There is a way to check your pressure for leakage at rail vs at the pump. You need to find the lines for pressure and return and clamp them off once you reach pressure and monitor your fuel pressure gauge. If it bleeds off you have an injector leaking or o-ring, If not you probably have a fuel pump not holding pressure they should hold pressure. Could be fuel line, but if it were leaking you should smell raw fuel.

 

This may sound dumb, but how old is the gas inside the tank? If you've been driving it and have several fill-ups this is no issue, but if it's the same gas that was in it when you bought it in October, you may want to consider burning it out.

I've heard of coolant temp sensors going bad, but I think the problem would be opposite of what you have...that is, it would start okay, but stumble once it warmed up. This is due to the EEC thinking that theengine is still cold when it's actually warm...kind of like a stuck-on choke. Do you have a CEL on?

Another thought from way out in left field...this thought came from another thread wheelsup and I have contributed to. Find your fuel pump relay. There should be another relay in the power distribution box just like it (same part number)...perhaps for the power windows or something. Swap them out and see what happens. It's a long shot, but maybe the relay is hanging up in cold temps.

 

Thanks for the reply. Yeah the gas is new. I may have to check the relay also. oh, there isnt a cel.
today it was 34 degrees out and the truck fired instantly likeit usally dose when it is warmer.
Some one said it could be the upper intake gasket shrinking when cold, but I dont think that it is my problem because once it starts it only hesitates for a second at the most then is fine. I would think if it wwas leaking it would idle rough at least for a minute untile the gasket heated up and expanded. If it was the fuel pump wouldnt it have other drivsbility problems besides hard cold starts?
thanks

 

if there was a problem with it loosing pressure why dose it only affect it when it is below 30 degrees and not at 30 or higher? Could it be the ect sensor? I dont know much about his stuff. thank

 

In my older model EEC info, it says that during cranking, the EEC uses only the ECT sensor to determine the pulse width of the injectors. The timing becomes fixed at base timing, and other paramaters go to a default setting, basically presets and not computer controlled. I would guess it will be the same for your newer model. You may be on to something there...

 

I'm inclined to say also that rubber O-ring type seals will not seal as well when they are cold, as when they are warmer. BTW you have or rings in fuel line quick connects, fuel injectors, fuel pump connections. Just my two cents for the day.

 

I was just reading some info I had on 1st generation Ford stuff, and I think some, if not all, will apply to you. The book was published in 1992. It gives troubleshooting tips by symptom, of which one was "Delayed or Extended Start..." The probable cause list shows:
Improper drivers procedure
Sticking or binding TP sensor sending a high voltage to the EEC
High resistance in the Coolant Temp Sensor circuit
Incorrect Fuel Pressure
Stuck open EGR valve
Deteriorated secondary ignition (wires, plugs etc)
Drainage of fuel in the fuel rail back into the tank through the pump check valve or through the pressure regulator
Leaking injectors
The book then gives a brief paragraph for each probable cause. Under Coolant Temp Sensor, it says that if the problem is primarily cold start, use an ohmmeter to measure resistance of the sensor with the engine cold. I don't know if I can transpose the chart here, but I'll try:
50 degrees fahrenheit or less...58,750 ohms
68 degrees....37,300
86...24,270
104...16,150
122...10,970
and so on.
If you've already replaced the ECT sensor, I think you ought to really pursue the fuel pressure bleeding off issue if your problem remains.

 

I have a 96 Ranger 4.0 and I have the same problem. My truck needs new valve cover gaskets and intake gasket and I changed plugs and wires about 8 months ago. She also seems to "puff " out of the exhaust and run kinda crappy. Any Ideas?????

 

Again...my stuff is older and I'm not sure my knowledge is up to par with the OBD-II systems. Do you have a check engine light on? If not, the first place I'd go is to do a pressure test of the fuel system. Too low of pressurecould mean you didn't quite go far enough with your tune-up and have a clogged fuel filter. Too much pressure and you might have clogged injectors. With both conditions you could also have a faulty fuel pressure regulator. I've also seen posts that say stuck open thermostats could cause this. I'm sure wheelsup can give you some good advice here, but you might get more responses by starting a new thread and state as many details as you possibly can. Hope this helps.

 

Well, I replaced the iat and the ect sensors and that didnt help the cold start prob, cycling the pump four times dosent help. I heard that a bad maf could cause hard starts, I have tried cleaniing it. When I UNPLUG the maf the engine hesitated for a instant and ran just like before I unplugged it. It should mak a diffeence shouldnt it? The cel isnt on. I heard the computer could be in limp mode.