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White smoke and liquid from exhaust 2003 Astro,

539 Views 11 Replies 8 Participants Last post by  CopperFiremist
2003 Astro not running well and smells and smokes while running after running out of gas. Cleaned MAF sensor and that helped with rough idle but still smokes.
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What color is the smoke? Probably sucked a little garbage into the pump and sent it to the filter. We clean throttle bodies as part of regular maintenance along with oil and air filter changes. Astro vans seldom actually need throttle bodies cleaned as the fuel is injected after that point, but it never hurts. If the fuel supply is the problem, use a diagnostic scanner, check engine data and look for fuel trim. If it is lean and starving for fuel, you will see trim data way up in the plus side, increasing fuel injector pulse width in attempt to compensate for fuel starvation. If you do not have access to the tools, the lean condition will also cause the exhaust to smell differently. Not saying you should sniff the exhaust, but you get the idea.

Check fuel pressure and if low, replace the fuel filter first. If pressure is still not adequate, it probably sucked enough stuff into the pump filter sock to affect fuel entering the pump. Either way, if you do have to remove the tank, replace the pump along with a new sock, most new pumps come with the sock, but with some you have to purchase it separately.

If you have the tank out, look down inside with the pump assembly removed and look for junk floating around in there. We have also had fuel level run low enough to where it will actually pick up small amounts of water and rust (even though it's a plastic tank) sloshing around inside. You might try some dry gas first, then check fuel pressure and if low, replace filter and then the pump. Use only brand name fuel additives and NOT cheap dollar store dry gas as we have learned whatever alcohol they use in some is too strong and can destroy fuel injectors. Have had it happen several times.

That being said, not quite sure as to what would be causing the smoke. Never seen that happen from running out of gas, but hey anything today is possible.
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Well, you didn't blow a head gasket from running out of gas, that's a certainty.

Yes, the pump is sitting in the bottom of the tank, obviously. The point being that when the tank has fuel in it, motion of the vehicle and resulting motion of the fuel in the tank helps to clean off rust and debris from the sock filter. As the tank nears empty and when finally empty, you no longer have that help and all the garbage gets stuck in the sock. If it has the chance to dry there when you are out of gas, even when you fill the tank again it does not always clean that crap off.

As for the smoke, check if you are losing coolant first. Before condemning a head gasket, check the dreaded heater flow control assembly. My current 2002 project had the seal in that valve leak and send small amounts of coolant into the intake resulting in white smoke from exhaust. Pain in the *** to get to and replace, but still easier then an unnecessary head gasket replacement.
It is a vacuum operated valve and there is a diaphragm/seal inside the valve head assembly that had a pinhole leak in it, causing coolant to be sucked through the vacuum line into the intake.
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