can't get 7.3 to start

[xpbprox]

If you don't want to read all of it just SKIP to the last 2 paragraphs

So I bought this 85 diesel a little while ago and I haven't been able to get it started. Story is that I bought it from a guy who bought it from a guy who was in the middle of swapping in a 7.3 from a 92. Got it wth the ip and injector lines just loosely placed on top of the black, everything else was hooked up but the ip and the injector lines. Well I had a hell of a time figuring out how to actually place the ip gear as everything was lose. I finally got the Y's lined up. hooked everything up truck didn't start. Didn't know what I was looking at so i blindly bought some used "working" injectors. After cracking one of my old ones and one of the working ones, I could clearly tell the difference that the injector's nozzle was actually rusted to the the nozzle housing. So my old ones were shot!

Installed new ones, tried to start again.....NOTHING. Now this time I learned that you're supposed to bleed the lines by cracking them open at the injector. I couldn't get and fuel to bleed out. (TURNS OUT THERE WASN'T ANY) but didn't find that out till later.

So blindly again I went and bought a used IP, installed it. Tried to start again, nothing. So this time I decided to completely disconnected one of the injector lines to see if fuel was even coming out. Didn't see any fuel, maybe a little drip here and there. So here's where I'm at. Lift pump has not been tested for pressure but when I install the IP completely dry, it gets filled up. I can tell because I removed the top cover and it full of fuel. I understand that the FSS had to be installed correctly which I believe I have been doing. My whole engine harness does not work so I got it rigged with some romex straight the the battery when I'm trying to start.

So I guess my question is could I have possibly just have had 2 bad IPs or what? I'm thinking I need to run some ATF through the new used one I just put on. I actually went to the junkyard to pick this one up and saw the guy remove it off of a complete 6.9 block. So maybe because it had a bad IP is how it got there in the 1st place or it's just sticky from the time it's been sitting. I took the fuel screw plate off and I could see the shaft rotate. Any ideas?

 

[LARRY RANALLO]

My whole engine harness does not work so I got it rigged with some romex straight the the battery... are you say that there's 12volts going to the fss...

 

[xpbprox]

Yeah I got it wired directly to the battery and I can hear the noticeable click. I've also test it with the just a grounded cover and I can see it activating.

 

[lindstromjd]

Soooo... do you have a way to activate your glow plugs?

 

[xpbprox]

Yes they PO put in a manual button. I tested it and the GPs are getting 12v, now do the GPs them self actually work, I don't know

 

[SparkandFire]

I would certainly test the glow plugs with a test light, one at a time with the lead wire clipped to the positive terminal on the battery.

I know that my brown truck would NOT even think of starting if I had one bad GP. I would try starting on just a "SNIFF" of starting fluid (don't use the GP pushbutton at all if doing this)



Also take the fuel filter off and see if there is fuel in there? Push in the schrader valve while cranking and see if fuel comes out.

A failed lift pump, or air leak will cause rough starting issues.

 

[xpbprox]

I haven't really gone too much into checking out my GPs, I do plan on replacing all of them with motocross ones but I'm thinking that I'm not even getting fuel in the first place. So that's kind of where my focus is then once I get that ill check the GP system. I had some one crank while I was pushing the schrader valve and fuel was coming out, I plan on putting a fuel pressure gauge in there so I can see how much psi I'm getting. The fuel filter is full. I agree the fuel pump needs to be checked for proper function.

 

[xpbprox]

I'm still at a loss with this truck, I think I need to stop being cheap and just fork out the money for a reman or buy a working pump off of someone here before I burn my bearings worse. I'm pretty sure lift pump works, besides I think you only need 1psi?

 

[460mudsports]

I recently bought a not running 88 International S1600 Uhaul truck with a 7.3 and a 5 speed manual. This truck had been sitting for 2+ years. I tried about everything I could think of to get it started. It also acted like it was not getting fuel. I was getting fuel at the injectors, at least I could crack the lines loose and get a little out at each injector. It would not even try to hit, even with a shot of ether. I finally decided the starter was not turning it over fast enough. I had a friend help me pull start it. It tried to start in less than 50 feet and then started, running roughly but running, in another 100 feet. We unhooked the chain and I drove it for a couple of miles and it is smoothing out, but still not quite smooth yet. It does still smoke and runs rough, but it has started easily since then.
I don't know if this might help you or not, but I thought I would pass along what I have experienced with mine. I probably cranked mine over for at least 30 minutes (15 to 45 seconds at time over 3 weeks) with no luck. If you have a manual transmission and somewhere you could pull it, you might give it a try. If you have an automatic and an extra starter you don't mind toasting, you might try hitting the starter with 24v instead of 12v to get it turning over faster. I have never tried this on a diesel, but it is an old demolition derby standard mod for gasburners around here.
Good luck!

 

[lindstromjd]

I'm still at a loss with this truck, I think I need to stop being cheap and just fork out the money for a reman or buy a working pump off of someone here before I burn my bearings worse. I'm pretty sure lift pump works, besides I think you only need 1psi?

You need 3-5 psi for fuel pressure. Are you 100% sure that the FSS switch is working? That's a problem I ran into once... nothing I did made a difference, until I figured out that the FSS wasn't clicking open. Open up your IP and check it just to make sure, and fill it completely full of fuel while it's open. The IP in question for me was also just caked in rust... it was gross.

 

[xpbprox]

Well the starter is the stock one I believe, I have a C6. I think Its spinning fast enough. Thanks, though I will keep that in the back of my mind

I know the FSS is working, I'm 90% sure I installed it right. Hell I even remember reading somewhere that you can take the cover off and manually move the lever and get it started that way. I just have one question though, if you're looking at the engine, if you push the shut off lever towards the back of the truck that means that it is being cut off and if you release it and let it go toward the front then that means fuel will flow. Correct?
Also the fuel pump fills up the IP by itself all the way.

 

[460mudsports]

The FSS is shut off by default with a spring. It opens (run) only with 12v applied. I had mine open yesterday, and yes I do belive you are correct that back is off and forward is run. If you install it incorrectly, your engine will not shut off with the key and could possibly have a high speed runaway. If you start an engine with it installed incorrectly, you must eliminate the fuel supply to let it run out of fuel to shut it off.

 

[hesutton]

My two cents would be to get a rebuilt injection pump and injectors if you can afford it. Used fuel parts are such a crap-shoot and often a losing bet. After reading about the gear being off the engine, make certain it is properly timed with the cam gear. If it is off a few teeth, it may never start. With good timing, good IP and injectors, good fuel supply, good cranking speed, functional glowplugs, and with all the air out of the system....... it should start.

I wish you were closer so I could have a look and see if I could help ya out. Unfortunately, this is all I can offer.

Good luck and keep us up to date on the progress.

Heath

 

[xpbprox]

Thanks 460 and hesutton.

Gettin the timing is kinda hard too with the front cover on, if I was even getting fuel and it didn't start then I would take the front cover off and get it aligned correct
I'm probably going to be looking into gettin a rebuilt one, I'm just hesitant on spending money on an engine that i don't even know if its good. I could always rebuild it though, it wouldn't be a problem but if it came down to rebuilding it I would probably just swap in a different engine.

 

[xpbprox]

Update
I just installed a different IP that I got from a member here who also happen to sell me the injectors that I'm running now. Hopefully when I can get another set of hands, I can prime this bad boy and bleed it