Hey Tom==This is to general to even guess. What kind of car and engine do you have an does it do it when it is cold, hot or when???? GoodluckJoe
Some things that can cause it are bad plugs, to low idle, vacuum leak -check lines and regulator, worn out carbs not operating causing bad air fuel mix under a load, if automatic transmission under load some times gear locking up can happen. I have a 64 Corvair and after replacing all the vacuum system, plugs, filters fuel lines and changing the idle it still died, we then opened up the carbs and saw that they where worn out. After we got new carbs the problem was fixed. Note that if jerks forward and dies it could be the tranny but if you can hold on the brake and give it gas and it stays running but no power, then its most likely a carb problem witch could be vacuum or filter related too.
A problem in the fuel line could cause it to stall. On a stick shift, letting off the clutch too soon would cause the vehicle to stall.
Need to know the year and what it is in.
You need a tune-up
bad transfer case
vehicle is still in gear, step on clutch
Im not sure if its happend yet, But this was happening to mine and about a week later the trany poped-and was locked in 2nd gear. I could still shift it but putting it in any gear other then second or neutral would cause the eng to stall out. Was odd cause even in neutral the car would move but it was burning the mess out of the clutch. Basically if yo know how go to a junkyard an get another one the tranny is toast.
overheating it would. Or if it was stick not being in the right gear trying to find the system causing it would help, if the air intake or filter was so clogged it couldn't suck air it could stall, and low fuel pressure could also make it stall rather slowly. Bad electrical connections could cause a quicker stall.
The vehicle would stall when put in gear would be the fuel pump. The fuel pump is very weak which would explain why in neutral the vehicle starts if it gear it would have to have more gas.
It could be that the torque convertor is locked and not slipping which it should do as the normal operation
The real problem is manually shifting from gear to gear with an automatic transmission. If you are referring to the automatic upshift, there may be a problem with the EGR system or vacuum system.
yes, if you are doing too few revs for the gear you are in then you will stall.
your torque converter has locked up.... it's like having a manual transmission with no clutch.