Starting issues

[motoman]

I've got a 92 F150 XLT with the 4.9L 300 I6. I've had some issues with it starting recently where it doesn't want to start. I've been through the basics; starter, alternator, plugs, plug wires, battery, and those are confirmed good and working. I took it over to my mechanic to have him look at it in his spare time and he pulled the code for air intake temperature sensor. He pulls it out, cleans it up, puts it back in and it starts back up. Problem is it's not starting every time. He said it feels like the engine is flooded and not wanting to start because of it. The truck has always smelled like it ran rich from the first day I picked it up.

Does anyone have any insight or ideas as what to check next? Will replacing the IAT be any better than just cleaning it?

[scootro]

good luck! i had one of those trucks and had to get rid of that gas hog. i kept adding parts to it until i couldn't take it anymore.

[motoman]

Thanks man. The only reason I'm keeping it is because it's paid off and still runs strong for the most part.

[034V]

BPS (baro pressure sensor), ect, ait would be by starting points. then fuel pressure reg and rail pressure test when hot.

[Baron Von Crowder]

does it do it all the time, only when its hot, only cold, etc?

[motoman]

does it do it all the time, only when its hot, only cold, etc?

Last time it ran, the temp was roughly 45-50* outside. He tried yesterday and it still didn't want to start.

[SEB]

ignition, Something about this time of year with the cold weather & moisture in the air. It causes the older vehicles to have issues. On 2 different vehicles it was ignition related. My neighbor has a 2002 F150 6 cycl & he brought it over to me & drove it & felt like the truck was missing & wasnt running on all the cycl, replaced Plugs & wires & coil packs & runs good again.

[Baron Von Crowder]

might check TFI

[motoman]

ignition, Something about this time of year with the cold weather & moisture in the air. It causes the older vehicles to have issues. On 2 different vehicles it was ignition related. My neighbor has a 2002 F150 6 cycl & he brought it over to me & drove it & felt like the truck was missing & wasnt running on all the cycl, replaced Plugs & wires & coil packs & runs good again.

Everything ignition (plugs, wires, distributor, etc...) is confirmed good and working.

[mstng86]

What about the maf sensor? Cleaned it?

[motoman]

What about the maf sensor? Cleaned it?

92's don't have MAF.

[JC316]

Been there, done that. These trucks are very sensitive to the intake air temperature and engine coolant temperature sensor. If they go out, you will have hell starting the truck and it will run pig rich. Change both and it should be fine.

[motoman]

Still chasing the issue with my truck. It'll go 2, 3, 4 days and start just fine and out of no where it won't start.


Checked. IAT sensor
Map sensor
Coolant sensor
All 02 sensors
All are working

Tune Up: plugs, wires, cap, and rotor were replaced.

[SC457A]

Try and monitor fuel pressure when it does not start. I know you said it smells rich, but seen bad fuel pressure cause a lot of issues.

It seems you checked everything but fuel system.

[motoman]

We checked the fuel pumps to make sure they're working but I'm sure there's more that can be checked.