Gas Milage issues

Jaxom · 10-11-2009, 04:44 PM

While I'm saving for another vehicle to use as my daily driver, so I can do a swap on my '88 S-10 4x4 2.8L 700r4 w/ 124,400 miles... I've a few issues with milage and still smelling gas in the cab.

Since purchasing, I've...

gapped and replaced plugs

replaced wires

replaced cap and rotor

replaced module in dizzy

replaced IAC

replaced fuel pump

replaced air filter

I have a gut feelling that part of my gas milage issues is related to my dying transmission. I avoid steep hills and bridges as much as possible because I'd have to have the gas pedal to the floor, just to hit 30mph!

Things I'm concidering on replacing in the near future...

02 sensor

Map sensor

Clean and/or replace egr valve

replace serpentine and/or tensionor as nessary

This coming week I'm already set to replace my oil sending unit while doing that I'm going to replace the gas vapor filter. Both are within this weeks budget.

Once I have these things done, recheck timming...

There are two other things I may try as well, wish to hold off on for a bit longer. That is...

Rebuilding the TBI. I haven't decided whether I'm going to use keep the current 2.8L tbi until I do engine swap or upgrade to a 4.3L tbi. Why rebuild the smaller one only to upgrade to the lager one later?

It's quite possible, concidering how badly this truck was maintained, that the cat is bad. I know from visually inspecting and seeing holes in the muffler system... the whole thing needs to be replaced. This will be done the same time I swap the trans out.

Is there anything I'm missing? I surely would like to get more then 9-10mpg's that I am now. And then there's that issue of actually smelling gas in the cab that concerns me. I've checked and rechecked...no leaks anywhere from tank to filter to tbi... Suggestions?

Thanks

Jax

93v6banger · 10-11-2009, 10:52 PM

02 sensor was the best maintenance i did to my truck when i first got it.

Revolt · 10-11-2009, 11:38 PM

After all those replacement items, I'd go simple and check compression.

Double check for leaks, leaking gas isn't visible long before it evaporates.

mr spree · 10-12-2009, 02:26 PM

yea 02 sensor for me too

palillo2006 · 10-18-2009, 12:24 AM

If your smelling gas in the cab, then it might just be a fuel leak. You should really check it when the tuck is on. When it is on, there is fuel pressure which would make it easier to detect the fuel leak. Also do a compression test, gas fumes can build up in your crankcase due to bad rings.

89Chubby · 10-20-2009, 12:31 PM

Have you checked for vacuum leaks already?

Pulled the EGR valve to inspect/clean it?

Checked your ignition timing?

10-11-2009, 04:44 PM	#1
Jaxom Registered User Age: 44 Join Date: Feb 2008 Posts: 191 Location: User is: OffLine	Gas Milage issues While I'm saving for another vehicle to use as my daily driver, so I can do a swap on my '88 S-10 4x4 2.8L 700r4 w/ 124,400 miles... I've a few issues with milage and still smelling gas in the cab. Since purchasing, I've... gapped and replaced plugs replaced wires replaced cap and rotor replaced module in dizzy replaced IAC replaced fuel pump replaced air filter I have a gut feelling that part of my gas milage issues is related to my dying transmission. I avoid steep hills and bridges as much as possible because I'd have to have the gas pedal to the floor, just to hit 30mph! Things I'm concidering on replacing in the near future... 02 sensor Map sensor Clean and/or replace egr valve replace serpentine and/or tensionor as nessary This coming week I'm already set to replace my oil sending unit while doing that I'm going to replace the gas vapor filter. Both are within this weeks budget. Once I have these things done, recheck timming... There are two other things I may try as well, wish to hold off on for a bit longer. That is... Rebuilding the TBI. I haven't decided whether I'm going to use keep the current 2.8L tbi until I do engine swap or upgrade to a 4.3L tbi. Why rebuild the smaller one only to upgrade to the lager one later? It's quite possible, concidering how badly this truck was maintained, that the cat is bad. I know from visually inspecting and seeing holes in the muffler system... the whole thing needs to be replaced. This will be done the same time I swap the trans out. Is there anything I'm missing? I surely would like to get more then 9-10mpg's that I am now. And then there's that issue of actually smelling gas in the cab that concerns me. I've checked and rechecked...no leaks anywhere from tank to filter to tbi... Suggestions? Thanks Jax
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10-11-2009, 10:52 PM	#2
93v6banger first car and proud Age: 16 Join Date: Jul 2008 Posts: 749 Location: Lebanon, IN User is: OffLine	Re: Gas Milage issues 02 sensor was the best maintenance i did to my truck when i first got it.
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10-11-2009, 11:38 PM	#3
Revolt Registered User Join Date: Oct 2009 Posts: 24 Location: User is: OffLine	Re: Gas Milage issues After all those replacement items, I'd go simple and check compression. Double check for leaks, leaking gas isn't visible long before it evaporates.
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10-12-2009, 02:26 PM	#4
mr spree Whats this for? Age: 20 Join Date: Jan 2008 Posts: 1,115 Location: Spokane WA User is: OffLine	Re: Gas Milage issues yea 02 sensor for me too
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10-18-2009, 12:24 AM	#5
palillo2006 Registered User Join Date: Nov 2008 Posts: 4 Location: User is: OffLine	Re: Gas Milage issues If your smelling gas in the cab, then it might just be a fuel leak. You should really check it when the tuck is on. When it is on, there is fuel pressure which would make it easier to detect the fuel leak. Also do a compression test, gas fumes can build up in your crankcase due to bad rings.
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10-20-2009, 12:31 PM	#6
89Chubby King Turd Polisher Join Date: Dec 2007 Posts: 492 Location: Apache Junction, AZ User is: OffLine	Re: Gas Milage issues Have you checked for vacuum leaks already? Pulled the EGR valve to inspect/clean it? Checked your ignition timing?
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