1990 7.3 cam positioining sensor
Senior User
Joined: Sep 2007
Posts: 317
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From: Snohomish, WA
The IDI does not have a cam position sensor, but it does have a engine speed sensor, which feeds data to the tach and the transmission. It is a magnetic type sensor that goes out from time to time. It is located to the driver's side of the Injection Pump gear cover, near where you put the oil in. It looks like a big bolt with two wires coming out of it.
If it is not working it will cause the E4OD automatic transmission to shift poorly in limp-mode. I don't think it will prevent the truck from starting, so the start issue is probably something else.
I'm assuming the truck will turn over, but not start.
Did truck run before? It is just not starting all of the sudden? Is it totally dead, or is it just starting really hard? Are all three wires that go to the top of the injection pump hooked up? Is the throttle position sensor on the driver's side of the injection pump connected?
There is very little in the way of electronics to prevent the IDI from running, so my guess is that you have some sort of fuel problem. Is there diesel in the fuel filter?
If it is not working it will cause the E4OD automatic transmission to shift poorly in limp-mode. I don't think it will prevent the truck from starting, so the start issue is probably something else.
I'm assuming the truck will turn over, but not start.
Did truck run before? It is just not starting all of the sudden? Is it totally dead, or is it just starting really hard? Are all three wires that go to the top of the injection pump hooked up? Is the throttle position sensor on the driver's side of the injection pump connected?
There is very little in the way of electronics to prevent the IDI from running, so my guess is that you have some sort of fuel problem. Is there diesel in the fuel filter?
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Freshman User
Joined: Dec 2004
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From: Powhatan Va.
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I had problems starting, crank forever before it will start, changed glow plugs, helped alittle, changed injectors and started like new, next morning hard to start like before and when I put it in drive it would not go to into first, like takeing off in overdrive, and shift into reverse real hard,
Senior User
Joined: Sep 2007
Posts: 317
Likes: 0
From: Snohomish, WA
I had problems starting, crank forever before it will start, changed glow plugs, helped alittle, changed injectors and started like new, next morning hard to start like before and when I put it in drive it would not go to into first, like takeing off in overdrive, and shift into reverse real hard,
You have two issues.
1) Start issue
2) transmission
Starting issue
The starting issue sounds like you are getting air into the fuel return lines. Did you change them and the Ts around the injectors along with the O-rings when you did the injectors? before you start it in the morning, pop the fuel filter, if it is dry the return lines are definitely letting air into the system which allows the fuel to drain back into the tank. When you go to start the whole system needs to refill will fuel to start. Changing out the return lines/Ts/O-rings will likely fix this.
Transmission
Is the OF Off light flashing on the transmission? If it is, the computer that controls the E4OD has logged a trouble code. If you pull the code it might help solve the problem.
I'm assuming the transmission has the correct fluid level.
Is this a new truck to you? Did the transmission ever shift correctly, or is it a new issue?
Fleet Owner
Joined: Jul 2006
Posts: 20,373
Likes: 841
From: Mi'kma'ki
warning!
once you fix the hard start problem do not attempt to drive the truck with non working tach sensor with the E40D transmission.failure will result,and most likely will cost you a tranny.
i would personally not even shift the trans from park until its fixed (tach senor wiring inspected/repaired and or tach sensor replacement.)
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Freshman User
Joined: Dec 2004
Posts: 26
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From: Powhatan Va.
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changed the tack sensor and trans is working ok. when trying to start it will start right up and then cut off then have to crank for a long time before it will start thanks for all the help yall Capt. Hugh
Senior User
Joined: Sep 2007
Posts: 317
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From: Snohomish, WA
This sounds like it could be a lift pump. I would check the flow rate at the schrader valve as detailed above.
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Logistics Pro
Joined: Sep 2007
Posts: 3,737
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From: Western Mass
It sounds exactly like the return lines are leaking. Do a search, its been covered a million times. If you didn't change the o-rings when you did the injectors, air is leaking in after shutdown pulling the fuel back to the tank. The little fuel left in the injection pump and hard lines will let it start, then die instantly when they run out of fuel.
