Hello> I really need some help as I am STUMPED... I have a 1995 ford f250 5 SPEED 2WD WITH THE 5.8 EFI. It has the Map sensor not mass air. My truck will turn over but not start. It is getting good fire to all of the plugs. It has new plugs wires cap, r-button, and pickup sensor. I have taken loose all of the grounds(ground near bat, front and ground by computer, ground on frame, block, firewall.) and grinded behind them and put them back on. the fuel pump is new in the rear tank and is getting 40 lbs at the rail when the engine is turning over. the pcm is new, as well as the module mounted on the driver fender. When key is on check engine light is working as it should and fuel pump primes for a few sec. new battery. sometimes also when you turn the switch nothing happens and then the next time it will work. it will run if i spray gas into the throttle body. I checked all fuses and relays and they are good. The injectors are getting positive on both wires and arent pulsing when its running. when key is on and when it turns over it sputters for a sec but never runs all the way. I am stumped. PLEASE HELP... It seems it is a grounding problem but I have checked and checked. Is there any grounds that I can run from batt to computer or anything to bypass the other ones or does any1 have any suggestions? thanks

 

I'd say pull the codes but if you had the battery disconnected recently there's not gonna be anything to pull. Is this truck new to you? Did this problem suddenly occur and leave you stranded? Has any work been done on the truck recently?

Your problem is related to communication(or lack of) between the ignition module and the computer. Has the module been replaced recently? On your truck it's fender mounted over near the brake booster, there are two different versions of these things a grey and a black module, and you must use the correct one for your truck. It's possible you have the wrong module on there now and because of that the computer isn't seeing the ignition stream that originates in the distributor. The fact you are getting spark means the distributor is functioning as it should so I wouldn't suspect it at this time. Also look for chewed or broken wires at the ignition module or computer connector connector.

 

thanks for the reply. I just replaced the module yesterday with the black one. same that came off of it. It sat for a few years and yes its new to me. I bought it from a buddy who did alot of the parts swapping trying to fix it. I do think he replaced the wiring harness with another used one from another truck. I do see where there is a plug unplugged on the back of the intake on drivers side. there looks like the other truck had 2 of these vacuum solenoids or whatever it is and this truck only has one. so the other is just unplugged. its in the injector harness. is there any grounds that i can straight wire or anything like that to try. or should I just try another harness? Im almost to the point of putting a carb and hei on it and being done with it haha.but it just seems like something so simple and there has been so much $ spent on fixing the efi i hate to waste it. could there be any thing in the ignition switch not making the injectors fire. because its like it tries to start then just dies and keeps turning over.

 

......................................

 

OK with that info I'm gonna suggest you pull the codes, if you get a big list that's a good indication the wiring harness is the problem, and that means you either need a wiring diagram and a multimeter to sort out what's wrong with the one you have or you need to swap in another from a truck of the same year and engine as yours. You could still have the wrong ignition module on the truck though, some parts stores list the wrong part for these truck putting a black module where a grey is needed, and that is something that's fairly easy to test so it may be worth a try.

 

ok thanks. what is a good source for the wiring diagram. showing what pin and wire color does what.

 

thanks for your help BTW!

 

You need to source a Ford service manual for that year truck if you want wire color codes, the Chiltons/Haynes manuals are more generic and probably won't match what you have. That said this site has a lot of good info.. Fuel Injection Technical Library
But before you go there at all pull the codes to see what comes up, if you don't get a big list then the harness is probably fine and you'll save yourself a ton of time looking for stuff you don't even need. If you get no codes or only one or two then we can help you track down where the problem is, but I'd also suggest you go find a grey ignition module to try on the truck.. even something used for a test, you'll know right away if the problem is fixed or not. BTW codes can be pulled without any special tools, put a jumper(paperclip) between the STI and Sig_Rtn wires in the EEC Test harness, turn the key to run and count the flashes on the check engine light. More info here.. Fuel Injection Technical Library » How To Run a Self-Test

 

ok i got codes 113 and 116. Thanks for the help