Emissions issue

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach

Since I saw a couple of these just decided to add in all the other fuel gauge variations I saw
Canadian trucks didnt use E and F they used the circle thats hollow, the half line and then full white circle
Im guessing the gas pump was used in place of Fuel, just normally, and I do not believe they sold cat-trucks in canada, or canada used leaded gas longer than we did, so they wouldnt need to indicate unleaded only.
 

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
1,617
Reaction score
2,186
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
Yeah, the other truck [81] has unleaded on the gauge. My guess now is a bunch of parts have been swapped out or removed. It had some age before I got it.

It's a nice truck but eats gas like crazy.
 

Attachments

  • 100_0855.JPG
    100_0855.JPG
    176.3 KB · Views: 39

Royal Sierra 454

Full Access Member
Joined
Feb 3, 2022
Posts
268
Reaction score
651
Location
Goodyear, AZ.
First Name
Scott
Truck Year
1976
Truck Model
15 GMC Royal Sierra
Engine Size
454
My 1976 GMC C15 454. Fuel Guage and Vin. 6050 GVWR
 

Attachments

  • fuel guage.jpg
    fuel guage.jpg
    124.8 KB · Views: 42
  • vin.jpg
    vin.jpg
    82.4 KB · Views: 38

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
My 1976 GMC C15 454. Fuel Guage and Vin. 6050 GVWR
so I looked into it , fun facts:
1981 (at least) the 454 was only available with HD emissions(leaded fuel) so im guessing many big block trucks probably cane with HD emissions for years, explaining why the fuel restrictors/gas gauge things arent all that rare
but maybe it had to do with heat or hot spots + volatility + predet concerns they used leaded fuel longer?

also, 1981 trucks had an Off option on the HVAC fan but not a 1981 suburban :O @bucket fun fact on that lol, we talked about flow-thru ventilation before, figured you would find that interesting

The HD emissions engines also in 1981 were 50 state (california then too) 8600+
You must be registered for see images attach

this is from a suburban brochure. C2500 standard equipment was Leaded 5.7 but optional leaded 5.7 on K2500. Anyone remember if leaded gas when they both existed at the pumps if it was cheaper than unleaded? I cant discern how someone would want leaded gas engine by 1981 based on the power , but if it was like buying premium today I could see how a fuel chugging truck would have made sense to get unleaded

You must be registered for see images attach

Heres a 1981 truck. hd emissions 8600+ 50 states.
Also the 292 could not be had in unleaded, but the 250 couldnt be had leaded. I imagine canadian trucks with i6 must have been 292 then, unless they didnt ship engines from mexico to canada to put in and just used a v8 or had canadian only leaded 250s ;(
Also you have to appreciate the lower octane, unleaded 250 with 2 barrels was showing the 1 barrel higher octane(lower compression, longer stroke) 292 who was boss in power lol
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,087
Reaction score
23,882
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
'86 was the last year for non-cat trucks and Suburbans. Also, any truck that came with factory true dual exhaust did not get a cat.
 

peats

Full Access Member
Joined
Dec 2, 2016
Posts
289
Reaction score
236
Location
Pennsylvania
First Name
john
Truck Year
72k5, 81c10 short step, 83k10 short fleet, 03 SSR. 25 chevy doodlebug
Truck Model
k5 c10 k10 SSR doodlebug
Engine Size
406 360 6.2 5.3 171
Pretty sad that some states are dealing with emissions on a 40 something year old vehicle. Time to move on.
 

CRM

Full Access Member
Joined
Jun 6, 2016
Posts
1,188
Reaction score
2,775
Location
Pasco, Washington
First Name
Casey
Truck Year
1985
Truck Model
K2500
Engine Size
350 CI
While installing the Y pipe today, I found and removed a heat shield that appears to be the same size as a cat converter. I'll stick it on the spare parts shelf just in case I have to install a cat someday.
You must be registered for see images attach
 

CRM

Full Access Member
Joined
Jun 6, 2016
Posts
1,188
Reaction score
2,775
Location
Pasco, Washington
First Name
Casey
Truck Year
1985
Truck Model
K2500
Engine Size
350 CI
In preparation for installing new valve covers, gaskets, and EGR valve I pulled the EGR valve today. It's definitely the cause of some of my issues. Here's pics before cleaning and after cleaning. Before cleaning it the diaphragm would move but, because of the carbon build-up, nothing would pass through. It's getting replaced this next week but I decided to clean it and see what would happen. Night and day. It will go in my back-up box on the spare parts shelf. I also used a pick hook and vacuum to clean out the area in the intake below where it mounts.

You must be registered for see images attach
You must be registered for see images attach
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
if you have a zip tie the right size you could probably break up more further down the passage but good work
In preparation for installing new valve covers, gaskets, and EGR valve I pulled the EGR valve today. It's definitely the cause of some of my issues. Here's pics before cleaning and after cleaning. Before cleaning it the diaphragm would move but, because of the carbon build-up, nothing would pass through. It's getting replaced this next week but I decided to clean it and see what would happen. Night and day. It will go in my back-up box on the spare parts shelf. I also used a pick hook and vacuum to clean out the area in the intake below where it mounts.

You must be registered for see images attach
You must be registered for see images attach
 

rpcraft

Full Access Member
Joined
May 31, 2016
Posts
1,329
Reaction score
509
Location
Texas
First Name
Robert
Truck Year
1985
Truck Model
Jimmy
Engine Size
LS 6.0 364 CID
Good to know. I really had no idea non-cat was an option so late into the 80's.


I am a little late to the party but in many states HD trucks (20 and 30 series) were usually smog exempt so one thing to consider.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
10,118
Reaction score
14,382
Location
Right where I am
First Name
Bagoomba
Truck Year
1981, 1965
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
Engine Size
Carb'ed Vortec 350; 1972 L48 350
I am a little late to the party but in many states HD trucks (20 and 30 series) were usually smog exempt so one thing to consider.
Unfortunately not here, but much easier to get to pass than a C10.
 

Latest posts

Forum statistics

Threads
42,065
Posts
908,307
Members
33,542
Latest member
willyg
Top