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Fleet Owner
Joined: Jul 2006
Posts: 20,373
Likes: 841
From: Mi'kma'ki
though i wont yell "NO!" 
i do agree,it sounds like classic air intrusion.start - die - hard restart.
good call getting that tach sensor right in.
always good to hear when you may have just saved someone upwards of a couple grand.
i do agree,it sounds like classic air intrusion.start - die - hard restart.
good call getting that tach sensor right in.
always good to hear when you may have just saved someone upwards of a couple grand.
Cargo Master
Joined: Mar 2010
Posts: 2,227
Likes: 149
From: Higginsville, MO
take a filter wrench and unscrew it and look down in it if its not full to the top with fuel the return lines are leaking
Cardone Reman/Fuel Injector (2K-202) | Fuel Injector | 1994 Ford F250 3/4 ton P/U 4WD 8 Cylinders M 7.3L Diesel | AutoZone.com
this is what you need its more expensive one. the one at pensecola diesel is like 40 bucks or something but this link was readily available and im not a fan of waiting for things to ship to me. if i need a part i usually just call autozone and get it the same day or next morning but thats just me. i used this kit and have no problems with it
Cardone Reman/Fuel Injector (2K-202) | Fuel Injector | 1994 Ford F250 3/4 ton P/U 4WD 8 Cylinders M 7.3L Diesel | AutoZone.com
this is what you need its more expensive one. the one at pensecola diesel is like 40 bucks or something but this link was readily available and im not a fan of waiting for things to ship to me. if i need a part i usually just call autozone and get it the same day or next morning but thats just me. i used this kit and have no problems with it
Senior User
Joined: Sep 2007
Posts: 317
Likes: 0
From: Snohomish, WA
Honestly, I think your problem is most likely leaking fuel return lines/o-rings at the injectors. I would replace them all, and see if you still have an issue. A kit to change all the return lines, T's, and O rings is like $50.
Usually when you pull the injectors it is best to change them, or at least the O-rings.
Logistics Pro
Joined: Sep 2007
Posts: 3,737
Likes: 179
From: Western Mass
take a filter wrench and unscrew it and look down in it if its not full to the top with fuel the return lines are leaking
Cardone Reman/Fuel Injector (2K-202) | Fuel Injector | 1994 Ford F250 3/4 ton P/U 4WD 8 Cylinders M 7.3L Diesel | AutoZone.com
this is what you need its more expensive one. the one at pensecola diesel is like 40 bucks or something but this link was readily available and im not a fan of waiting for things to ship to me. if i need a part i usually just call autozone and get it the same day or next morning but thats just me. i used this kit and have no problems with it
Cardone Reman/Fuel Injector (2K-202) | Fuel Injector | 1994 Ford F250 3/4 ton P/U 4WD 8 Cylinders M 7.3L Diesel | AutoZone.com
this is what you need its more expensive one. the one at pensecola diesel is like 40 bucks or something but this link was readily available and im not a fan of waiting for things to ship to me. if i need a part i usually just call autozone and get it the same day or next morning but thats just me. i used this kit and have no problems with it
Pensacola Fuel Injection | Worlds #1 Diesel Rebuilder - FORD 6.9L - 7.3L :: INSTALLATION KITS
Also several other sets on ebay for free shipping at $23-25... If you want to pay twice as much at autozone, go for it.
In all honesty, most people can reuse the caps and just replace the fuel line and o-rings. McMaster Carr has viton o-rings, #111 for like $6 for a pack of 50, and fuel line is cheap at autozone (etc...).
He probably doesn't NEED the more expensive one, probably just o-rings and hose. When I put the turbo on my truck last year, all I did was swap out the one cap in the back to change the routing, and redid the hoses and o-rings from McMaster Carr. I probably spent like $15 and had to wait like 2 days for the o-rings (which I had ordered in advance so it wasn't an issue). My caps were originals with 22 years and 190,000 miles and they have worked just fine with the new o-rings
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