Lately I have been having some trouble starting my truck in the mornings. Sometimes I wonder if it will ever start. Once the truck gets started, it runs like a champ all day long. Lately, the temperature has dropped about 10 to 15 degrees in the mornings and I suspect the teperature bring the culprit. I have asked around, and I am hearing to change my air temp sensor or my water temp sensor. Not too much of a problem for me to chang, but I wanna make sur I replace the right one. What are thes two sensors and how could they create this problem?


92 F150
V8 302

 

up

anyone?

 

Does it start like it is running rich? (black smoke) when was the last tune up, whats the mileage. Does it start better if you hold the pedal to the floor?

Could be injectors leaking, Fuel pressure regulator, Fuel pumps, secondary ingnition etc etc etc

Please post more info

Regards
Gasman

 

No, it just cranks like it's not getting a sufficient spark. Then finally it takes off, but misses a little and the acts like nothing ever happened. It only does this in the cooler mornings. The later I wait, the better she starts. Truck has 167K miles on it and has been tuned up a littl over a year ago. The TPS sensor has been changed recently.

 

Try holding the pedal to the floor while cranking. Then leting off when it starts of course. I have to do this with my 92 F150 302 when its cold. I suspect its the air charge temp sensor but I have not got around to changing or checking it.
Regards
Gasman

 

Well, In my case it does, it does this no matter where the gas pedal is. I also suspect the air charge sensor, but I am not really to sure what this really does for the whole starting process. That is why I came to this forum, hopefully someone can enlighlen me as to how these sensors work or what they are really used for.

 

Anybody with more input or experience on this would be great. My 93 351w does the same thing sorta, cranks longer first thing in the morning, but if sits for 6 hours or less, it usually fires up pretty well. It doesn't run rich or anything when doing this, but after it starts, occasionally the idle moves around between 800 and 1400 after starting cold. I put in a TPS, and I put in a new fuel filter, it's been tuned up, from coil all the way to plugs, and i just tonight advanced the timing to 13 BTDC and use premium fuel to get rid of the ping. I'll see how it starts in the morning.

 

anyone else?

 

try letting the key stay on the "on" position a few seconds longer before cranking. Even 10-15 sec. just to try it. this will give the fuel system more time to build up pressure. the eng. will not start until correct fuel pressure is at the injectors. Your pressure regulator may be allowing too much bleed down overnight or the pump or pumps maybe weak, taking a bit longer to get pressure up. Do you have 2 tanks? if so does it do the same on both tanks? With that kind of mileage there could be a variaty of things, such as weak compression in the cylinders, too much slack in the timing chain and other things. as far as the air charge sensor goes, you very seldom here of these going out. but i've had mine off (at about 80k)and it was black with build up. I cleaned it with contact cleaner, but didn't notice any diff. More likely the temp. sensor. You can get a house brand i think for around $20.00, but still if any sensor goes out, then it should kick out a code. but sensors can be out of "calibration" some and not necessarily throw the lite. hope this helps some...

 

I have tried letting the key on for as much as 10 seconds or so, and I have hooked up a fuel pressure guage to watch in the morning. The second i turn the key on, i have just over 40PSI. The next thing I'm going to try is the CTS. We'll see, i'll keep everyone posted.

 

How about some information. What year truck and what engine?

 

 

Im having the exact same problem but w/88 E150 van w/302 efi. At first i suspected the ignition system and went ahead and changed the TFI module but that didnt help. After some more checking I realized that the spark plugs were dry, no fuel even though it had fuel in the fuel rails and good pressure. For some reason the injectors werent firing first thing in the morning but after cranking on and off for an hour or so it would fire up and run great like nothing was ever wrong. Could be lack of fuel pressure will have to get a guage and check it. Meanwhile have removed and tested the TPS. It tested OK with an ohmeter but im not sure that is an accurate test. Have reinstalled it and see what happens tomorrow.