Author Topic: Carb to TBI conversion  (Read 22279 times)

Offline LTZ C20

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Carb to TBI conversion
« on: August 11, 2014, 10:04:22 PM »
Hey all, I am considering going to TBI. My carb is not working well with my engine. It works pretty good when the engine is hot but, not so well when colder. The engine is not very air conditioning friendly.  I would need a throttle solenoid to compensate for idle.

Also I'm pretty much the only one who can drive it. When it buggers out I know what to do. However, if my girlfriend or mom would need it, they wouldn't know what to do if it had a spaz moment.

The engine will sometimes die, either coming to a stop or just off from stop. I have spent a total of 5 calls and 2 hours on the phone with Holley trying to rectify these issues, along with a dieseling and floating idle problem.

After many discussions with holley, friends and an old school drag racer, I think it's in my best idea to go TBI. So here I would like suggestions for systems, curtain brands to look at and stay away from. I'm on a somewhat of a budget here also. So systems are too expensive, others are easily do-able.

I just want to make sure I make a good and reliable choice if I'm going to spend this much money again on this new engine.

So here is what I have found:

-FAST makes a nice system. It's the EZ-EFI system. A little over my budget but seems to be a very good candidate.

http://m.summitracing.com/parts/fst-30227-kit

-Howell Engine Development makes a very nice system that is also in my budget. This is what the old racer recommended I get. He said he has installed a few of these systems, they work good and he likes them.

https://howellefi.com/tbi-kit-universal-v-8.html

So tell me what you think? Have you guys used any other affordable systems that work good with mild performance street engines?

The Howell system appears to be friendly with my existing intake and distributor also. I would like to try and stay away from changing my intake and distributor. Keep the cost down and still be the engine I set out to build. I'm leaning toward the Howell. I have looked at other setups, most are far beyond my ability. Budget is about 1500, so please be kind to my wallet haha.

Here are some other articles I found while researching.

http://www.hotrod.com/techarticles/engine/hrdp_9812_carburetor_to_tbi_conversion/

http://news.pickuptrucks.com/2013/04/quick-install-efi-on-any-older-pickup.html

Thanks in advance for all input and suggestions!!
LTZ Cheyenne C20

Offline roundhouse

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Carb to TBI conversion
« Reply #1 on: August 12, 2014, 06:39:36 AM »
We just tossed a Edlebrock and installed TBI

We purchased a TBI system from a 1990 model pickup
And got to hear it run before we pulled it
(seller had no antifreeze last winter.  Cracked block )

Took about two hours to pull everything
Guy said for $200 we could take any thing we wanted from truck

We spent an addl $300 or so for the adapter plate , inline pump ,filters ,hoses  relays etc

The system is the same for 305 and 350  just different injectors in the TBI unit
The 305 is very common

I think
The system from a v6 will work also just by swapping injectors
« Last Edit: August 12, 2014, 06:41:22 AM by roundhouse »

Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #2 on: August 12, 2014, 01:56:40 PM »
Yes I have heard about that. It sounds relatively cheap and easy and reliable.

I actually called the Howell place today to question them about there system. They asked me about my heads, cam and such. They said they can include a heated O2 sensor, ac and transmission TCC lock up. If something isn't quiet right, I should call them and they burn a new chip and send it to you for free. Very nice system, very adaptable and easy to repair if needed.
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Offline Captkaos

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Re: Carb to TBI conversion
« Reply #3 on: August 17, 2014, 01:01:26 PM »
I would choose  the Howell it is the GM setup just wired stand alone.

I pulled the wiring and TBI stuff off a motor that I think I still have.

Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #4 on: August 17, 2014, 09:20:22 PM »
I ended up going with the Howell kit. I ordered it on Friday and should be here Thursday or Friday of this week. I will write up a full build on the install.
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Offline bake74

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Re: Carb to TBI conversion
« Reply #5 on: August 17, 2014, 09:36:00 PM »
I ended up going with the Howell kit. I ordered it on Friday and should be here Thursday or Friday of this week. I will write up a full build on the install.

