I am at my wits end, with my '87 F250 7.3. I put new injectors in and new GP's in, and it still won't start. It been plugged in, I can feel heat coming from the engine, so I know its warm. It turns over great but no fire. I went through the test in Haynes diesel manual for the GP system and everything check ed out.

Can you guys please tell me were I might be going wrong, some things to check, anything would be helpful.

 

Does it get diesel??
Have you checked the fuel solenoid on the IP?? Does it "click" when you put 12 volts on??

 

Thats what I am wondering, i will check that and let you know. thanks

 

Have you cheked that diesel comes all the way to the injectors..
How long does the GP stay on before it start to cycle??
If diesel dont make it to the injectors then i would check :::
Fuel filter
Feed pump
And last IP

Did you change the return line plastic tees??
When new with new o-rings they are litle difficult to get right on without damaging the o-rings.. Air leak into fuel line???

Try loosen the injector fuel lines and crank the engine.. Diesel should come visible on the top of injectors.

 

It clicks when I turned the key to on so that ok.

Anything else?

 

make sure its the FRONT one that clicks when you turn the key on inside the cab, just pull the back wire off and see if it clicks when you turn the key. sometimes they get mixed up and it wont start. next, is it a standard??? robably not, if it is tho, just ull it about 20 mph in 3rd gear for a while, and it should prime itself and take off. make sure both tanks have at least 1/2 tank in them, if the guage dont work, just fill em both up. then make sure the fuel filter is new and make sure to fill it all the way up with diesel, if you can, get a baldwin bf1222, they work great. next you should see a little shrader valve on top of the fuel filter, stick a nail or something in there and crank it over, it should spit out pretty good, at least to the middle of the motor and let it spit till all the air runs out of the system. then loosen all your injector lines and crank the motor till you see it spitting evenly out of all the injector lines. then it should start, if it is getting fuel, but still no start, get a rag and soak it with gasoline and take the air cleaner bowl off and hold that rag over the manifold, she should start then. she should start at least for a little while wether its getting fuel or not, just run on gas. then it should take off, you may have to re-soak the rag a couple times. go through all the steps and see which one doesn't work for you. then come back and we'll tell you what to do from there

 

Don't crank her too long, the starter burns up pretty easy in these things. An electric fuel pump is a real life/battery/starter saver if you can swing it.

 

I think I might have messed up on the wiring for the GP relay. Does any one know were to get a wiring diagram off the internet or you you have any idea where they might go.

 

those wires are a pain!! i remember something about a blue wire, that was real easy to forget to hook up, it has a funny looking connector, and that wire unplugged would make the light come on, but the glowlugs would be dead. just give her about 1/2 a second long shot of ether and see what she does. just a pst-pst. and she just might fire off like a brand new one, if this happens, then the glowlugs are not cycling. make sure that the battery volt guage gets sucked down to about 8 or 9 volts when the g.p.'s are on. and sometimes the light don't mean squat, because it won't match up with the actual glow plug on-time. like my light will come on for about 4 seconds, but the glowplugs will cycle a full 8 seconds. if yuo try to start it when the glowlugs are still on, the batteries will not have enough juice to run the starter fast enough to start the truck and run the glowplugs at the same time. i know this sounds like real bad news, but you may have burned the controller up alredy. i know i hooked a wire up wrong on the first one i bought for my truck and smoked it right there. try this. get in there, and where the white wire is hooked up, take that one off and run a ground from the motor, and then take the other small wire off and run it to a switch from in the cab. preferrably a pushbutton, or when mine was acting up, i just unplugged the horn and plugged my glowlug wire into the horn. whatever you want to do, but don't have the glowlugs on longer than 10 seconds, 12 seconds will burn every one of them up.then they will get stuck in the hole and you cant get em out. did you ever figure out if your gettin fuel to the injectors??? crack the lines loose?

 

turn the radio off and then turn the key on and listen real carefull while watching the battery guage it should be sittin at about 8 or 9 for about 8 seconds, then after 8 secondes it should click about 20 times real fast, if this is happening, then the glowplugs are working fine

 

The plugs are brand new, so I'm sure those are good. There is a green wire coming from the control unit and it goes to the relay, I think, do you know were that goes.

 

the green one goes to the big post hooked to the control unit , on the bottom part of the wavy thing. does that wavy thing get hot when the glowplugs are on?

 

Not sure, haven't touched it. should it get hot.

Well then I know that ones in the wrong spott can you tell me where the other ones are supposed to go. Thanks

 

the wavy should get hot enough to burn you bad.
the 2 big yellow wires from the truck should be on the big ost on top of solonoid.
2 big black wires are on bottom of the wavy thing.
a red from the controller should be on a small post, and the red from the truck should be on the same small post.
white should go to the other small post.
blue is the funny connector that plugs into the truck.
black goes to the engine ground
green goes on bottom big post, bottom part of the wavy thing with the 2 big black wires
yellow goes on top of the solonoid on the same post as the wavy thing

 

what does in mean if the wavy thing doesn't get hot?