Well im sick of my truck not starting when its raining out. The problem is when the truck has been sitting in the rain for a couple of hours it doesn't like to start. I have fuel pressure at the rail, I have spark, I have crank. BUT the fuel injectors are not firing. Now I have it narrowed down to either a GEM module, ECM, Ignition control module, a cam synchronizer or cam position sensor. I have already replaced the Mass air flow so thats not it. Now which one would cause the injectors not to fire and nothing else. Once the truck is started it runs like a champ but it depends how wet or humid it is. if its a little damp out the truck will crank n crank n crank and finaly start after a little but if its pouring out for like two hours no way in hell will it start till its dry. If anyone can throw me some input or ideas it would be appreciated.

 

Spark Plug wires lacking dielectric grease and shorting? just a really wild guess.

 

nope, brand new wires and plugs 5k ago and Im getting spark at the plugs.

 

Bump, need some input.....

 

I'd bet it is water leaking in on a component of the computer. There is no other reason rain would do that.

 

well i mean honestly, i don't like getting out in the rain either. can you blame it?

I've seen a few fords that leak around the passenger side fender well and causing the fuses to go haywire.

 

I pulled the ECM and its dry, its even coverd in dust, plugs are clean and all. I haven't looked at GEM module or the Ignition control module yet though. Im just confused as to why the injectors are the only thing being affected. I know its got fuel pressure at the rail cause I have a Fuel pressure gauge on it.

 

Well changed the Crank position sensor today. Talked to a Ford tech and he said the cranks sensor triggers the injectors so I guess I have to wait till next time it rains to see if it works or not.

 

The EEC microcomputer circuit processes the input signals and produces output control signals to the fuel injectors to regulate fuel discharged to the injectors. It also adjusts ignition spark timing to provide the best balance between driveability and economy, and controls the IAC valve to maintain the proper idle speed.

 

that's from chiltons. let me see if i can find anything more.

 

Crank sensor fires the spark plugs, cam sensor times the injectors.

Mist the coilpack with some water while it's running, in the dark. Look for arcing, erratic idle when the spray hits "somewhere". Look there.