7.3 that does not like to start

[steele86]

my coworker has a 99 7.3 6sp with 400k and its a ***** i told him its the glowplug he says no so im asking you guys

[audiocontr]

Simple test: cycle the glow plugs 2x before starting. If there is a difference, its glow plugs.

I would say its old injectors myself. be happy you got 400k out of it and throw some injector cleaner in.

[SuperCrutyPS]

It could be glow plugs. Let them stay on for the whole time. They stay on for about 2mins even though the WTS light goes out.
Another thing to try would be plug that mother in overnight to see if it starts better 'warmed up' -

It could the GPR not sending juice to GPs too. It's a relay so if it's not clicking in, the voltage doesn't get passed on.

I agree with audiocontr, if it ain't the GPR or GPs, try the injectors.

[dentexpowerstroke]

Originally Posted by audiocontr

Simple test: cycle the glow plugs 2x before starting. If there is a difference, its glow plugs.

I would say its old injectors myself. be happy you got 400k out of it and throw some injector cleaner in.

Oh ya cycle them? They stay on for 3 minutes there is no need to cycle them

[audiocontr]

Simply a quick way to count by allowing the light to turn off twice. The point is to allow more time for the glowplug to heat up before cranking. Deposits coating old glow plugs can lower their effectiveness. Regardless, i didnt think it was 3 minutes. Learn something new.

[steele86]

he cycle 6 times and still a ***** to start when its cold he almost drain the battery

[sean400]

does it crank over slow? or like a champ?

[jesilvas]

Batteries, clean connections, cables, starter connection, starter, GPR, GPs, UVCHs since they supply power to the GPs.

[QMartinez]

We had the same problem with a work truck that has 280,000 miles on it. It would take atleast 4 tries to start. It would smoke like crazy when it finally did start.

8 new glow plugs and it starts like a champ without being plugged in.

[GreenF350]

My question would be how does it act once it is started...smokey? What color? Smooth running or rough, etc. All this information would help diagnose the problem. For instance, when I first bought my truck and was ingorant to specifics about diesels I had a hard starting problem...The guy I bought it from said "just cycle the key two times and it lights right off". Said it was glow plugs. In the end, it was the starter. It didn't seem to crank slow to me until the new starter went in....Holy crap did it turn over faster! Had another friend with the same problem...Over time it just slowed down a little at a time until it didn't have enough to start it. Not saying that is the problem, but other things may be at play.

As far as the glow plugs....They stay on based off PCM's moitoring of oil temp and OAT. In warmer temps with the engine warm they don't even come on at all. When it is really cold they might stay on for a couple minutes.
-Aaron