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Its back... S10 miss when hot

My 96 s10 2.2 is missing again when its hot. Did the same thing last year. truck has been running fine otherwise. Same as last year. When it gets over 90 degrees, if i drive it too long the temp goes up to about 210, then its starts to sputter and sometimes dies. After it cools off, it will run again for awhile. When the ambient cools down, all is fine again. I have already changed the fuel filter.

I am back to the same two suspects, fuel pressure and electrical. I am more inclined to think its fuel pressure. But i am still confused why a Fuel pump would any fail under these conditions and after a short cool down, run ok and run OK otherwise when its cooler out. I still have not figured out how to put a pressure gauge on the fuel rail under the hood.

Any suggestions on how to trouble shoot this?

Some suggested that ethanol gas (which i use) can cause problems.

Bob

Reply to
Bob Urz
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FirsIs your S-10 a bi-fuel model? With 4 or 5 fuel lines going to the fuel filter? Charles

Reply to
Charles Bendig

No its not a FFV vehicle, I am not using the E85 gas. Just the mix with

5% or so that's suppose to be compatible with any vehicle (gasohol). Any other time of the year its not a problem.
Reply to
Bob Urz

Reply to
David J and Lynne J Shepherd

I did get the codes scanned. P0171 too lean P 0141 bank 2 O2 (O2 after cat) P 0300 random misfire p1870 (trannie)

The trannie is getting a filter and fluid soon. It shifts fine.

With the p0171 , its says lean. So it sounds like a fuel problem. I think if its starving, then the p0300 random misfire would go along with it. Hypothetically, if a coil pack was failing or some other ignition electrical related i would not see these types of codes?

Back to the too lean. Could the fuel somehow be boiling? I thought this was not possible because the fuel is constantly recirculating back to the tank. Could it be boiling on the other side of the pressure regulator on the fuel rail? Could the pressure regulator somehow screw up when hot? If it is the fuel pump, why only when over 90 degrees?

I still have not found a shrader fitting to check the fuel pressure under the hood.

Just to recap, the water temp is NOT in the red. It just slightly over 210. It seems to run ok at 210 unless its much over 90 ambient outdoors. Of course, running on the hilly expressway with the AC on high makes it hotter faster

Bob

Reply to
BOB URZ

recirculating

Reply to
David J and Lynne J Shepherd

Makes a lot of sense to me.

Rule of thumb here. Electronic systems are far less heat resistant than mechanical sytems. However, in a fuel injected setup, most of the time the electric fuel pump is in tank, cooled by the fuel. Your highest temps that electronic systems encounter are underhood. I am guessing you have an ignition part that has become heat sensitive.

Ted

Reply to
Ted Mittelstaedt

Any circuit has it's magic temp. It's never cool here (Maui) but I saw a few 1997 Ford E350 that would do exactly what you describe and it was the fuel pump. Of course, that means nothing other than it's possible.

If there's no shrader valve on the rail, you need to tee in with a good gauge SET at the feed (pressure) side.

Another possiblity here is that a fuel line has somehow moved much too close to a heat source. (Or your knock sensor is possesed by demons!?) GW

Reply to
Geoff Welsh

Reply to
sdlomi2

My 2003 S-10 with a 2.2L runs at 190 to 195 degrees. I've never seen it go above 200 degrees. I had an old Mustang that someone had slipped a 210 degree thermostat into and in the summer it would actually boil the fuel in the carb and then vapor lock, sputter to a stop and refuse to restart until it cooled down. I think I would focus on why it's running 215. Thermostat, fan, hoses, radiator.

GJ

Reply to
George Jetson

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