7.3 idi starting problem

[Cdl250]

I just put a 7.3 idi in my 86 f250 and used the injection pump off my 6.9 because i was told the injection pump was bad on the 7.3 i bought . I put a injector oring and return line kit on . Cracked all the injectors and got it to start after alot of cranking . So next day went to go start it and had to crank it for 2 minutes until it started. When warm it still takes a little to start . Compression tested all cylinders and had 450-500 in each. So i figured it was just losing fuel pressure , i went over everything on the fuel system and no leaks. The only thing is the steel return line has a crimp in it , not leaking . I just installed an electric fuel pump wired to a switch to help prime the system, that didnt seem to help. But if ths block heater is plugged in it starts up after 40 sec of cranking. No glow plugs used . I have a manual switch bypassed the controller. Any ideas what could be wrong ? After my electric fuel pump test , im starting to think its not the fuel system..

 

[mjs2011]

Verify that your injector return caps are seated. They pop down with a good firm push. My guess is one or more of the caps aren't seated and are allowing fuel to drain back through the IP.

 

[dunk]

But if ths block heater is plugged in it starts up after 40 sec of cranking. No glow plugs used . I have a manual switch bypassed the controller.

And does using the glow plugs make it start in less than 40 seconds? Mine does not kick off right away without glow plugs on a cold engine and I've never actually cranked enough to start it cold without running the plugs. Running glow plugs 7-10 seconds and it fires immediately, like by the second revolution. Batteries and cables good? You sure there's no air leaks on injector caps or return lines? Running electric pump a few seconds before cranking should help if that was the case. My pump is on the way out and on hot starts on very hot days every now and again it'll crank a long time before firing but if I pour some room temp water over the pump head it kicks off right away. Maybe I'm not understanding the problem. Does it start quickly when using glow plugs?

 

[Cdl250]

No it still starts hard with glow plugs . The way i started it before it got really cold out was crank it for 30 sec 4 times , then give it glow plugs for 10 sec then crank it and it would start at 30sec , or id give it glow plugs and crank it again. Like to me it seems like its sucking air and sending fuel back to the tank .. But i cant find it anywhere . And i dont think the timing is off that bad . Im stumped .. The fact that it starts so easily when plugged in confuses the hell out of me

 

[3Kp]

Have you tested the glow plugs, glow plug harness, or glow plug relay? When I first bought mine I only had 3 working glow plugs and a broken harness. Now it will start at 6 degree wind chills with out being plugged in.

 

[Cdl250]

Have you tested the glow plugs, glow plug harness, or glow plug relay? When I first bought mine I only had 3 working glow plugs and a broken harness. Now it will start at 6 degree wind chills with out being plugged in.

All new plugs hooked to a manual switch

 

[C_Luft]

Make sure your only using a electric fuel pump or a mechanical fuel pump, using both will cause the mechanical fuel pump to leak fuel into the crank case, and when you swapped the injection pumps did you remove the injection pump gear housing and reinstall it, because I have heard that these engines will start being 180° out of timing. You may need to time the injection pump using a ferret adapter. Also do you get any smoke when it takes 30+ seconds to start?

A good engine, with good timing, new return lines and glow plugs, should start within 3 sec of the glow plugs cycling, my old engine had 2 dead cylinders and would start within 2 seconds at 19°f.

 

[Can30Diesel]

I'd check the glow plugs again. I ended up going with self regulating ones because for some reason the stock ones were getting too much voltage and burning out after a couple uses even with the manual switch.

 

[Can30Diesel]

Here are mine after about 4 years of use as a daily driver..

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[Cdl250]

Make sure your only using a electric fuel pump or a mechanical fuel pump, using both will cause the mechanical fuel pump to leak fuel into the crank case, and when you swapped the injection pumps did you remove the injection pump gear housing and reinstall it, because I have heard that these engines will start being 180° out of timing. You may need to time the injection pump using a ferret adapter. Also do you get any smoke when it takes 30+ seconds to start?


A good engine, with good timing, new return lines and glow plugs, should start within 3 sec of the glow plugs cycling, my old engine had 2 dead cylinders and would start within 2 seconds at 19°f.

I was just using the electric to prime it then shutting it off . And it leaves a cloud when it starts , but it also burns oil like crazy so that has a part if the smoke.i took the injection pump off in one peice and my friend is the one who put it on and timed it . We tried advancing and retarding it and it didnt make a difference . But its possible for them to run 180 degrees out ?

 

[Cdl250]

Here are mine after about 4 years of use as a daily driver..

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What brand are they ?

 

[Can30Diesel]

I can't recall for sure, I bought them ages ago on Ebay. But I know they are dual coil self regulating ones from what I remember reading. I believe they are made by Wellman. According to the a site selling what looks and sounds like mine, E3TZ12A342A Motorcraft ZD1A is the FORD interchange part number.

 

[Can30Diesel]

I think this is the place I got them from.

http://www.ebay.ca/itm/Ford-83-88-6...Parts_Accessories&hash=item5644cc0d15&vxp=mtr

 

[C_Luft]

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this is the proper way to set timing when you have the injection pump and the housing as one unit.

The the glow plugs should clearly say beru if not, go out and buy a set of 8 beru/Motorcraft glow plugs, because other brands will swell and get stuck or break a glow plug tip off and then you will be pulling the heads,

Since there from accurate diesel, I (guess) there ok but I would rather spend 10-20 extra on beru/motorcraft than risk a head removal.

I also noticed that said that you burn a lot of oil, have you changed your cdr, it's the tuna can behind the intake.

 

[Kistthesky]

I just put a 7.3 idi in my 86 f250 and used the injection pump off my 6.9 because i was told the injection pump was bad on the 7.3 i bought .

Aren't the 6.9 & 7.3 IP's a little bit different? They have different part numbers & I read somewhere they work at slightly different fuel pressures, maybe need to use the 6.9 injectors if you are using the 6.9 IP?