Author Topic: 87 k10 350 tbi tuning?  (Read 6790 times)

Offline buzzman351

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87 k10 350 tbi tuning?
« on: September 30, 2022, 06:17:45 AM »
I have set timing, replaced map, coolant sensor, egr, pcv, plugs, wires. the list goes on. it runs good but honestly id like for a mechanic to hook it up to a diagnostic machine and tune it or whatever needs to be done. is that possible?

Offline VileZambonie

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Re: 87 k10 350 tbi tuning?
« Reply #1 on: September 30, 2022, 07:30:27 PM »
As long as you find someone who knows what they're doing..... Not many left
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline JohnnyPopper

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Re: 87 k10 350 tbi tuning?
« Reply #2 on: September 30, 2022, 09:34:08 PM »
I feel really ignorant, being the owner of a '89 R30 with TBI that doesn't run, due to code 44.

Is there a diagnostic tool that tunes the fuel delivery system?

Sooner or later I will have to dive into this head long, in the meantime any peripheral info would be appreciated... ;)
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline buzzman351

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Re: 87 k10 350 tbi tuning?
« Reply #3 on: October 01, 2022, 04:54:34 AM »
i am no expert by any means. i just search the internet, talk to friends and post here but it says code 44 is lean mixture..does the truck run at all?

Offline VileZambonie

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Re: 87 k10 350 tbi tuning?
« Reply #4 on: October 01, 2022, 07:02:43 AM »
First thing to do is get a fuel pressure gauge on there. You can tee in by removing the fuel filter or by adding a test port.
,                           ___ 
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              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline JohnnyPopper

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Re: 87 k10 350 tbi tuning?
« Reply #5 on: October 01, 2022, 11:16:02 AM »
Not what I would call 'running', I have to feather the pedal to keep it running. I shot a video of intermittent gas coming out of the injectors.

Re: 44, I recall it saying that the O2 sensor should be replaced.

I fired the parts cannon of new filter and temp sensor.

Cleaned up some ground points.

She went from nothing to the feather routine.

I'll get the gauge on next. Any brand you recommend VZ?
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline VileZambonie

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Re: 87 k10 350 tbi tuning?
« Reply #6 on: October 01, 2022, 06:27:42 PM »
You can pretty much get anywhere
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline JohnnyPopper

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Re: 87 k10 350 tbi tuning?
« Reply #7 on: October 04, 2022, 04:28:41 PM »
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bd

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Re: 87 k10 350 tbi tuning?
« Reply #8 on: October 04, 2022, 05:49:10 PM »
FYI - Although better than no gauge at all, that's not the best gauge for TBI.  GM TBI only runs about 12 PSI.  It is better to rely on a gauge with the target pressure roughly mid-scale if possible (e.g., 20 - 30 PSI full-scale calibration).
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline JohnnyPopper

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Re: 87 k10 350 tbi tuning?
« Reply #9 on: October 04, 2022, 08:12:21 PM »
Thanks, makes sense.  ::)

Maybe I can swap out the gauge head. I'll look at the A/C kit I have.

All the other parts made it look like it would be easy to use.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bd

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Re: 87 k10 350 tbi tuning?
« Reply #10 on: October 04, 2022, 10:36:57 PM »
I've accumulated various gauge heads over the years and interchange them as necessary.  That set looks like it has everything you'll need to tap in at the framerail-mounted fuel filter.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline JohnnyPopper

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Re: 87 k10 350 tbi tuning?
« Reply #11 on: October 04, 2022, 11:39:26 PM »
Thanks bd, I was hoping that I could find a place under the hood.

1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bd

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Re: 87 k10 350 tbi tuning?
« Reply #12 on: October 05, 2022, 01:49:43 PM »
You should be able to do that with some head scratching and thoughtful planning.  The fuel lines are firmly clamped to the rear of the right cylinder head and are tedious to access.  Still, with the correct adaptor, you can tap into the pressure line at the back of the throttle body after you unclamp the lines from the head and move the ignition coil out of the way.  To alleviate future effort, you might consider installing a permanent pressure tap in a more convenient location.  Otherwise, tapping pressure at the fuel filter is not difficult.  Once you figure it out and learn how to keep fuel out of your eyes and armpits it becomes fairly routine.   8)
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline ehjorten

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-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline 1980K20

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Re: 87 k10 350 tbi tuning?
« Reply #14 on: October 09, 2022, 01:26:05 AM »
I was told during my efi adventure that when the o2 sensor fails, it reads full lean and the system runs very rich.  You can probably tell from pulling a plug, rear was worst on mine.


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1952 International L112 - waiting for EV conversion
1967 Camaro - 250 six cyl, 200-4R
1980 K20 4x4 Fleetside - 350 SBC roller Cam, TH350