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1990 5.7 TBI no injector pulse when cold??

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

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

Reply to
Ed Pawlowski

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

Reply to
Geoff Welsh

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.

Reply to
repairman54

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