Basic TBI mod success

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Jppr26

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I'm almost thinking of just doing some exhaust and maybe a chip for now and possible building a mid range motor later on from collected parts, and just staying with a semi stock setup in this truck for now, as this motor, and truck could use a overhaul bit I dont have the time, money, or knowledge at this time
 

Rusty Nail

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191 is an earlier 193 head. Still a swirl port and certainly no better OR worse! than a 193...

Knowledge..I think comes in time. If you are kinda new here, or to working on cars and trucks in general -especially square bodies - or maybe you've been lurking for awhile and recently registered, this place has some terrific members that are willing to help you at no cost.

Willingness..
In my opinion is often times FAR more necessary AND desireable than overt knowledge.

If I may, sir.

In my experience with specifically squares and the GMSB I have found that simply observing and reading will yield very desireable results with time.

Stick around man.. Have a seat and make yourself at home, we're glad to have ya and you have a great lookin truck!

Absolutely nothing will happen remiss of willingness.

I guarantee it.

Q: How do you eat a whale?
A: One bite at a time.
 

4WDKC

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If you are dead set on this route here is your intake.

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lothar863

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Mine have mostly been early models, '88-'91 with no roller cams. They have all responded just as well as my '92 Camaro with roller cam.

Intake mods are very cheap. Timing is literally free. The exhaust is usually falling off with cracked manifolds due to age, so spending money on the exhaust often has to be done anyway when you buy one.

It's worth doing a little tinkering on them, because it goes a long way. It's not much work to get improved power, mpg and driveability.

Where should the timing be set?
 

bucket

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Factory calls for 0°. But 8-12° advanced works well for power and mpg. Before setting the timing, clean off the timing tab and make sure you can understand what the marks represent. Then fill in the TDC line on the balancer with white paint or a grease pencil, it makes it much easier to see when setting the timing. When setting the timing, you have to first disconnect the single-wire connector that's over by the brake booster area. It's a tan wire with a black tracer, and a weatherpack style connector. It will turn on the engine light with it disconnected, just ignore it.

Try setting the timing to 10° and then go for a drive. If you get pinging, set it back to 8°. If not, try for 12 and see if you can pull it off. The weather and engine condition will determine what you can get away with. But even a high-mile engine can normally run 12° BTDC with 89 octane.
 

Rusty Nail

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I'm at 9°.

The eBay dude sent me a 300-48 from a 300-66 listing...eBay buyer protection works!
Grr though.

The difference is perimeter or centerbolt heads...wtf you stupid assed seller? THIS AIN'T WHAT YOU LISTED, *********. :mad:
You... :flipthebird:

Slayer rulz!

xc_hide_links_from_guests_guests_error_hide_media

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Grr. A hunnert bucks was a steal...I should try to resell!

Who want it? N E buddy?
It's almost new, this pic sucks.
 
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gpmorgan

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I just recently installed a 92 tbi, that came out of my truck when it was new 102k miles, into my sons 97 Tahoe. Put a set of headman elite headers, under drive pulleys, electric fan, cast iron gm performance high rise intake, and get this, a 750 double pumper holley I had laying around. Woke that tbi up. Getting 16 mpg. Runs very good. Had to modify the 4 center bolt holes on the intake.

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Rusty Nail

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Improvement to my 30 year old TBI o.s. continues to occupy much thought.
It's my daily driver and I owe every dollar in my paycheck to operating that truck!

I happened into the linked website after realizing I am going to be forced to delete my EGR valve and will have to -probably should - "tune it out" with a different computer chip.

http://tbichips.com

I am searching for the best solution to do that and manage to find a TON of TBI info in the process. I consider the source(s) and don't take much of it too seriously (the internet) because ...I don't know them dudes and they are ALL trying to sell me SOMETHING!

It's pick and choose, take only what you can use, but I think from a very objective and skeptical standpoint there is a bunch of useful information found there.

I got hung up on the FUEL PUMP.
If I would have known a VORTEX pump would BOLT-IN , I sure as hell would have done so!
At least now I will have a VERY GOOD indicator of when I have reached a VERY decent power level. The TBI pump is only gonna support XX horsepower because it only flows XX amount of fuel and right this second needing (being forced) to upgrade to a different fuel pump IS.THE. goal.
 

Hatchet54

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191 is an earlier 193 head. Still a swirl port and certainly no better OR worse! than a 193...

Knowledge..I think comes in time. If you are kinda new here, or to working on cars and trucks in general -especially square bodies - or maybe you've been lurking for awhile and recently registered, this place has some terrific members that are willing to help you at no cost.

Willingness..
In my opinion is often times FAR more necessary AND desireable than overt knowledge.

If I may, sir.

In my experience with specifically squares and the GMSB I have found that simply observing and reading will yield very desireable results with time.

