International 7.3 IDI no start

[Jeff-C-IL]

Friend of mine bought a '93 Ford Superduty with only 65K miles on it.....no rust, interior/seat looks like new, fancy handicapped "doctors office" built into the box on the back, so I believe the mileage.

The truck has been sitting for 8-10 years, and won't start at all.   I was helping him work on it last night and we have done the following:

• New batteries. 
• Electric pump from a jerry can with new fuel, new filter, and fuel bled all the way thru to the injector pump.
• The shutoff solenoid in the pump clicks when you take the wire on/off.   Both connections at the pump have 10-12V on them.
• All injector lines were cracked, some fuel comes out, every line got wet. (may not be enough - it did not "blast" out as the engine cranked?)
• Checked glow plugs, 7 of 8 are good.  10-11V at the plugs when the controller is on.  The controller comes on for 5-8 seconds, then cycles.  I also directly jumped the relay for 20 seconds before a crank cycle.  No change.
• We felt it was cranking too slow, so replaced the starter.  It turns over pretty good now.  Adding a jump pack and a jumper to another vehicle did not change crank speed or voltages at all.
• No smoke at all comes out the exhaust.
• We tried a tiny shot of ether - engine backfired into the intake and ether burned off inside the intake.  Pretty sure it just ignited on a glow plug.  We unplugged the glow plugs entirely and tried more ether - nothing whatsoever, engine does not even try to pop.
• The engine cranking sounds pretty normal, has a bit of a "thump" as it cranks with the air cleaner off, sounds a bit like a sticky valve thumping into the intake, but after listening to some you-tube videos some other trucks sounded that way too.

Any ideas what to try next?   Pull the pump & injectors?   Timing chain?   How do you check timing on these engines anyway?  I never worked on one before.   Compression?

[dale560]

43 minutes ago, Jeff-C-IL said:

Friend of mine bought a '93 Ford Superduty with only 65K miles on it.....no rust, interior/seat looks like new, fancy handicapped "doctors office" built into the box on the back, so I believe the mileage.

The truck has been sitting for 8-10 years, and won't start at all.   I was helping him work on it last night and we have done the following:

• New batteries. 
• Electric pump from a jerry can with new fuel, new filter, and fuel bled all the way thru to the injector pump.
• The shutoff solenoid in the pump clicks when you take the wire on/off.   Both connections at the pump have 10-12V on them.
• All injector lines were cracked, some fuel comes out, every line got wet. (may not be enough - it did not "blast" out as the engine cranked?)
• Checked glow plugs, 7 of 8 are good.  10-11V at the plugs when the controller is on.  The controller comes on for 5-8 seconds, then cycles.  I also directly jumped the relay for 20 seconds before a crank cycle.  No change.
• We felt it was cranking too slow, so replaced the starter.  It turns over pretty good now.  Adding a jump pack and a jumper to another vehicle did not change crank speed or voltages at all.
• No smoke at all comes out the exhaust.
• We tried a tiny shot of ether - engine backfired into the intake and ether burned off inside the intake.  Pretty sure it just ignited on a glow plug.  We unplugged the glow plugs entirely and tried more ether - nothing whatsoever, engine does not even try to pop.
• The engine cranking sounds pretty normal, has a bit of a "thump" as it cranks with the air cleaner off, sounds a bit like a sticky valve thumping into the intake, but after listening to some you-tube videos some other trucks sounded that way too.

Any ideas what to try next?   Pull the pump & injectors?   Timing chain?   How do you check timing on these engines anyway?  I never worked on one before.   Compression?

This is a stanadyne or Roosa pump? Not a power stroke? If it is older style with mechanical pump your pump is gummed up or rotor drive sheared off. Newer one I  can’t help much.

[dale560]

If this style you can remove oil fill spout and observe gear to make sure timing gears are rotating.

[Dirt_Floor_Poor]

If the engine doesn’t do something on ether, I think I would take a valve cover off and see if things are moving. A little bit of ether usually goes a long way on those IDI’s. We’ve had engines with inoperable glow plugs for years at a time and you can still get them started on ether when it’s pretty cold out. Since that one hasn’t been started in a while it may be different, but if it’s cranking over good and a shot of ether doesn’t do anything it doesn’t really sound like a pump problem. 

