Long story-short, all was fine until yesterday, I went to start it up and it sounded like the fuel pump prime that you normally hear when you switch it on did not stop. It turn and turned but did not fire. I popped the hood to check things out and tried again. It started right up, but ran like it had water in the gas, very rough and would not run unless I held my foot on the gas. it finally leveled out and I left....all ran fine but I did notice that the temperature guage did move but never showed normal range. I went back this afternoon and everything worked like normal, I turned the key, it fired right up and leveled briefly and died.....started right back up but is running rough again, did not have time to let it run with my help to see if it leveled or not, but it smelled really strong exhaust wise and also the CEL is on.......

Does this sound like anything any of you have experienced? If so tell me about it and is there a "home" way to check the codes...??

1990 F150/302 4X4........Thanks.........DD

 

I've never personaly experinced this, but I have heard of the pump sticking and actually over loading the injector rail this would make it run rough and give you heavy exhaust emissions. If you have a frame rail pump start there and tap it a few times with a rubber hammer. I'm not exactly sure what pressure you need at the rail but I would decompress the injector rail valve and see if it seems excessive or ask around and find out the psi needed at the rail! Check it with a fuel pressure gauge. Auto Zone and Advanced do free scanning here in the south east not sure about your area, but I believe it would be the same every where. Check the timing as well if it jumped time due to a stretched chain that would make it run like that. Hope this helps!

 

The symptoms sound similar to ones I had recently. It could be many different things unfortunately, like a vacuum leak, bad plenum gasket, or excessive fuel pressure. My problem was the Fuel Pressure Regulator (FPR). My trucks symptoms were running incredibly rich, up and down idle, stalled when hot on transition from stop to moving, ran like water in the gas.

I have a '94 302 4x4, and with a little prodding at the dealer (after I fixed it of course) I found that the FPR was still considered a recall, and they are going to replace the aftermarket one I put in with a Motorcraft one.

If yours is like mine there is a schrader valve on the fuel rail on the driver side. If you have access to a pressure tester it's easy to check. Mine came in at 80psi. Should be around 35 PSI at idle, maybe up to 40 when punched, and I think not below 30. Mine now stays rock solid at 34. You can also pull the vacuum line at the FPR and sniff it...if there's a gas smell, it's definitely bad. No smell does not necessarily mean it's ok though.

I spent $60 on a fancy tester with bleed off valve and fittings for different vehicles. This only confirmed what I tested with my bicycle pump (that has a dial PSI gauge)...the pressure was running at 80psi. Point is, You can get a $10 tire gauge with a dial and check it...if you have excess pressure it's likely the FPR, although it coulds be the return line the FPR uses to dump excess fuel is plugged. (Not likely.)

Again: if it is the FPR, see if you can get the dealer to fix it!