Carb and gas mileage ???? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

red71cheyenne · 08-26-2006, 06:40 PM

Junior bought an 85 S-10 Blazer a little while ago. It seems to like going thru gas a lot. I have heard that there was a problem with them doing that for this year. Anyone know of a cure for it? He has the 2.8L V-6 engine. Seems to be in fairly decent shape. I did have to replace the intake gaskets and one of the head gaskets. Both were leaking oil pretty bad. I also removed all his smog crap. Any input would be great! Thanks, Jeff.

red71cheyenne · 08-29-2006, 08:04 PM

ttt???

Prerunner1982 · 08-30-2006, 09:28 AM

A carb rebuild may be in order.

79Silv4x4 · 08-30-2006, 11:49 AM

If it's like my '83 was it has the vari-jet (I think that's what it was called) and not everyone can rebuild them correctly. I got about 23-25 mpg out of my '83--it was a 4WD pickup though.

red71cheyenne · 08-30-2006, 08:43 PM

This one is a 2WD. The carb is a one barrel. There is some kind of wierd electrical plug on it as well though. There is a grating looking thing in the manifold gasket for it that plugs into the wiring harness. Any idea what that is? I'll try to rebuild it as well. I haven't had much luck with that though. All my Rochesters never worked much better after the rebuild. Thanks, Jeff.

84 400 · 08-30-2006, 08:49 PM

i am not sure on that issue. they should start an s10 style section for that style trucks and blazers

red71cheyenne · 09-01-2006, 10:19 PM

Just got the LMC catalog for it in the mail. The gasket with the waffle board in it is called EFE. Early Fuel injection or some such nonsense. Although its a one barrel carb, not FI. Strange setup. Thanks, Jeff.

lilpup69chevy · 09-01-2006, 10:22 PM

you know when you take off the smog stuff you have to readjust the timing since the load of the smog pump is not on it right??? or atleast thats what i have always heard don't know if it would make a difference or not could be a bad carb, also those 2.8's were known for having main bearing problems

piecesparts · 09-01-2006, 11:04 PM

I am thinking that is a little strange. The timing is not affected by the load on the belts from the extra equipment. The timing is set internally and all of the stuff on the outside is just drag to the whole motor's operation. With the smog stuff gone, there will be a difference in what the motor sees as a burnable mixture in the intake and the exhaust system. the smog pump will not be adding air to complete the burn on the gas loaded exhaust gases and the EGR valve is blocked off (isn't it???) so that there is no longer a heated exhaust gas gong to the intake. The catalytic converters have been removed (haven't they), if not they could be causing some operational problems, without the air injection. The fuel consumption is probably due to a bad carb or a vacuum leak.

08-26-2006, 06:40 PM	#1
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Carb and gas mileage ???? Junior bought an 85 S-10 Blazer a little while ago. It seems to like going thru gas a lot. I have heard that there was a problem with them doing that for this year. Anyone know of a cure for it? He has the 2.8L V-6 engine. Seems to be in fairly decent shape. I did have to replace the intake gaskets and one of the head gaskets. Both were leaking oil pretty bad. I also removed all his smog crap. Any input would be great! Thanks, Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

08-29-2006, 08:04 PM	#2
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Re: Carb and gas mileage ???? ttt??? __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

08-30-2006, 09:28 AM	#3
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	Re: Carb and gas mileage ???? A carb rebuild may be in order. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

08-30-2006, 11:49 AM	#4
79Silv4x4 Workaholic Join Date: Oct 2002 Location: Katy, TX Posts: 1,589	Re: Carb and gas mileage ???? If it's like my '83 was it has the vari-jet (I think that's what it was called) and not everyone can rebuild them correctly. I got about 23-25 mpg out of my '83--it was a 4WD pickup though.

08-30-2006, 08:43 PM	#5
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Re: Carb and gas mileage ???? This one is a 2WD. The carb is a one barrel. There is some kind of wierd electrical plug on it as well though. There is a grating looking thing in the manifold gasket for it that plugs into the wiring harness. Any idea what that is? I'll try to rebuild it as well. I haven't had much luck with that though. All my Rochesters never worked much better after the rebuild. Thanks, Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

08-30-2006, 08:49 PM	#6
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: Carb and gas mileage ???? i am not sure on that issue. they should start an s10 style section for that style trucks and blazers __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out

09-01-2006, 10:19 PM	#7
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Re: Carb and gas mileage ???? Just got the LMC catalog for it in the mail. The gasket with the waffle board in it is called EFE. Early Fuel injection or some such nonsense. Although its a one barrel carb, not FI. Strange setup. Thanks, Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

09-01-2006, 10:22 PM	#8
lilpup69chevy 67-72 parts finder Join Date: Aug 2006 Location: southeast mo Posts: 788	Re: Carb and gas mileage ???? you know when you take off the smog stuff you have to readjust the timing since the load of the smog pump is not on it right??? or atleast thats what i have always heard don't know if it would make a difference or not could be a bad carb, also those 2.8's were known for having main bearing problems __________________ 1969 chevy shortstep 2wd (under construction) 1981 chevy scottsdale lwb 2wd (parts chaser) 2004 pontiac gto (daily driver) 2004 pontiac grand prix gt (the ol ladys car) 1985 chevy short wide 1970 chevy c10 lwb (another parts rig) 1969 gmc lwb (rainy day project) 1968 chevy lwb c10 250 I6 3 spd (soon to be swb)

09-01-2006, 11:04 PM	#9
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Carb and gas mileage ???? I am thinking that is a little strange. The timing is not affected by the load on the belts from the extra equipment. The timing is set internally and all of the stuff on the outside is just drag to the whole motor's operation. With the smog stuff gone, there will be a difference in what the motor sees as a burnable mixture in the intake and the exhaust system. the smog pump will not be adding air to complete the burn on the gas loaded exhaust gases and the EGR valve is blocked off (isn't it???) so that there is no longer a heated exhaust gas gong to the intake. The catalytic converters have been removed (haven't they), if not they could be causing some operational problems, without the air injection. The fuel consumption is probably due to a bad carb or a vacuum leak.



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