[Jeff-C-IL]

To be clear, this is pre-powerstroke, the mechanical pump.   When you crack the injector lines, the fuel does bubble out as you crank the engine - it just seems a little weak bubbling as the fuel slowly seeps out over the fitting.   I'm used to the DT400 engines when you crack a line fuel squirts out like a fountain!    

[dale560]

1 hour ago, Jeff-C-IL said:

To be clear, this is pre-powerstroke, the mechanical pump.   When you crack the injector lines, the fuel does bubble out as you crank the engine - it just seems a little weak bubbling as the fuel slowly seeps out over the fitting.   I'm used to the DT400 engines when you crack a line fuel squirts out like a fountain!    

Sorry I forgot to save my above post. If no fuel is shooting out you  (A) either have to make sure fuel is getting to injector pump. Crack inlet on pump see if charge pump is working. More than likely internal parts sticking on pump.

[jass1660]

Gummed up delivery valve in pump, no smoke out exhaust equals no fuel in cylinders.

[stronger800]

Tap on the pump with a big screwdriver 

[MarkG]

Ether can be hard on those engines. But without glow plugs they are impossible to crank without ether. Try WD-40 sprayed straight into intake with filter assembly removed. Do this with glow plugs working and while engine is cranking over. If it starts keep giving short blast of WD-40 to keep it running for a bit. Also make sure there is more than 1/4 tank of fuel. Those trucks were notorious for the pickup screen breaking off. When the screen breaks off it starts sucking air at 1/4 tank. Good luck. Sounds like you got a great truck!

[TomH]

Fuel filter in good shape and a good amount of fuel out of the filter schrader valve?

[1958560]

If manual trans, try pull starting. May take a while to get injection pump working. Timing gears rarely give trouble. Sounds like an injection pump fuel problem. We have had good luck with royal purple diesel injector cleaner. If you can get it to fire, fill fuel filter with royal purple and get started for 30 seconds to get treatment into the injection pump then shut off and let soak overnight. Then start next day and drive it with remaining treatment in half tank of fuel or less. Also remove the return line and try to start, possibly plugged or restricted. Could also remove top cover on injection pump to make sure the linkage is free and solenoid is able to do its job?

[SDman]

Your description of it not firing with ether reminds me of a couple 7.3L IDIs that had sat around for an excessive amount of time that we had at the auto shop years ago when I worked for my old boss. We felt enough oil on the cylinder walls had drained back into the crankcase that the rings were not sealing properly....low compression. IIRC, those old IDIs were north of 20:1 for a compression ratio...so a lack of oil on the cylinder walls made it that much worse. We used WD-40 like MarkG described above to spray into the intake manifold so the engine would at least try to run on its own and get all the parts lubricated with oil again and try to get some oil splashed up on the cylinder walls to help the rings seal. Another thing I have seen tried is to use some Marvel Mystery oil in a pump spray bottle that you spray down the intake while cranking.

[Jeff-C-IL]

All good suggestions.   The old tank and lift pump are disconnected, and an electric pump is being used.  A solid stream of fuel comes out the Schrader valve. 

Next time my friend is here (truck is parked at my farm), we will try some of these - taking the pump top off and checking for solenoid operation is a good idea.

[Diesel Doctor]

1 hour ago, Jeff-C-IL said:

All good suggestions.   The old tank and lift pump are disconnected, and an electric pump is being used.  A solid stream of fuel comes out the Schrader valve. 

Next time my friend is here (truck is parked at my farm), we will try some of these - taking the pump top off and checking for solenoid operation is a good idea.

And wiggle the metering valve to make sure that is not stuck?

Hopefully it was parked long ago and it does not have ultra low sulfur diesel in it?

[Injpumped]

If sitting that long, it's about a guarantee the pumping plungers in the pump are stuck, metering valve and delivery valse as well. Take top off pump to look inside, and if it looks like it's full of sewage, get it off and have it serviced properly. If it's nice and clean inside(doubtful with modern fuels) try freeing the metering valve up to see if it'll start pumping. The absolute worse thing you can do is try pull starting a dead engine (if it's a manual trans) that doesn't want to start. Usually forcing one to come out of retirement ends up with more expensive repairs due to it eventually seizing up because of the contaminated fuel. 

