Motor is not running hot but stall's after 20min

ever look at those old bad spark plugs
see tip s black and gap so wide my bill of my cap fit there, omg wrong.
or its flooding
when did this old truck run perfectly
never seen it.
last month, last year, last decade?
I can name 50 causes of stalls.
can the stall be avoided with fast right too, (zero tools test)
bad engine,bad spark and bad fueling are the macro causes.
leaking injectors
clogged injectors, or partly
FPR when bad and fuel pressure way way out of spec PSI, covered in the service manual this is and the injector balance tests. and leak down test
all shops know all this and know what tests to do.
gee 29year old engine is compression 150psi and up and near equal?
then spark checked, and spark tips clean. no oil, no carbon , no coolant on tips
and last fueling checks, got tool;s?

would try and bring the temp down by lower degree thermostat hi-volume water pump bigger radiator maybe even double check timing sounds like you might be boiling fuel and hydro locking it

hot or cold engine or both?





which engine, to work on one, you need to know what it is

and what EFI system it uses. or its all just a crap shoot.

no new distributor cap and rotor why skip the full tune up,. why?



first questions.

1: can you save the stall with a a fast right foot.

2: why change out pump etc, if fuel pressure is at spec, a $20 tool would have saved you 5 hours hard labor and bath in fuel? why?





Stalls 101.:



the engine can stall for over 50 reasons are you going to do all 50?

surely not. why not consider diagnosis.. as a path.

1: car stalls, right foot saves it. and can drive fast if i keep foot busy.

a: ISC stuck closed.

b: EGR valve stuck open (depends on which engine options)

c: low compression on one or more cylinders.

2: can\'t save it from stalling (right foot)

a: fuel pressure is low. (wires bad.)

b: lost spark, for any reasons.

c: lost 12vdc to the EFI system( killing spark and fueling)



stalls.

hot or cold or both

stalls, can save it or not, hot and cold

hot restarts are easy and it runs good hot,yes./no.



there is lots more to it, then just stalls. lots more.

Did they figure out if you are loosing fuel or spark when it fails to start up ? You would need to know which to proceed.

chek filters for fuel on frame and in tank

are yougetting any codes could be a number of things really weak battery,alternator,something in emmissions, clogged catalytic convertor.and o2 sensor gone bad

possible ignition coil pack breaking down when hot....cools off and works again. pull plug wire off plug and check for spark when in this no start condition.vehicle must have air, fuel and spark to run.

Possible partially plugged filter, but also check ign coil...it could be "breaking down" when it gets hot!!!
Was distributor a guess, or was there a problem there? When it stalls, is there spark? Does it re-start and run normally after that?

Nothing wrong with the regulator. That is how it is supposed to work, it sounds normal.
I guess you will have to get to the spider to see what is wrong. Fuel delivery to the pot seems normal. Could be something to do with injector circuit, IDK. Sorry can't help more.

This sounds like a bad (probably cracked) ignition coil.

First, the coil gets hot when operating, and this is normal.

If it is cracked, it gets hot to the point where its resistance gets so much higher that it cannot provide enough voltage for spark.

When it cools back down it starts working fine again.