88 B2 has starting when cold outside

[beckalb95]

Ok so I've never had a problem with my B2 darting until about 2 weeks ago we had a cold front come in and it was from mid 40's to 50's for the week and every morning during that week it didn't want to start like it was starving for fuel, because when I would first go to start it in the mornings it would run for a split second and then shutoff like a fuel problem. So after beating on the tank and the fuel pressure regulator (even though I could hear them both running, but the pressure regulator sounded louder than normal so I figured it was empty) it would eventually start. But once the cold went away I had no trouble starting it in the mornings, and then tonight it's been about low 50's it took about 10 minutes of me beating on everything for it start up. Just wondering what could be the problem to this, because I can hear both pumps running but I don't understand why it acts like it's not getting any fuel when it's cold.


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[RonD]

Not cold enough for water in the fuel to ice up..............

Does the engine cold start normally in warmer weather, i.e.:
Engine starts and RPMs go up to 1,500+ (IAC valve opening all the way)
Then drops to 1,000 rpms (IAC valve closes per engine temp)
Then idle drops every minute or two until engine is warm and idle is 750 rpms, (computer getting ECT sensor data and lowering RPM based on engine temp)

If this is not happening then ECT sensor may be disconnected or bad, never replace this sensor, it is too easy to test.
ECT sensor is the TWO wire sensor, looks similar to the ONE wire sender used for the dashboard temp gauge.
ECT sensor is the "choke" for a fuel injected engine, colder weather requires more choking to richen the mix.

If the ECT sensor is showing engine is partially warmed up when it is actually colder then fuel mix won't be rich enough to start or keep engine running.
I doubt the "beating on it" is doing anything, lol, repeated restarts warms engine up enough to start, and time for that warmth to spread(while you are beating on it ).
ECT sensor data:
http://oldfuelinjection.com/?p=28


There is of course the TFI spark that could be the issue, weaker spark shows up more in colder weather, richer fuel/air mix means stronger spark is needed.
And battery voltage, colder weather means battery has less power, that's just chemistry, so that means when cranking engine the voltage is lower going to the coil, so weakens the spark more, if it was marginal the richer mix might be drowning the spark until engine cylinder gets warmer.

 

[AgPete139]

Good info here. ---^