Cali Smog Crap On My Motor...

[hick]

Howdy Folks,

I got my self an 89 CC dually with a 454 from Cali and looking to remove the smog stuff on it. I am posting here because although the motor and truck are an 89, its still in a square wrapper. Feel free to move this if some one sees fit

Now up here in the frozen north, the word "emissions" is damn near a swear word, so I never learned much about it, and with that said my mechanical knowledge is basic at best.

In pursuit of some hands on experience and some MPG, I am going to be doing a TBI rebuild this spring. Yes, I know, its a brick on wheels I and shouldn't have bought it for MPG... But I dont get over 3.5 MPG with it. It was a cool bragging point for awhile when the guys at the gas station stared seeing me twice in a day... but no more (PO even took the belt off the A/C compressor cause it was so bad). Yes, I have changed the fuel filter a few times.

To add salt to the wound, a friend of mine with an 80 some thing 4x4 CC dually is getting 10 MPG with a carb...

Now, will removing all the smog stuff screw with my TBI at all. Do I need to have any thing tuned or adjusted? I am only doing it because I figure I might as well

I have considered a whole new EFI system, but I am not interested in spending the money on a motor thats not staying. I am just a year or two away from doing a diesel swap.

It has also been suggested to switch over to a carb, but those i rely for usual mechanical input have VERY different opinions. One says for 1k I can get a good carb tuned and be further ahead MPG wise. The other says use what I have

If I cant fix this for 1000-1500 and some elbow grease, i'll just suck it up and be thankful I have the paycheck to support my habits.

Thanks for your time guys,

Scott

[mgchevyparts]

Some things wrong...those get 10-14 mpg all day down here in Calif

[hick]

hahaha your telling me... I was burning 140 in fuel a day for about 2 weeks

Some thing just occured to me while I was digging thread some other threads... Did these trucks have cats on them?

I know what they are and would recongize them, but other then the fuel filter I've never crawled under the truck (2wd and being fat)...

Cause the first fuel filter i removed i am POSITIVE was the OEM fuel filter... So If it has a cat i'm sure its plugged solid

[Zane M]

Yes, it does/should have a cat.
Smarter people than me will have to comment on the tuning/programming. I have to have all the emissions stuff where I live, so I have never researched the issue.

[mgchevyparts]

The original cat could cause your problem. Big blocks need free flowing exhaust. If you can legally remove it and add good headers with new exhaust you should pick up 3-4 mpg easily, and that's with replacing a non defective cat.

[rfmaster]

You should be getting at least 10 MPG unless you have another 6000 lb of lead in the bed -you would be getting about 9mpg. That being said there is not much as far as as smog related stuff on your 454.

First things first - TBI will you get you better fuel consumption then Carb under normal driving conditions. One of the possible reason why you are burning so much fuel is a broken or disconnected CTS. Some diagnostics are required. Luckily early TBI systems use SES light to indicate trouble codes without use of expensive scanner. All is required is an unfolded paper clip inserted into ALDL connector between terminals A & B to force ECM into diagnostic mode. Suggest that you download the following reference document:

http://www.73-87chevytrucks.com/tech...TBISystems.pdf

On Page 13 of the pdf file ALDL plug and codes are described on subsequent pages.


//RF

[hick]

Rfmaster, thank you very much for that.

Aftet a late night on the forum i have decided that i am going to rebuild the motor entirely as well as put in a 4l80e.

It needs a reseal bad and i figure if i am pulling the motor, why not do the tranny too. I am building it to be my summer DD

By my homework i can do all this for 6k, headers and exhaust included. That's spending a bit extra on the motor as well.

My numbers suggest this will pay for it self after 2 months of driving (i drive ALOT), so I feel its in my best interest.

I am paid EXTREMELY well to pull oil out of the ground, no sense in giving it all back to the oil companies haha.

Thanks all for your input, its much appreciated

Scott