I have a 87 f150 W/4.9 that has a stalling problem. Hot or cold it stalls when it goes into gear(auto). When I go to restart it won't unless I floor the throttle pedal. Then it sputters and is flooded till I rev it enough to clear it out. I can two-foot it & get it to go but has some hesitation. Even cold I can start it ,shut it off & it acts like it's flooded when I try to restart it. Any ideas? Thanks in advance.

 

Age/mileage of the plugs/wires/cap/rotor and filters?

Check Engine Light on?

Regardless of the CEL status have you checked for codes?

What have you already replaced to resolve the issue?

How long has this problem been happening?

 

Sorry not to have given more details, new at this. Plugs,wires,etc. 3months old, has been doing this a couple of mos.,getting worse. So far have checked for vacuum leaks,corrected a couple,blocked off vac. lines to brake booster and cruise to eliminate those as culprits. BTW I have had 2 modulator valves go bad in the last 6 mos and start sucking fluid from trans. I don't know if this has a bearing on problem or not.strange to have two new ones go out like that. Sort of think maybe fuel regulator valve or sticking injector. I know how to check pressure reg. but not how to check each inj. to see if one is sticking open to let fuel pressure bleed off causing a flooding issue. Thanks again for help.

 

Thanks for the details. That still leaves the question about codes. It's worth a check to see if the PCM thinks there is a problem.

Rent a fuel pressure gauge to see what the pressure is at the rail with the key cycled on/off a few times. It should be in the 50-60 PSI range on a 4.9L engine. It should hold pressure for several minutes or longer IIRC.

Then start the truck, check the pressure again. With the truck running remove the vacuum hose from the fuel pressure regulator, the pressure should increase to maximum (55-60 PSI range).