Stick around man.. Have a seat and make yourself at home, we're glad to have ya and you have a great lookin truck!

Absolutely nothing will happen remiss of willingness.

I guarantee it.

Q: How do you eat a whale?
A: One bite at a time.

I gotta say, I really love this post of yours, Rusty. Couldn't have said it better myself, and very inspiring.

Literally the exact thing that I'm doing right now...I'm getting absolutely absorbed into this thread and loving every post, despite the fact that I don't even have a tbi engine nor any type of desire to do any overhauling at all in the foreseeable future.
But regardless, this thread has me hooked, because knowledge and experience is never a bad thing down the road.

I was only ever a motorcycle mechanic in the past, and knew next to nothing about cars, let alone GMs, until I bought my square cold turkey. But between just sort of perusing around the truck every now and then and lurking on these forums and reading random threads like these, my confidence has already skyrocketed.

There was a time when I was a little overwhelmed, but like you said, once you get over the hump of becoming willing to learn, the rest sort of does itself.

Just a good post for anyone new here to read, kudos man, you're a gentleman and a scholar
 

Rusty Nail

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:waytogo:

Thank you sir, you are too kind. What else can I say? Everyone gets lucky once in a while! That leaves the bar awfully high - don't ya think? :uhoh2:

Moment of weakness?

LoL...
I believe that these old trucks are good for a great many things and this MSB has found a collection of some pretty awesome folks my dude, it has nothing to do with me - I just work here!

*edit*

When I was talking to Gary Camaro about an LT1 camshaft he suggested that I stick with a '93 or '94. Some jazz about how the OPTI-SPARK changed for the 1995 model year and there was some type of change on the camshaft too. Maybe a drive apparatus of some sort? Whatever it is, I agree with him.

There is no need to have unused rotating mass on the end of a camshaft.

The cam timing changed between 93 and 94, I believe ending to be more refined for 1994 and that is my choice. I will gamble that a 1994 LT1 camshaft will be THE hot ticket for my K5. I'll do it last and that will throw me over the fuel pump edge..
Specs on Stock TBI cam @ .050″ is 165/175 and lift with 1.5 rockers is .382/.402.

You must be registered for see images attach


I think that camshaft, the Corvette #113 heads, Holley 701r-48 intake, the headers and exhaust, plus THIS throttle body deal I want, will exceed the abilities of my brand new, AC DELCO, stock replacement, fuel pump and I aim to find out. Wouldn't that be somethin? The 58cc heads will bring my CR much closer to 1994 LT1 levels with no other changes. Everybody knows I support the "305 heads on a 350" swap and this build will be no different because it works.Good, when done correctly. I believe the use of aluminum heads over iron will eradicate the necessity for 91 octane PLUS i'll be able to tune it into the chip. ;) I consider dude's LS1 electric fans swap, great idea!
Isn't that enough?

https://www.ebay.com/itm/GM-TBI-por...-14cd-4178-b2aa-adf5f844b1da&epid=10023322039

You must be registered for see images attach


I'm finished. That is my TBI build plan, laid out before yous all.
For FREE.
With as many USED , OEM, STOCK parts as is possible.
Stock short block -made into a roller motor-, WITH the chip!
It's gonna kick YOUR truck's ass!
Lolololololol!

:burnout:

:flamingdevil:

xc_hide_links_from_guests_guests_error_hide_media

:High 5:


:driver:

Thanks to the OP for starting this thread.
 
Last edited:

4WDKC

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Improvement to my 30 year old TBI o.s. continues to occupy much thought.
It's my daily driver and I owe every dollar in my paycheck to operating that truck!

I happened into the linked website after realizing I am going to be forced to delete my EGR valve and will have to -probably should - "tune it out" with a different computer chip.

http://tbichips.com

I am searching for the best solution to do that and manage to find a TON of TBI info in the process. I consider the source(s) and don't take much of it too seriously (the internet) because ...I don't know them dudes and they are ALL trying to sell me SOMETHING!

It's pick and choose, take only what you can use, but I think from a very objective and skeptical standpoint there is a bunch of useful information found there.

I got hung up on the FUEL PUMP.
If I would have known a VORTEX pump would BOLT-IN , I sure as hell would have done so!
At least now I will have a VERY GOOD indicator of when I have reached a VERY decent power level. The TBI pump is only gonna support XX horsepower because it only flows XX amount of fuel and right this second needing (being forced) to upgrade to a different fuel pump IS.THE. goal.

