is able to push 40 PSI open line pressure, we all know how much of a difference 3 PSI can make and that could be the anwser to adding more fuel to a "hotter" engine

 

[RustyRatRod]

For me, it would have to be cheap as a carburetor. Carburetors have come a LONG way and properly set up will perform almost as good as a TBI.

 

[66plyValiant]

For me, it would have to be cheap as a carburetor. Carburetors have come a LONG way and properly set up will perform almost as good as a TBI.

I agree carburators are great and I plan on keeping at least one of my vehicles stock with a carburator, with an electric fuel pump the work great but I thought I would try TBI and so far I'm liking it, no choke, no warm up time

 

[needsaresto]

Im sold on tbi myself. As I said before,the daily use thing has taught me that tbi is far more reliable than any carbed setup could every be.

 

[RustyRatRod]

Im sold on tbi myself. As I said before,the daily use thing has taught me that tbi is far more reliable than any carbed setup could every be.

If you really think that, then you've never had a properly set up carbureted fuel system. While a carburetor can never approach multi point EFI, they can certainly almost rival a TBI. EFI certinaly has its merits, but to say TBI is "far more reliable" than a properly set up and tuned carbureted system is just not true. The one and only point where TBI is consistantly better is warm up. With a good return system in place a modern HP carburetor is tough to beat. You sure will not catch me spending money on a TBI system. I would be interested in some sort of multi point system, but for me, it's not worth replacing good old faithful with a TBI. There's just not that much of a difference. People who say there is a night and day difference across the board between carburetors and TBI have probably never had a good carbureted system to begin with.

 

[needsaresto]

Not where I live Rob. I can go for a 10 minute drive and change elevation by more than 600 meters. That's about 1800 ft. You wanna see how a carb act's at 1600 mter's above sealevel when it's not tuned for it? Lol,tbi doesnt care whether it's sea level or the moon,your car will run the same.

Try that with a carb.

 

[xlexl]

After doing homework on my Jeeps OBD1 TBI system due to a possible 360 swap, I don't see Mopar TBI ever going on the Fish. The start ups are great advantage, but thats where it ends.
(1) Lack of aftermarket support, couldn't find any tuners available for reprogramming
(2) Related injectors for the system seem to be prone to issues, and replacing with larger is nearly impossible to find.
(3)The 2BBL throttle body is noticably a hinderance in a worn out 318, 4BBL TB I could only find from one company and it was the price of a new carb...which doesn't matter because your back to not being able to retune the tables for the increased airflow.
(4) The only option I found for changing the tables at all was either to send my ECM to a company I had never heard of before and pay with both testicles, right arm, and first born son. Or Mopar Performance, performance ecm(discontinued, of course) which really didn't accomplish much.

 

[needsaresto]

Oh 66plyValiant,your p.m box is full..

 

[66plyValiant]

Oh 66plyValiant,your p.m box is full..

all cleaned out, PM's are good to go now

 

[RustyRatRod]

Try that with a carb.

It's already been done for decades.

 

[slantsixdan]

Carburetors are a lot like breaker points: They work okeh immediately after you carefully set them up in accord with the driving and engine conditions, fuel composition, altitude, weather, etc., but they never work great and their condition starts degrading the moment you start the engine and they are unable to adapt to changes in any of those variables. Attempts were made to make carburetors adaptive (aneroid altitude compensators in the '70s, feedback mixture control with duty cycle solenoid and an O2 sensor in the '80s) -- these hideously complicated systems almost kinda sorta worked when they were brand new, until they (quickly) went out of whack and resisted all efforts at repair.

Just as even a basic electronic ignition is better than even a fancy dual-breaker points-condenser system, even low-endy TBI is better than a carburetor, because it's far more flexible and adaptive to all the variables encountered in normal driving.

 

[needsaresto]

I bet tbi would lend itself very well to a blow through turbo setup!

 

[66plyValiant]

I bet tbi would lend itself very well to a blow through turbo setup!

it would be best to run a digital air/fuel gauge if you were to do that so that you can keep a good eye on it, only thing I could see a problem is the Map sensor would have to be changed out for a 2 bar one or if your going crazy a 3 bar one, the factory one is 1 bar and is one of the reasons it doesn't take to major upgrades, having a fuel regulator that can handle boost is another way to ensure you don't lean out under boost.

as far as boosting goes I haven't done it with TBI and I didn't have immediate plans on trying it, the kit would be more for the N/A crowd at the moment and mild builds

 

[Revhendo]

I'm not sure I would try a turbo with a factory TBI. If you're going to that end, I would probably start looking at Multi or Sequential port injection. Most factory TBI systems weren't really intended for huge hp applications. They were more for commuter cars and trucks.
The Jeep guys are mainly all over the GM units because of the ease of adaptability and the increase in driveability. Trail driving tends to add in goofy angles and dramatic changes in altitude. (It's not unusual to see a Jeep going up a trail on a mountain and having the driver change the jets in his carb). I've heard some groans from the 4.0 crowd about the lack of user friendly tuning on the Mopar Performance injection conversion.

Is the pressure regulator on the Chrysler TBI unit itself? Is there a way to convert it to be adjustable?

 

[slantsixdan]

The fuel pressure regulator is bolted onto the throttle body itself, and while it is vacuum-sensitive (higher manifold vacuum = lower fuel pressure and vice-versa), it is not manually adjustable. I had a custom 21-22 lb regulator made as a part of one of my experiments trying to improve driveability and mileage. That experiment didn't work out, and I wound up going back to the stock 14 lb regulator.

 

[72DartSwingerV8]

I'm interested in the gas mileage improvements. Can anyone throw out some figures? Even if it is only 2 mpgs that's worth the $300-400 for this upgrade over the period of a couple months. Does EFI improve mileage a lot more than TBI or is it about the same? Just wondering about the details of this. Thanks for any info and good luck on making sales 66plyValiant!

 

[66plyValiant]

I'm interested in the gas mileage improvements. Can anyone throw out some figures? Even if it is only 2 mpgs that's worth the $300-400 for this upgrade over the period of a couple months. Does EFI improve mileage a lot more than TBI or is it about the same? Just wondering about the details of this. Thanks for any info and good luck on making sales 66plyValiant!

before the changeover the fifth avenue (car I did the change on) was averaging 20 canadian MPG. after the change I seen 23 MPG on the first tank and I ran a 1/4 tank through and rough calculated it to be about 23-24 MPG, mind you I haven't fully adjusted the timing perfectly (set around 12 BTDC and fuel pressure not checked yet) and I haven't had a chance to do any highway driving, most of my results were from the country roads I live on (mostly 45-50 MPH) it idles and starts much better then the carburator that was worn out ever did even when it was rebuilt, it seems to pull up hills better and I don't have to have my foot as far into it to do it. So far I would say it was worth it but I am going to do some more testing before I sell any harness's or complete kits

(I may sell one or two at the first as test muels for highway and city milage, and they will be highly discounted, buyer must be willing to work with me though and give MPG results)

 

[Revhendo]

Does the TBI ECU control spark advance?

 

[The Sasquach]

IMHO for what that's worth. For me and my purposes the debate is akin to, Anyone interested in ditching there point dizzy and going with a lean burn system. Yes TBI is an incremental step away from carbs, but it wasn't the best effort out there, and the system were discussing isn't the best of it's breed available. Technology moved away from it quickly, and in all honestly port injection is the logical step here. Since you have access to cheap parts and adapting to older vehicles is your goal, why not make and sell oem Mopar MPI conversions. I may be wrong but that would be more lucrative and in higher demand. David