Got a fella in camp with a 7.3 that has 479,000 miles. It won't start. It smokes out the pipe when he cranks it.I have already talked to him about my opinion.He disagrees. He just keeps charging the battery with a generator and continuing to crank it more. Says he just needs to give it a good 30 second crank to get it to fire up.I don't see it happening.Any thoughts?

I have no idea but, please keep us updated if he gets it started.With that many miles he's probably familiar with its quirks.

If that's the diesel, sounds like the glow plugs aren't working.

x2 I had one, was a very good engine back in 1991

There was a recall on the 7.3L cam position sensor. If the CPS went bad it wouldn't start or run. They'd be running down the road just fine then quit. Really simple and cheap to replace. Cost is about $20 on line for the CPS. Just need a 10mm socket and probably a flat blade screwdriver to pry it out. There are some videos on YouTube showing how.Before the recall it was common for guys with the 7.3L to carry an extra CPS.

7.3 no start | Good Sam Community

Turtle_n_Peeps
Explorer
Jan 22, 2017
Airstreamer67 wrote:
The in-line engine design has certain operating advantages, as do the V-shaped and the H-shaped and the round-shaped and whatever-shaped engine design out there. However, the design shape of the engine, per se, incorporates nothing magical about it that adds to its longevity.

I remember arguments about the 5.9 I-6 Cummins having a longer design life compared with the 7.3 V-8 International. Yet the manufacturers designed and built them for the same class of usage and the same predicted life before overhaul, and hundreds of thousands of 7.3s in school buses, medium trucks and pickups proved that, and they are still proving it to this day.

Well said and 100% correct. There is nothing magic about and inline that makes it last longer than a V or any other shape.

Now; rod to stroke ratio or RPM? Yep, that has a lot to do with it.
Airstreamer67
Explorer
Jan 22, 2017
The in-line engine design has certain operating advantages, as do the V-shaped and the H-shaped and the round-shaped and whatever-shaped engine design out there. However, the design shape of the engine, per se, incorporates nothing magical about it that adds to its longevity.

I remember arguments about the 5.9 I-6 Cummins having a longer design life compared with the 7.3 V-8 International. Yet the manufacturers designed and built them for the same class of usage and the same predicted life before overhaul, and hundreds of thousands of 7.3s in school buses, medium trucks and pickups proved that, and they are still proving it to this day.
Huntindog
Explorer
Jan 22, 2017
dieseltruckdriver wrote:
My point is your saying a V engine is only good for 250,000 miles. Obviously not correct, except maybe in cases of neglect. Your Cummins bias is showing here. ;)
As a general statement, it is correct. There is actually a rating for engine life IIRC, it is a "B" something or other.
And I seem to recall that both Ford and GM were in the 200-300K range.... Obviously a true big rig motor will be longer.... But then again, that isn't the point of this thread. We are talking about pickups here.
dieseltruckdriv
Explorer II
Jan 22, 2017
My point is your saying a V engine is only good for 250,000 miles. Obviously not correct, except maybe in cases of neglect. Your Cummins bias is showing here. ;)
Wild_Card
Explorer
Jan 21, 2017
dieseltruckdriver wrote:
Wild Card wrote:

I am with you. A "V" configuration diesel engine only has a 250,000mile before a major failure lifespan. Yes they regularly go to 500k and beyond with meticulous maintenance.

Not true. The Cummins fans might want to look up the 903. One of the first semi tractors I drove had a 903.

Know all about Cummins 378,504,555 and 903. My dad retired Cummins tech. No different than a Detroit V series engine. What's your point? A V series engine will not last as long as an inline. Be it Izuzu (Duramax), Ford, International, Cummins What ever.
dieseltruckdriv
Explorer II
Jan 21, 2017
Wild Card wrote:

I am with you. A "V" configuration diesel engine only has a 250,000mile before a major failure lifespan. Yes they regularly go to 500k and beyond with meticulous maintenance.

Not true. The Cummins fans might want to look up the 903. One of the first semi tractors I drove had a 903.
dieseltruckdriv
Explorer II
Jan 21, 2017
If it is smoking, it isn't the CPS. It is easy to check by watching the tachometer while cranking it over. If the tach moves, the cps is good.

I am on my second 7.3 Powerstroke, and have to agree with everyone that is saying glow plugs. That is how these things act with weak or bad glow plugs. He got bent over spending $500 on a $50 dollar relay, but may have had other things done or checked while it was in for that. It is easier to ohm the glow plugs than use a wire to look for sparks, using an ohm meter will check the plug in the valve cover gasket, and the wiring under the valve cover.

Speaking of valve covers, most here probably do not know how much it takes to remove the passenger side valve cover.

If he has access to power, plug in the block heater, that will warm up the engine enough to start with even without glow plugs. If it won't start then, I would blame compression.
transamz9
Explorer
Jan 20, 2017
hone eagle wrote:
From memory - the ECM looks for 500rpm while cranking before fuel is activated ......499rpm and you get a no start.

Yes, I agree. There was very little change in the cranking of it but a big change between starting and not. LOL
hone_eagle
Explorer
Jan 20, 2017
From memory - the ECM looks for 500rpm while cranking before fuel is activated ......499rpm and you get a no start.
transamz9
Explorer
Jan 20, 2017
nevadanick wrote:
Then its not turning over fast enough.

I had a 93 that did this. It cranked fine but didn't have enough juice to fire while the starter was pulling juice from the batteries. I could put jumper cables on and it would fire right up with very little change in the cranking speed. I put new batteries on and had no more starting problems.

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