engine wont stay running in gear

the truck cranks and runs fine. When its in neutral just sitting it idles and runs perfectly soon as you put it in gear to drive it the motor will start sputtering and try to die out as u give it gas.

it has had the plug wires,fuel pump,fuel filter,igntion coil and thermostats replaced all new think thats all weve replaced. what could be necxt to solve this problem?

ive check all the fuses and they are all good. not wure what to check next.

Push in the clutch pedal.....the one on the far left.....just kiddin'.

Is it auto or stick? I've only seen this problem on autos. Does it rev up in neutral?

its sitck and it revs up fine.

Is the clutch and tranny operating properly (is it turning and not locked up?)?. The only reason I could see the engine dying when you have it in gear is if something is locked up in the driveline. There isn't anything connected to the driveline that would interfere with the motor getting fuel or fire. EXCEPT for the safety switch to keep the truck from cranking in gear (four wheel drives have an interupt switch to allow this to happen).

I dont think its anything in the driveline it only does it some days and it seems more electrical problem. I went out today and found one vaccumn hose unhooked and hooked it back up. And i would unplug the TPS sensor while running and the truck would idle a lil lower and sound a lil better but never tried to drive it with it unplugged.

heres what made me write this thread.

Me and a buddy replaced the thermostat and cranked the truck it fired right up and was idling smoothly and sounded fine and would rev fine. We decided to take a test drive well we got in and put it in gear and when i went to give it gas it started jerking and sputtering like the motor was trying to shut off and it would do that every time i pressed the gas. havent drove it since few days ago. But in park/ neutral it fires right up and runs fine. it will sometimes go into low idle and sound like its about to shut off. so it seems to be a problem with maybe fuel or electrical at the motor.

any ideas?

I am having the exact same problem. I have been running with my TPS disconnected. It runs awesome, but does waste more gas...lol