1990 5.7 TBI no injector pulse when cold??

[K&S Morton]

Been stuck for a while, im coming to the pros. My truck will not start when
cold. no injector pulse. i can plug the block heater in and it will warm it
and it will start. below freezing without the heat its no start. below -20
the block heater cant keep up and no start also.
i have replaced the dist including icm and pick up coil...rotor, coil and
cap are all good. plan to rebuild my tbi unit to see if its an issue with
the fuel pressure regulator perhaps bleeding fuel and causing air and
freezing in the unit. any thoughts would be appreciated.
K

[Ed Pawlowski]

Post by K&S Morton
Been stuck for a while, im coming to the pros. My truck will not start when
cold. no injector pulse. i can plug the block heater in and it will warm it
and it will start. below freezing without the heat its no start. below -20
the block heater cant keep up and no start also.
i have replaced the dist including icm and pick up coil...rotor, coil and
cap are all good. plan to rebuild my tbi unit to see if its an issue with
the fuel pressure regulator perhaps bleeding fuel and causing air and
freezing in the unit. any thoughts would be appreciated.
K

Simple fix is to move to a warmer climate. Don't laugh, at the price
of parts these days it may be cheaper too.

[Geoff Welsh]

Post by K&S Morton
Been stuck for a while, im coming to the pros. My truck will not start when
cold. no injector pulse. i can plug the block heater in and it will warm it
and it will start. below freezing without the heat its no start. below -20
the block heater cant keep up and no start also.
i have replaced the dist including icm and pick up coil...rotor, coil and
cap are all good. plan to rebuild my tbi unit to see if its an issue with
the fuel pressure regulator perhaps bleeding fuel and causing air and
freezing in the unit. any thoughts would be appreciated.
K

usually when we talk about injector pulse, we mean the ground signal
from the ECM driver for that injector. Is that you are talking about?
Cuz freezing fuel wouldn't change that.

If OTOH, you mean there is no fuel spraying, then you need to find out
whether you have injector pulse, and if you do, find out if you have
fuel pressure, and if you do, try just heating the TB with a hair drier
instead of the whole engine, to test your freezing theory.

GW

[repairman54]

Post by K&S Morton
Been stuck for a while, im coming to the pros. My truck will not start
when cold. no injector pulse. i can plug the block heater in and it will
warm it and it will start. below freezing without the heat its no start.
below -20 the block heater cant keep up and no start also.
i have replaced the dist including icm and pick up coil...rotor, coil and
cap are all good. plan to rebuild my tbi unit to see if its an issue with
the fuel pressure regulator perhaps bleeding fuel and causing air and
freezing in the unit. any thoughts would be appreciated.
K

Some TBI systems used a low oil pressure cut off to shut down engine in a
rollover. Switch could be bad. Not enough oil pressure with slow cold
cranking to trip switch to turn on fuel.