I need help with my truck please. I have a 87 f150 302 fi manual trans. The problem is (I think) its flooding. Truck will start only if you floor it and will not turn over 1500 rpms. I have changed the fuel pressure regulator,fuel filter, plugs, distrebuter cap and rotor button. I think it is somthing electrical but not sure. Problem started when driving at highway speed the truck seemed to turn off (stall). When I tried to restart the engine It acted like the battery was dead. Altenator tested good.

 

Was '87 still carbureted, or was that the first EFI year?

 

it has efi

 

When you have it floored to start it, does it puff black smoke, or any smoke for that matter? Once it is running, do you have to stay on the gas to keep it going? Does it puff smoke if you keep it running? Is there a normal amount of exhaust?

 

when you get it running...is it missing? missing usually means spark issue

Try this

when you get it running and then it dies and it will not restart......pull a plug wire and check for spark....rule that out...

then concentrate on fuel system......pull an injector and check for fuel (turn ignition on and off a few times and watch for spray).....be carefull....I think the injectors that year are plastic and can be fragile...I cant remember..

try and narrow down to the affected system and go from there...

 

all plugs fire and the injectors are working. no smoke except when you first start usually back fire. yes have to keep it to the floor to keep running. and thanks for all the quick replys haven't been on the computer in a few days getting ready to move.

 

Do you have access to a timing light? It wouldn't hurt to check your timing to make sure you are getting the spark at the correct time. Some of the symptoms you are describing are similar to those when the timing is off.

Another thing to try may be to disconnect your exhaust before the catalytic convertor. A clogged cat/exhaust can cause the vehicle to stall going down the highway as you mentioned.

 

timing is fine just checked will disconnect exhaust today.

 

disconnected exhaust infront of collector still only runs when its floored. also replaced throttle position sensor becouse it through that code. now only code it through says system con't run idle speed. duh!

 

Try cleaning the IAC to see if the code will clear. It may also start w/out flooring it then.