Sensors In Truck??

Nccanes172000 · 03-05-2007, 05:34 PM

I Am Having The Following Problem...

I Have A 1991 Chevy S-10 Pickup, 2.8 V6, 2WD, Manual Transmission. I Am Really Getting Bad gas Mileage 7MPG. I Put A New O2 Sensor, Fuel Filter, Thermostat, Spark Plugs/Wires, Air Filter, And I Believe Thats It. I Would Like Any Info Why I Am Having This Problem. And I Would Also Like Maybe A Picture Or In Detail How To Change The Following Sensors/ETC.

1.) Mass Air Flow Sensor (MAF)
2.) Engine Control Temperature Sensor (ECT)
3.) Manifold Air Pressure Sensor (MAP)
4.) EGR Valve/Sensor

Now I Am Not Sure But Is The EGR Sensor Or The Valve The Same Or What. Or Any Of The Other Sensors.

THANKS

daman · 03-05-2007, 06:30 PM

MAF isn't a wear part really, they usally don't need chage unless it goes
bad(check engine light).

the engine temp sensor i like to change out,it's a two wire plug(black and yellow) usally around the front side of the engine and thermostat
housing.

Map is up to you i don't usally change that but probly not a bad idea.

EGR again not a bad idea i guess..

the egr , valve,( egr solenoid valve sends
vac to the egr)

Nccanes172000 · 03-05-2007, 07:57 PM

do you know where the other sensors are located. and by the way the truck has very little vacuum

daman · 03-06-2007, 05:27 AM

MAF should be in the air duck for the air breather

MAP will be a small box looking thing with a vacume hose and a plug
attached to it on the intake somwere.

EGR valve will be close to the EGR with a plug and two vac lines one
going to the EGR and one feeding the valve. you'll see it..

bradrhale · 03-06-2007, 06:12 AM

91 chevy didnt have a mass air flow sensor on it. is your check engine light on??

Chevy808 · 03-06-2007, 08:20 AM

Yeah, did you code?? I'm thinkin' EGR Valve/Sensor since you did just about everything else. But this would be guessing. Your "Check Engine" light would help a lot.

Nccanes172000 · 03-06-2007, 05:46 PM

well no engine light on. checked the egr its fine. and found a vacuum line that was crimped in two pales. replaces that. now could that have damaged anything that i have to replace. still getting bad gas mileage

dstrick32 · 03-06-2007, 06:11 PM

How many miles on the engine? The low vacuum would be cause for a compression and leak down test!!

Nccanes172000 · 03-07-2007, 05:20 AM

well it has 186,852. like i said i fixed a crimped vacuum line. but i think its more that that.

nnunez · 03-08-2007, 11:39 AM

i had a problem with my old s10 giving me about 10mpgs also. ........i changed the water temperature sending unit and it was fixed.

03-05-2007, 05:34 PM	#1
Nccanes172000 Junior Member Join Date: Mar 2007 Location: New Castle, PA Posts: 6	Sensors In Truck?? I Am Having The Following Problem... I Have A 1991 Chevy S-10 Pickup, 2.8 V6, 2WD, Manual Transmission. I Am Really Getting Bad gas Mileage 7MPG. I Put A New O2 Sensor, Fuel Filter, Thermostat, Spark Plugs/Wires, Air Filter, And I Believe Thats It. I Would Like Any Info Why I Am Having This Problem. And I Would Also Like Maybe A Picture Or In Detail How To Change The Following Sensors/ETC. 1.) Mass Air Flow Sensor (MAF) 2.) Engine Control Temperature Sensor (ECT) 3.) Manifold Air Pressure Sensor (MAP) 4.) EGR Valve/Sensor Now I Am Not Sure But Is The EGR Sensor Or The Valve The Same Or What. Or Any Of The Other Sensors. THANKS __________________ Eric Ritter

03-05-2007, 06:30 PM	#2
daman Full Member Join Date: Mar 2007 Location: Bad Axe, MI. Posts: 40	MAF isn't a wear part really, they usally don't need chage unless it goes bad(check engine light). the engine temp sensor i like to change out,it's a two wire plug(black and yellow) usally around the front side of the engine and thermostat housing. Map is up to you i don't usally change that but probly not a bad idea. EGR again not a bad idea i guess.. the egr , valve,( egr solenoid valve sends vac to the egr) __________________ 1999 1500 Z71 4x4 5.7 Vortec 3:73 posi LS Extended Cab Shortbed

03-05-2007, 07:57 PM	#3
Nccanes172000 Junior Member Join Date: Mar 2007 Location: New Castle, PA Posts: 6	do you know where the other sensors are located. and by the way the truck has very little vacuum __________________ Eric Ritter

03-06-2007, 05:27 AM	#4
daman Full Member Join Date: Mar 2007 Location: Bad Axe, MI. Posts: 40	MAF should be in the air duck for the air breather MAP will be a small box looking thing with a vacume hose and a plug attached to it on the intake somwere. EGR valve will be close to the EGR with a plug and two vac lines one going to the EGR and one feeding the valve. you'll see it.. __________________ 1999 1500 Z71 4x4 5.7 Vortec 3:73 posi LS Extended Cab Shortbed

03-06-2007, 08:20 AM	#6
Chevy808 Senior Member Join Date: Nov 2006 Location: Born & raised in Hawaii had to move to Salt Lake City...bummer Posts: 275	Yeah, did you code?? I'm thinkin' EGR Valve/Sensor since you did just about everything else. But this would be guessing. Your "Check Engine" light would help a lot. __________________ '85 Oldsmobile 442 '93 Chevy 2WD C1500 350 Silverado Extended Cab Shortbed '95 Chevy 4WD K2500 454 Silverado Extended Cab Long Bed

03-06-2007, 06:12 AM	#5
bradrhale Moderator Join Date: Apr 2006 Location: Texas Posts: 3,620	91 chevy didnt have a mass air flow sensor on it. is your check engine light on??

03-06-2007, 05:46 PM	#7
Nccanes172000 Junior Member Join Date: Mar 2007 Location: New Castle, PA Posts: 6	well no engine light on. checked the egr its fine. and found a vacuum line that was crimped in two pales. replaces that. now could that have damaged anything that i have to replace. still getting bad gas mileage __________________ Eric Ritter

03-06-2007, 06:11 PM	#8
dstrick32 Senior Member Join Date: Dec 2006 Location: Hilliard, FL Posts: 101	How many miles on the engine? The low vacuum would be cause for a compression and leak down test!! __________________ 95 Ford F-150XL 5.0 Automatic 92 Chevy Silverado 5.7 Automatic 94 Toyota Ex-Cab 4X4 3.0 Automatic

03-07-2007, 05:20 AM	#9
Nccanes172000 Junior Member Join Date: Mar 2007 Location: New Castle, PA Posts: 6	well it has 186,852. like i said i fixed a crimped vacuum line. but i think its more that that. __________________ Eric Ritter

03-08-2007, 11:39 AM	#10
nnunez Senior Member Join Date: Dec 2005 Posts: 307	i had a problem with my old s10 giving me about 10mpgs also. ........i changed the water temperature sending unit and it was fixed.

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