Randomly engine stalls while driving?

When starting the truck cold it will run at a slightly high idle approx 1300-1400 rpm then will go down to 1000 rpm after a few seconds. Without touching the throttle it will run smoothly for approximately 3-4 minutes then die. It will restart but not stay running unless I feather the throttle. It will not rev over 2500 rpm's no matter how I feather the throttle. I have completed a full tune up (plugs, cap, rotor, fuel filter, and wires) verified (twice) firing order 13726548. Fuel pressure test KOEO of 35psi and running 40psi, fuel pressure does not cut out when engine dies. Verified timing at 10 deg. TPS was tested (prior issue was that it would run for the 3-4 min then when the throttle was pressed the engine would die and not restart until engine was cold), TPS failed test and replaced. Still same results. IAC tested (failed by ohm test) replaced, same results. Checked for vacuum leaks by spraying ye old carb cleaner no change in RPM"s. Tried spraying carb cleaner down throttle body to see if RPM's would go higher, no change. Only DTC is 126, according to my source is that MAP sensor is higher or lower than expected. The only showing I have to test the MAP sensor is with a mulitmeter with hertz, the one item on my multimeter I do not have. I really detest "throwing parts" at a vehicle and want to make sure if there is another way to test the MAP. Or is there possibly something else a problem? Thank you so very much for what you guys do!

Checked the fuel pump it was bad thanks for your help.

Will start and run smoothly, or not start at all, or start then will stall out while driving. Have checked EGR valve, replaced fuel pump on front tank, and replaced Idle Air Control Valve. Any suggestions?

If your truck has a 4.9L and it stalls just as it goes out of start mode it is probably the crank sensor which is located down by the harmonic balancer. Behind the balancer there should be kind of a star shaped piece of metal, and to the right and side of this near the timing marks you should find a sensor that points at that star wheel behind the balancer. It kind of point at the wheel at a 45 degree angle and has a wire(s) coming out the end of it.

Hi, My truck makes a sound like it wants to stall but then its okay. I drive a bit longer then it just stops running do you know why? Any ideas on what that could be?

Thanks for the guides they helped me find out the fuel pump was bad, I got a new one and more more issues, thank you.

Hello, I was told by a mechanic (who did a tune-up, ck'd fuel filter, and replaced 1 plug wire), that my catalytic converter was bad. So, have been reading and asking? About taking them off or reaming them out. Well, I could reach to ream the rear cat, but all that did was plug up the front one. It ran great after I did that for about a mo, then one day it died again, just like before. Sooo since I can't afford to replace cats, and our state doesn't require them, I saws-alled the pipe just where the dual exhaust pipes enter the 1st cat, thinking I could ream out the 1st cat, then have the whole thing welded back together. Now, I'm worried about the effect doing this will have w/the oxygens sensors, and that they're bad, too. Have been too afraid to delve there yet! Ive totally cleaned out the rear cat, but wonder if I should leave the front one intact.
Also, bought a fuel filter because it sounds like it's not getting gas to even crank. Previously another mechanic said the fuel pump in the rear tank was shot, so he took off the locking gas cap for me, and I've been using that tank. Now I'm thinking that fuel pump is gone too. If so I'm w/o a vehicle at all! I've been living on UI for a couple years so cant afford to have anyone else ck. It for me, so any help would be most appreciated. Thank you, Donna

This problem only happens in 90 degree weather or hotter. After driving the truck for several hours in hot weather the engine starts to sputter than shuts off. Wont start for several hours until engine is totally cooled down.

When trying to start engine every ten to fifteen minutes while stranded, the engine cranks well but will not start. Eventually it finally fires but only for a second or two then shuts off. Let it cool down a little longer and it will start but sputters and backfires and then shuts off. Eventually I can get it to run poorly enough to get to where i'm going but it was sputtering the whole way and will shuts off if it drops below a certain rpm's or I come to a complete stop. I have to continue pumping the accelerator the whole time.

The next day it start immediately as if nothing ever happened. This problem only happens on a hot summer day. Never happens in the winter months.

It stalls when driving. Restarts immediately while rolling in neutral?

Thank you. It was the fuel pump this site rocks :)