My 87 f150 w 5.0l fuel injection has a horrible cold start problem, coughs sputters and has a hard time till it warms up, then it is good as gold. New to Fords, anybody got any ideas? Just replaced injectors and hp fuel pump, plugs, wires, etc.

 

Clean the throttle body. Cheap place to start

 

it is so clean you could see yourself, went through it when I changed out injectors. Friends tell me it is just the nature of the beast, but I refuse to believe. Actually thought about Throttle Position Sensor, but that doesn't seem to be it either.

 

Check for codes and check for vacuum leaks. Test fuel pressure and check the timing, make sure to remove the spout connector. Check the function of the secondary air injection system. Check for wiring issues to the ecu, IAC, and TPS. Make sure the throttle and IAC isn't stuck and that no one messed with the idle screw. That ought to get you somewhere. It shouldn't have a problem starting up.

 

2-wire temp sensor is either roached or not connected....

its on or near the Thermostat housing.... that is also a Cold Start Sensor. if it is bad it most of the time tells the ECU the engine is warm when in fact it's not so it never enters Cold Enrichment stage.....

 

The ect and act determines how much fuel is used when you first turn the key. The iac is open 100% Spark control is taken over by the tfi as long as you hold the key. Timing is also determine by the ect and act at first start up. The pip steady`s out and the map and 02 sensor starts to help out. The o2 don`t kick in in tell it hits 600*. As the engine get to about 160* the eec uses the ect and the tps.

 

Ah forgot the ECT.

 

first thing I go to for a cold start issue.... GM, Dodge, Ford they all have them and they all do the same thing.

 

Did you ever get this fixed??