[dale560]

3 hours ago, Injpumped said:

If sitting that long, it's about a guarantee the pumping plungers in the pump are stuck, metering valve and delivery valse as well. Take top off pump to look inside, and if it looks like it's full of sewage, get it off and have it serviced properly. If it's nice and clean inside(doubtful with modern fuels) try freeing the metering valve up to see if it'll start pumping. The absolute worse thing you can do is try pull starting a dead engine (if it's a manual trans) that doesn't want to start. Usually forcing one to come out of retirement ends up with more expensive repairs due to it eventually seizing up because of the contaminated fuel. 

The best advice given. Those pumps aren’t that bad to pull off. It would be best to start with everything fresh.

[Jeff-C-IL]

This truck is an auto, so no pull start!   Can anyone give me a quick rundown on how to pull the pump properly on these - ie how to time it so it goes back on right?   Where are the marks, etc?   (I've learned not to pull a pump until AFTER you set it to the correct timing mark....makes reinstallation SOOO much easier.) 

Inj - Whats it typically cost to have one of these pumps checked out and cleaned up?    Low enough miles the pump should be in pretty good shape otherwise.  Also, how about the injectors, are they susceptible to gumming up & sticking as well, or is it likely just the pump?

My buddy actually has a whole different pump & injectors set he got off a running truck that was sent to the wrecker yard, but they would have way more miles on them.  Almost prefer to get this one rebuilt.

Still doesn't explain why it won't pop on ether.....but....sure hope its the pump, not something deeper.

[Injpumped]

taking a 6.9/7.3 pump off is pretty easy. Take all the lines off at the injector ends, no need to mess with pump end yet. Take oil fill tube off and you'll see the 3 bolts and a dowel. remove those and the 3 mounting nuts, inlet and return lines, and throttle, wires, and remove the pump and lines as an assembly. The timing mark is on top of the mounting flange. I'd stick the running pump on it and see if it'll run. Low miles really isn't a huge benefit on these pumps, as the advance are wears about the same and costs about the same to fix either way. These are typically around 800 in my shop as long as it's not seized. I only see about 1 or 2 automotive DB2's a year anymore. Not many left out there lol! 

[dale560]

The only thing I would add to Ed’s tutorial is if the newer 93 is like older engines they had a plastic port on top of injector. The return lines Hooke to it. Don’t remove these if dry but any sort of leak suspected remove and replace orings underneath. When you have inj pipe off real easy to access. But never mess with them if not leaking. They let fuel drain back and start really hard if leaking

[MarkG]

20 minutes ago, dale560 said:

The only thing I would add to Ed’s tutorial is if the newer 93 is like older engines they had a plastic port on top of injector. The return lines Hooke to it. Don’t remove these if dry but any sort of leak suspected remove and replace orings underneath. When you have inj pipe off real easy to access. But never mess with them if not leaking. They let fuel drain back and start really hard if leaking

Return line kit is so cheap I would definitely do it while the pump is off. These pumps are cheap on the internet but I would get yours rebuilt by a reputable shop. I installed a cheap rebuilt pump on mine and every time I took my foot off the accelerator too quick it would die.

[Jeff-C-IL]

5 hours ago, Injpumped said:

taking a 6.9/7.3 pump off is pretty easy. Take all the lines off at the injector ends, no need to mess with pump end yet. Take oil fill tube off and you'll see the 3 bolts and a dowel. remove those and the 3 mounting nuts, inlet and return lines, and throttle, wires, and remove the pump and lines as an assembly. The timing mark is on top of the mounting flange. I'd stick the running pump on it and see if it'll run. Low miles really isn't a huge benefit on these pumps, as the advance are wears about the same and costs about the same to fix either way. These are typically around 800 in my shop as long as it's not seized. I only see about 1 or 2 automotive DB2's a year anymore. Not many left out there lol! 

So I assume that the pump only goes back into the gear one way then?   Slip it back into the gear and line the marks up on the flange and it should be in time?

[Injpumped]

yep, pump hub has a slot the dowel in the gear goes into. Looks a lot like a CAV hub if you've seen those.

[nepoweshiekfarmalls]

Does it have a crank sensor?  I knocked a wire off my 95 changing the serpentine belt and it would not fire. New sensor, problem solved. 

[jass1660]

1 hour ago, nepoweshiekfarmalls said:

Does it have a crank sensor?  I knocked a wire off my 95 changing the serpentine belt and it would not fire. New sensor, problem solved. 

No, idi’s were pretty primitive.