Hello I'm new to this forum and I have a problem. My 95 f150 4.9l ran fine and then after sitting for about 2 weeks it would not start. It's got spark so I sprayed some gas down the intake and it would try to run. both fuel pumps make pressure. then after hooking up the pressure gauge it starts out of nowhere but runs pig rich. It cleans up at higher rpm's but stalls when you let off the throttle. The cel stays on the whole time but the code reading diagram I used from this site didn't work. Thanks.

 

Welcome to the forum! Why can't you read the codes? Try to disconnect a battery for 5 minutes to reset ECU and try to repeat reading codes.

 

There are no stupid questions, yeah right, here's one. After spraying the intake did you put the intake hose on? Needs to be inplace for everything to work properly. I'm not trying to be a wise guy.

 

I don't know if it matters as much with speed density but yes. Weird thing is when it wouldn't run at all the plugs were clean as a whistle like the injectors were not working. then after it starts they are heavily carboned up.

 

Recheck your connections and be very certain they are making contact. You may not have them inserted deep enough. You need to be absolutely sure the computer won't go into diagnostic mode because if it won't, the computer is fried or you have a broken wire.

 

well along those lines the fuel pumps come on and stay on. prior to starting the truck.

 

That's a good sign that the computer is bad, if they stay on without starting the truck.

 

was it this year that had issues with the harness connection at the ecm becoming water logged?

 

Keep trying to get the codes, but don't forget the basics. I would start by looking for a vacuum leak at all the hoses that are supplied vacuum. Then check for the leak at the intake manifold gasket. Spraying some starter fluid on the hoses and around the intake gasket is one way to find the leak. You will notice and obvious change in engine rpm if the fluid enters the intake track through a vacuum leak.

 

Perhaps the computer is compensating for the vacuum leak induced lean condition by over-richening the mixture. Look for that leak.