91 350 TBI Engine maintenance.

[PlayingWithTBI]

Okay then is there any way to add some HP to the TBI?

Pretty much the same way you do with any motor, you get it to breathe better, from top to tail pipe. Depending on how much HP you want and how big of a budget you have will dictate what course you can take.

 

[kenh]

Okay then is there any way to add some HP to the TBI?

As said.... Start with exhaust. Headers, mufflers and tail pipe. Then get some air in. Cold air intake?? then cam, lifters and possibly 1.6 rockers. If your block has provisions for a roller cam then DO go that route. If for nothing else the oil these days does not really support flat tapped cams. And it certainly won't in the future. New timing chain and sprockets is also a must and if possible, degree the cam to confirm it is correct.

With all the above said it will be necessary to burn a new chip to take advantage of all the upgrades.

Ken

 

[Ds9Defiant1701]

Almost sounds like i should change the block to a younger one since mine almost got 300k km on it and it might not support a boost. I already need a new exhaust since it got a hole in it and it sounds good but i don't want a ticket for it lmao.

 

[1989GMCSIERRA]

Okay then is there any way to add some HP to the TBI?

yes you can make hp with TBI

my suggestion is....get the vehicle running right by doing all the maintenance first. Make sure your drivetrain is stout enough to add the hp. Remember it’s a older truck with higher miles and most likely original drivetrain. So you start adding hp you’ll most likely find out what is the weak link in your drivetrain and as you fix it you’ll stress out other parts until you fix all the weak links.. your block is fine. As long as it’s not cracked it’s actually better as it’s gibe through heat cycles. You ca d9 the typical 383 build roller cam/rockets Edelbrock intake abd bore the TBI get a chip burned and that will give you a bunch of torque and up the hp. You’re not gonna have 400 hp but it should be a nice solid runner. you can akeays swap with a LS

there are engine modifications, heads, intakes, TBI mods. And you can do pretty much every engine trick for a 350 chevy that there is like bore stroke polish. Lots of people don’t like TBI. personally i feel is a great simple reliable fuel injection that works without breaking the bank.


As far as the transmission a drain and fill is fine. I’ve changed the fluid on all my transmissions with drain, filter and fill. Never had a issue.

the plug wires and coil....the factory replacement stuff will be fine. You’re not running a dragster engine. My advice to you..get the truck running right, enjoy a dependable truck you can daily drive

 

[LVJJJ]

I agree with Erik the Auwful, use only AC plugs, also wires and everything else. I had my 94 repaired by a local mechanic who used to be a teacher at a GM truck manufacturing plant so really knew his stuff. he said use only AC Delco parts for your ignition. I found out that is true, when i bought the one owner always garaged GMC Suburban creampuff at 129,000 miles, I found out that while the original owner kept all the fluids fresh, he never changed any of the plugs or wires. so got myself some fancy stuff from NAPA but it didn't run all that great and even had one of their lifetime wires short out against the spark plug protector. Changed everything to AC and it runs great.

 

[LVJJJ]

Also, keep the TBI. You can get the injectors cleaned by a guy in Idaho, which really helped. If you're interested I'll try to find his number and address.

 

[PlayingWithTBI]

You can get the injectors cleaned by a guy in Idaho, which really helped. If you're interested I'll try to find his number and address.

Are you thinking of Mr Injector? He's pretty much the go to guy for these.
https://www.mrinjector.us/contact-us.html

 

[tsr2185]

Are you thinking of Mr Injector? He's pretty much the go to guy for these.
https://www.mrinjector.us/contact-us.html

Is this a better alternative to get stock injectors cleaned, instead to buying new AC delco ones?

Im thinking of a TBI rebuild in the future, my spray pattern isnt 100%.

thanks

 

[PlayingWithTBI]

Is this a better alternative to get stock injectors cleaned, instead to buying new AC delco ones?

These TBI injectors are known to be +/- 10% of flow rating from the factory. It's best to get "flow matched" ones, then you can dial them in with an AFPR (Adjustable Fuel Pressure Regulator). There are vendors that can give you flow matched ones.

Or you could send in your TB and have it bored, 1/4" spacer added, plus "Ultimate Mods" done.
http://www.rvmorsemachine.com/product.htm

 

[Trlrider]

Use quality spark plug wires. Ideally you want 8mm wire or better. Fortunately our trucks are so common that you can get quality wires dirt cheap. https://www.rockauto.com/en/moreinfo.php?pk=871633&cc=1031230&jsn=528&jsn=528


Here's your cheat sheet for which plug brand to buy based on the type of vehicle:
GM - AC Delco
Ford - Autolite
Chrysler - Champion
Japanese - NGK or Nippondenso
German - Bosch

Note that NGKs also seem to do well in GMs.

Agree on the NGK's! Have been using them for over 20 years since on of our sponsors started supplying them for us to use. Even had a NGK rep spend some time with us at a couple of races.
Have never had a complaint and that is what is in both my '93 Suburban project and my '04 Avalanche!