4.3 excessive fuel use

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KyleS15
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4.3 excessive fuel use

Postby KyleS15 » Wed Feb 29, 2012 1:46 pm

I have a 93 4.3l that is using alot of fuel
And seems to be boggy and lacking power.
And suggestions where to start looking
Would be greatly appreciated
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chasekerr23
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Re: 4.3 excessive fuel use

Postby chasekerr23 » Wed Feb 29, 2012 3:32 pm

Spark plugs, air filter, fuel filter?

Help us help you. Anything been replaced lately?
Once again, I have not posted because... I USED THE SEARCH FUNCTION!!!
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muskrat91
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Re: 4.3 excessive fuel use

Postby muskrat91 » Wed Feb 29, 2012 4:11 pm

if the engine is tuned up then one has to look at other things. How many miles are on the engine? Has the fuel filter/ air filter been changed recently? i know this one sounds dumb but these are getting old, so check for leaks around the tank & fuel lines. My 93 with 230k uses a lot more fuel than it should these days. The berarings are shot in mine I think so this summer she gets a fresh powerplant. :)
KyleS15
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Re: 4.3 excessive fuel use

Postby KyleS15 » Wed Feb 29, 2012 5:27 pm

I've done all the basics such as looking for leaks and regular service stuff.
Electrical diagnostics is my downfall in mechanics and I'm thinking the
Problem is an electrical sensor but how do I find out which one to go after
I was hoping this was a common sensor issue. Maybe EGR or something?
KyleS15
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Re: 4.3 excessive fuel use

Postby KyleS15 » Wed Feb 29, 2012 5:29 pm

I have also done a fuel pump recently cuz it stopped working
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sexxymike
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Re: 4.3 excessive fuel use

Postby sexxymike » Wed Feb 29, 2012 6:13 pm

Can't hurt to clean the egr. Do you have a check engine light on? Also a plugged catalytic converter will cause one to bogg and get worse fuel mileage. Dad had a car that went from getting 22ish to 28mpg with only the catalytic converter being removed.
Even a blind squirrel can get a nut every now and then.
KyleS15
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Re: 4.3 excessive fuel use

Postby KyleS15 » Fri Mar 02, 2012 1:41 pm

The truck Has already had the cat removed. And yes there is a check engine light on and when I scanned the truck it gave me a faulty O2 code but I replaced it and it's still the same. BUT I'm pretty sure the sensor is in the wrong place. It's after the Y pipe and I believe it's supposed to be in the manifold. Could anyone tell me a for sure location it should be?
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duxtoyz1988
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Re: 4.3 excessive fuel use

Postby duxtoyz1988 » Fri Mar 02, 2012 3:53 pm

my o2 sensor on my 88 with a 4.3 is in the pipe after the 'y'. thats where it came from the factory so urs is prob in the rite place too. u may have another one ur not finding......idk.
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sexxymike
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Re: 4.3 excessive fuel use

Postby sexxymike » Fri Mar 02, 2012 8:30 pm

Do you have a cpi or tbi engine? If you have the CPI there is a sensor on the side of the intake near the butterfly. It will have 2 star screws holding it in place. I was having a similar issue with my 93 pulled it cleaned it with brake parts cleaner and reinstalled with LOTS better running and idle.(let it dry before reinstalling) It has a mushroom looking tip on it with a spring behind it going into the elctronic sensor.
Even a blind squirrel can get a nut every now and then.
blazerman93
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Re: 4.3 excessive fuel use

Postby blazerman93 » Sun Mar 04, 2012 10:36 pm

what do you mean side of the intake near the butterfly?
93 s10 blazer 4dr torsion crank and shackles in rear sitting on 30 9.50 15s
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sexxymike
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Re: 4.3 excessive fuel use

Postby sexxymike » Mon Mar 05, 2012 7:40 am

Where the plastic intake tube goes into the aluminium intake, the sensor was on the driver side of the intake. Also if you have a tbi you may not have the same senser or it may be in a different location so disreguard what I have stated.
Even a blind squirrel can get a nut every now and then.
KyleS15
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Re: 4.3 excessive fuel use

Postby KyleS15 » Wed Mar 07, 2012 2:21 pm

Okay so here's the latest. The motor is a tbi 4.3. I relocated the o2(put it right after the y pipe and a bit deeper in the pipe and it now works. I got my power back but it's still running rich. I can smell gas out the tail pipe and the engine is giving me a code 45 (rich fuel) Any idea how to fix the problem? Injectors are working good and intake is clean. EGR is clean as well
blazerman93
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Re: 4.3 excessive fuel use

Postby blazerman93 » Wed Mar 07, 2012 10:33 pm

what temp is it running? and does it say anything else like o2 running rich?
93 s10 blazer 4dr torsion crank and shackles in rear sitting on 30 9.50 15s
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67Truckin
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Re: 4.3 excessive fuel use

Postby 67Truckin » Thu Mar 08, 2012 9:10 am

Are you positive the thermostat is working properly and if it is, then you may have a bad temp sensor which lets the computer know when the engine is up to operating temperature. Otherwise the comp will give it too much fuel similiar to a choke stuck on a carburetor. Depending on the year it may be called an Inlet Air Temp sensor.
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KyleS15
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Re: 4.3 excessive fuel use

Postby KyleS15 » Thu Mar 08, 2012 10:08 pm

The truck is running at 85C and all the scanner says is code 45 rich exhaust

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