hi there,

i have a 91 e150, which is giving me some troubles. its a 302 with the same efi setup my 91 f-150 had.

cold, it runs up well. drives good.
getting warmer, it doesnt like when i try to drive away from idle.
it weakens and stutters, then it starts reacting and drives away.
sometimes, it even dies when i change gears, like from d to r.

i have changed ignition, sparks and cables. new air filter, new oil, new fuel pump.
it does also not seem to have any vacuum leakage, i did some testing with brake cleaner.

it feels like there are one or two cylinders missing, the warmer, the more.
also high speed driving is troublesome (>55mph), it bogs and stutters and automatic shifts back often to keep it going at higher speed (i do have to put down the gas pedal quite).

i realized that water temp is very low, it does not seem to heat up (i will replace the themostat, maybe its missing, next thing on the list)

has anybody some ideas? i am not experienced with ford efis...

thanks, chris.

 

If the coolant isn't warming up, you've probably got a stuck thermostat. Make sure to get the 190 or 195 degree one (stock value).

Have you checked for codes yet? That could give you some ideas where to start with the other symptoms.

 

just found out on fordfuelinjections.com how to do that.
gonna try that tomorrow.

 

if your truck is not warming up to normal operating temp, the computer will stay in closed loop and it will run like do-do. i would definitly tackle the thermostat first, there cheap

 

Agree with the thermostat thing - getting the engine to read normal operating temps. If that doesn't solve the problem, suggest to go through the EGR system - it doesn't become active until the engine is warm.

 

Ill wait on codes...

 

after the thermstate check your fuel filter if it stuters when takingoff it sounds like it isn't getting its fuel that would also explain at a higher speed it stutters

 

so.
did try to run a self test but i think i didnt make it.
got 11 11 13 131

whatever, i changed thermostat, now temps right.
but now idle drops even more, dies more often when changing gears.

found one leaking vac hose but didnt change anything.

checking ignition via pulling off cables i found out it doesnt react on 8th.
sparks there, compression also, but the injector does not seem to work.
signals there.
when i put 12v directly (manually) on the injector the engine reacts (like being flooded), but it doesnt when i put back the wiring.

so do i have a injector problem?
is that common on those engines?
would a new set of injectors be wise?

 

you can get 19lb injectors anywhere, ebay has a ton of them, everyone lists the ones they swap out in there mustangs (same exact kind)

 

the thing with you putting 12v to the injector doesn't make any sense because 12v's don't make the injector fire, switching the ground does.