TBI chips is great for specs and concepts for actual tuning he appears to be only worth a damn if you can get to his dyno. The mail order chips he does arent very good, google it...also known as Brian Harris...If you want to learn about TBI tuning use this site, its where I started.


http://www.gearhead-efi.com/Fuel-In...179-tbichips-com-(Brian-Harris)-Useful-or-Not



:waytogo:

Thank you sir, you are too kind. What else can I say? Everyone gets lucky once in a while! That leaves the bar awfully high - don't ya think? :uhoh2:

Moment of weakness?

LoL...
I believe that these old trucks are good for a great many things and this MSB has found a collection of some pretty awesome folks my dude, it has nothing to do with me - I just work here!

*edit*

When I was talking to Gary Camaro about an LT1 camshaft he suggested that I stick with a '93 or '94. Some jazz about how the OPTI-SPARK changed for the 1995 model year and there was some type of change on the camshaft too. Maybe a drive apparatus of some sort? Whatever it is, I agree with him.

There is no need to have unused rotating mass on the end of a camshaft.

The cam timing changed between 93 and 94, I believe ending to be more refined for 1994 and that is my choice. I will gamble that a 1994 LT1 camshaft will be THE hot ticket for my K5. I'll do it last and that will throw me over the fuel pump edge..
Specs on Stock TBI cam @ .050″ is 165/175 and lift with 1.5 rockers is .382/.402.

You must be registered for see images attach


I think that camshaft, the Corvette #113 heads, Holley 701r-48 intake, the headers and exhaust, plus THIS throttle body deal I want, will exceed the abilities of my brand new, AC DELCO, stock replacement, fuel pump and I aim to find out. Wouldn't that be somethin? The 58cc heads will bring my CR much closer to 1994 LT1 levels with no other changes. Everybody knows I support the "305 heads on a 350" swap and this build will be no different because it works.Good, when done correctly. I believe the use of aluminum heads over iron will eradicate the necessity for 91 octane PLUS i'll be able to tune it into the chip. ;) I consider dude's LS1 electric fans swap, great idea!
Isn't that enough?

https://www.ebay.com/itm/GM-TBI-por...-14cd-4178-b2aa-adf5f844b1da&epid=10023322039

You must be registered for see images attach


I'm finished. That is my TBI build plan, laid out before yous all.
For FREE.
With as many USED , OEM, STOCK parts as is possible.
Stock short block -made into a roller motor-, WITH the chip!
It's gonna kick YOUR truck's ass!
Lolololololol!

:burnout:

:flamingdevil:

xc_hide_links_from_guests_guests_error_hide_media

:High 5:


:driver:

Thanks to the OP for starting this thread.

95 Lt1 got the vented opti and is the one you want otherwise when the wp starts leaking the moisture that gets into the opti cant escape and it quits working. I read the 95 cam was the one you wanted if you couldnt get the stock lt4 cam. Here is a post where someone put it in his tbi 4x4 truck. He is also on gearhead-efi.com, I messaged him about it here is his response.
Woody80z28 said:
Well, I've actually been underwhelmed with that engine. Maybe my expectations were too high, but it hasn't been the torque monster I planned on. To be fair, the 1ton 5spd and the steel wheels both slow it down, and it is 5000lbs. But I expected more.

There are a couple of things that I would look into if the engine ever comes back out. One is the cam timing. I used a TPI chain and sprockets. I'd be curious to degree and see if it's advanced/straight/retarded on the cam dots.
I have also read that everyone hates TBI, but I do have the tune dialed in pretty well. Some swear to me a carburetor would make more power, but it's my winter beater, so there's no way I'm dropping fuel injection.
The other thing I would look at is the cam itself. Maybe a comp xtreme 4x4 or something would make more power. I will say that the LT1 cam is super smooth.

Hope this helps.

here is his build thread.

http://www.nastyz28.com/threads/cam-for-my-350-tbi-truck.214643/
 
Last edited:

bucket

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It took a few tries, but Brian did good with the tuning on my TPI Camaro. Other than an existing issue that nobody could figure out, driveability was great and mpg was good too.
 

Rusty Nail

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Dude!

I have been trying to read that thread all day and it was pretty good starting out..really went bad around page 7 I guess? I finally made it through page 10 and seems like it might be pickin back up lol.
Will advise.
 

4WDKC

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Dude!

I have been trying to read that thread all day and it was pretty good starting out..really went bad around page 7 I guess? I finally made it through page 10 and seems like it might be pickin back up lol.
Will advise.


I read it several times and followed up with his posts about tuning the truck also. I had the same plan for my truck till I spoke with him about it.
 

Rusty Nail

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Who is "him"? The OP?

Several times? **** I can't even manage once.

None of the pictures show lol I think that would have been more fun. I am glad to see all that talk about the LT1 cam and I like that site but rarely go there because I don't have the patience necessary. Kudos to you, if you do. Most of that stuff is ******** though. Just like the TBICHIPS site..there is SOME good stuff in there but I don't take it seriously.
 
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