     Interested on seeing how this goes LTZ C20.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #6 on: August 17, 2014, 10:50:20 PM »
I've been doin alot of research. As far as I have found, it's supposed to be able to do in one day. It's supposed to be very easy and a well built kit. It's reliable and pays for itself in fuel savings alone. I guess we find out.

Here's what I got:
-Howell universal TBI conversion kit. This one is for the big block. They recommended this one because it's a 670 cfm and would be more efficient with my very non stock engine haha.

-heated oxygen sensor,  recommended for vehicles with headers and dual exhuast.

-I also got them to add some extra wiring my air conditioning and trans TCC.

-Howell's mechanical to electric speed sensor converter. Mounts inline with the speedo cable, either between the 2 cable halves or right at the tail shaft cable mount on the transmission itself. Needed for for TCC.

And after asking my about almost every part of my engine, they are sending a custom chip. They say if it's not right or needs something, call, they will burn another modified chip and send it to me for free.

I have to say the customer service was excelllent, salesman was very knowledgeable and helpful and the receptionist was very kind and curtious. So for very impressed with the company. All in total cost was just over $1600 and they covered the shipping for me. :D
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Offline Captkaos

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Re: Carb to TBI conversion
« Reply #7 on: August 17, 2014, 11:31:59 PM »
You made a good choice.  A few places I know locally use their stuff.

Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #8 on: August 18, 2014, 12:50:40 AM »
Excellent! Another good review! I honestly can't wait to do this. I'm planning on doin the swap this weekend.
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Offline Captkaos

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Re: Carb to TBI conversion
« Reply #9 on: August 18, 2014, 07:19:57 AM »
take pics, notes and pass it on..

Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #10 on: August 18, 2014, 09:53:43 AM »
Oh don't worry there will be plenty of that.
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Offline mike657894

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Re: Carb to TBI conversion
« Reply #11 on: December 18, 2014, 04:32:25 AM »
hows the power? i had a few 88s didnt like how slow they seemed in mid range currently drive a 78 350/350 4x4 and love it had problems like you were talking about. dieseling is because of too rich of mixture. and the other stuff sounds like vacuum problems. i am using a stock qaudra jet. i eliminated most of the vac lines with caps and took the advance line from the intake it was going off the carb and i think that was most of my problem. now it seems way faster than my tbis were. but i had those when they were old and tired and i was not as handy 10 years ago. any plans to dyno it?

Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #12 on: December 18, 2014, 08:46:20 AM »
I have been using the TBI kit for a few months now and it has been EXCELLENT.  Fuel milage is WAYYY better than it was with carb, especially because I can lock up the torque converter with the computer too. That's sooo nice. The power is awesome, runs great, sounds freaking amazing and I can use my new A/C!

I have my notes and pics for doing a build thread, just been so busy and every since the Tapatalk app did it's first update like a month ago I can't upload pics anymore, so I'll have to put them all on the computer and do my right up there.

Only problem I've been having is my throttle cable is 2 long and old and stretched and I can only get the motor up to 1/2 throttle when I floor it. I was gonna get the throttle cable from a 80s square body with the TBI but then found out that cable is longer than mine and would only make the problem worse. Oh well, I'll get it fixed one day, for now it stops me from really getting that thing any faster than 3000 rpm,  helps save on gas haha.  Other than that the kit was well worth it.

I had a lot of problems and didn't know that when I built the engine I accidently built one that didn't like carbs, no heat exchange in the heads or intake. So fuel injection it was and has been totally the best.
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Offline Irish_Alley

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Re: Carb to TBI conversion
« Reply #13 on: December 18, 2014, 12:46:05 PM »
the cable length wont a part of how much throttle you give it. if you pull the cable 3" on the gas pedal side it has to pull 3" on the tbi side. the only thing you can do is relocate the mounting point on the tbi. take a picture
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Offline LTZ C20

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Re: Carb to TBI conversion
« Reply #14 on: December 18, 2014, 02:30:02 PM »
I've tried to find a good place to move the bracket but can't. Not with my setup. I've got a big loop like a roller coaster in the cable and I tired to bend the pedal bar more for more travel but that didn't work either. Probably just gonna get a new pedal assembly and shorten the cable.
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