Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
|
04-13-2021, 01:59 AM | #1 |
Registered User
Join Date: Apr 2003
Location: Indep, MO
Posts: 5,893
|
TBI Info down on power
I just bought my 87 GMC 350/350 TBI back after 5 years. Still in good shape, but on the 120 mile run home, I noticed it being down on power. Still seems to run ok, but it had a lot more snap when I had it. Pulling up the hill to the house, I had my foot way into it, and Buuuuuuhhhhhh, no power. I'm assuming weak fuel pump/bad injector. Any other thoughts? Thanks!
__________________
Boppa's Old Yeller Truck Build, Old Yeller's New Heart! Project Buzz Bomb Flyin' Low! |
04-13-2021, 12:57 PM | #2 |
Senior Member
Join Date: Dec 2011
Location: Moraga, CA
Posts: 809
|
Re: TBI Info down on power
Fuel filter(s) might be the quicker easier thing to check.
Then look at your spark plugs. Then check compression. And do your normal maintenance/tune-up things in between as you go.
__________________
(Very) Slow-Going Build Thread: Stock 1970 Short Step with Stock 1970 LT-1 http://67-72chevytrucks.com/vboard/s...d.php?t=567340 Last edited by mattfranklin; 04-13-2021 at 01:02 PM. |
04-13-2021, 03:09 PM | #3 | |
The Older Generation
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 25,370
|
Re: TBI Info down on power
Quote:
Like Matt said could be a plugged filter (fuel or air). I can't think what they had for filters. I guess it could be bad plugs or timing off too. LockDoc
__________________
Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
|
04-13-2021, 05:35 PM | #4 |
Registered User
Join Date: Apr 2003
Location: Indep, MO
Posts: 5,893
|
Re: TBI Info down on power
This is all in the plan, Stacked up pretty tall for the next couple weeks, Has a filthy K&N on it now, and lord knows when the fuel filter was changed. Didn't seem to be misfiring. Has good Oil Pressure. They just put a cap on it and said it made a big difference. I might stick some plugs in it too. Planning on an LS this winter, so I just need it up to fun bombin' for the summer.
__________________
Boppa's Old Yeller Truck Build, Old Yeller's New Heart! Project Buzz Bomb Flyin' Low! |
04-13-2021, 09:02 PM | #5 |
Senior Member
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,412
|
Re: TBI Info down on power
Plugged muffler, catalytic convertor
|
04-14-2021, 10:17 PM | #6 |
Registered User
Join Date: Apr 2003
Location: Indep, MO
Posts: 5,893
|
Re: TBI Info down on power
Big ol Flowmaster, don't think it has a cat. I've had that before, feels like it's "huffing" into it.
This is more everything's opening, and nuthin's happening. Like it's waiting for something.
__________________
Boppa's Old Yeller Truck Build, Old Yeller's New Heart! Project Buzz Bomb Flyin' Low! |
04-13-2021, 11:04 PM | #7 |
Registered User
Join Date: Jan 2003
Location: Safford,AZ
Posts: 3,613
|
Re: TBI Info down on power
|
04-14-2021, 11:08 AM | #8 | ||
"I ain't nobody, dork."
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,921
|
Re: TBI Info down on power
A hundred years ago, I owned a '91 K2500 Suburban with a TBI 350 in it. Down on power and I checked or replaced everything I could think of. Fuel filter, fuel lines, fuel pump were all good. No trash in the tank, and everything else was pretty mechanically sound. Distributor and coil were good. New plugs and wires didn't help either. Total head scratcher.
Ended up being a faulty injector wire harness ($10 dollar part) where it plugs in to the injectors. Easy fix and made all the difference in the world. Gary
__________________
'cuz chicks dig scars... My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread. The Rebuild of Creeping Death after the wreck Quote:
Quote:
|
||
04-14-2021, 10:04 PM | #9 |
Registered User
Join Date: Apr 2003
Location: Indep, MO
Posts: 5,893
|
Re: TBI Info down on power
Hmm! Thanks for the tips, I'll give it a try!
__________________
Boppa's Old Yeller Truck Build, Old Yeller's New Heart! Project Buzz Bomb Flyin' Low! |
04-19-2021, 09:02 AM | #10 |
Watch out for your cornhole !
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
|
Re: TBI Info down on power
Put a timing light on it. Retarded timing from the distributor slipping will present exactly how you describe. Don't forget to unplug the little wire when you check/adjust it.
__________________
I'm on the Instagram- @Gearhead_Kevin |
04-24-2021, 07:53 AM | #11 |
Registered User
Join Date: Jul 2014
Location: North-central Virginia
Posts: 1,099
|
Re: TBI Info down on power
The tbi engines used flat tappets, and were notorious for wiping off the cam lobes. This could explain a lack of power.
__________________
1987 C6P V20 truck, 2010 LMG 5.3, AFM delete, 2010 Camaro exhaust manifolds, 1997 nv4500, 1991 np241c, hydroboost, 2005 14bff axle & driveshaft, drop-n-lock gooseneck, 4.10 gears, stock suspension, rims, and tires. Still a work in progress. Any questions or suggestions are welcome! |
05-03-2021, 07:22 PM | #12 |
Registered User
Join Date: Apr 2003
Location: Indep, MO
Posts: 5,893
|
Re: TBI Info down on power
Finally got a bunch of boat stuff out of the way, hoping to take a look this weekend. Glad to see you around, Kevin!
__________________
Boppa's Old Yeller Truck Build, Old Yeller's New Heart! Project Buzz Bomb Flyin' Low! |
Bookmarks |
|
|