Strange Starting Problem??

stillbuildin · Nov 29, 2016

Hey all, longtime lurker here and finally joined up. I've found tons of great info from members here in the past, I've owned several 7.3s - always like to have at least one around!

Anyway, my current is an 02 Crewcab Longbox Lariat Dually. 250k miles, rebuilt tranny. 4" Turbo back, otherwise Bone stock.

Here's the deal: on a cold start after sitting overnight unplugged with outside temps anything below 35F, it cranks over 6-8 times without firing at all. Cycling glowplugs twice at each attempt (until they click off). Then leave the truck for 15 minutes and it will start first try, almost instantly, with one glowplug cycle.

Any ideas on this one?

New gp relay, all 8 plugs tested on bench (Beru only), new starter, batteries tested good, harnesses bench tested good with 50 cent mod done.

Oil level and Hpop level good, no fuel in coolant.

It does have three injectors not working cold.

I don't have a Scanner although I've got Android and recently ordered a couple of those Bluetooth obd units (torque pro).

Any help would be much appreciated, I'm running out of ideas of what to check. Thanks!

ju015dd · Nov 30, 2016

I would put a voltmeter on it while cranking to see what voltage is looking like under load.

Justin@DP-Tuner · Nov 30, 2016

When cranking and not starting is it smoking white out the exhaust?

With that kind of mileage, I would suspect worn injectors.

stillbuildin · Nov 30, 2016

Ok thanks I'll give it a try tomorrow morning, although the batteries have tested good and starter is new. When I try it 6 times first it cranks strong and fast every time. But only fires once you leave it sitting for 15 minutes. I can't work out what could change while it's sitting dead for a time.

stillbuildin · Nov 30, 2016

Thanks Justin for responding, I haven't noticed any snooker at all but I'll watch it tomorrow morning and report back. I'm planning to have all the injectors rebuilt butt that won't happen till after Xmas. I guess that even if the other five are working cold, they might need that turning over to get them going. Might explain the several attempts then a period before firing?

stillbuildin · Nov 30, 2016

Ha I mean smoke. I don't even play snooker

ToMang07 · Nov 30, 2016

Have you tried a good synthetic oil? Makes a huge difference with cold starts.

stillbuildin · Nov 30, 2016

I only picked the truck up recently for cheap (wouldn't strat at all without being plugged in. I found three dead glowplugs and a melted harness connector. Changed those and checked all harness points. Pulled every glowplug and bench tested. It probably needs an oil change and I was gonna put 5w40 in just to see if it starts and runs better with something thinner....

stillbuildin · Nov 30, 2016

Thanks ToMang07, maybe I'll try a synthetic 5w40. Much prefer 15w40 but I guess winter's here anyway.....

TyCorr · Nov 30, 2016

ToMang07 said:
Have you tried a good synthetic oil? Makes a huge difference with cold starts.

Baaaaa....i agree but once i changed injectors it'll fire right off with 15-40 molasses lol

ToMang07 · Nov 30, 2016

TyCorr said:
Baaaaa....i agree but once i changed injectors it'll fire right off with 15-40 molasses lol

Listen.... mine only had 90k on it when I switched the first time.... HUGE difference at sub-freezing temps, especially 0 and below. It's only at 152k now, and I just switched from Delo to (15-40) Amsoil, cranks over in the morning like it was plugged in now! Below freezing with the Delo it would take forever to fire, then run like it's only firing on half the cylinders for a few minutes. And mine has (in the last year) new starter, batteries, GPR and glow plugs.

TyCorr · Nov 30, 2016

Mine runs delo too. I dont mind 4 romps in the morning. I dint even mess with gp's or the "heater" ive been hearing about the last two weeks. LOL

90k isnt alot but 17 years and 250k is.

Have you noticed is been all gp, oil, and hard start threads the last two weeks.

ToMang07 · Nov 30, 2016

TyCorr said:
Mine runs delo too. I dont mind 4 romps in the morning. I dint even mess with gp's or the "heater" ive been hearing about the last two weeks. LOL

90k isnt alot but 17 years and 250k is.

Have you noticed is been all gp, oil, and hard start threads the last two weeks.

'Tis the season, lol

stillbuildin · Nov 30, 2016

TyCorr said:
Baaaaa....i agree but once i changed injectors it'll fire right off with 15-40 molasses lol

Yep my last 01 was an excellent cold starter. Never needed plugging in and fired first time, every time. I had a 99 before that which was the best. Left it for a week once in -2f and it fired right up smooth....i want to try to make this one as good eventually

stillbuildin · Nov 30, 2016

ToMang07 said:
Listen.... mine only had 90k on it when I switched the first time.... HUGE difference at sub-freezing temps, especially 0 and below. It's only at 152k now, and I just switched from Delo to (15-40) Amsoil, cranks over in the morning like it was plugged in now! Below freezing with the Delo it would take forever to fire, then run like it's only firing on half the cylinders for a few minutes. And mine has (in the last year) new starter, batteries, GPR and glow plugs.

So should I bother with the 5 40 or just change it now to 15 40 Amsoil? Synthetic?

stillbuildin · Nov 30, 2016

Oh gotcha, Amsoil synthetic. Sounds like a plan......

stillbuildin · Dec 1, 2016

ju015dd said:
I would put a voltmeter on it while cranking to see what voltage is looking like under load.

So, volts are at 12.45 first, they drop to 11.7 when the key is turned on to warm up the glowplugs. It then drops to 10.54 when cranking.......?

stillbuildin · Dec 1, 2016

Justin@DP-Tuner said:
When cranking and not starting is it smoking white out the exhaust?

With that kind of mileage, I would suspect worn injectors.

Couldn't see any white smoke at all while cranking......?

ToMang07 · Dec 1, 2016

stillbuildin said:
So, volts are at 12.45 first, they drop to 11.7 when the key is turned on to warm up the glowplugs. It then drops to 10.54 when cranking.......?

If it's going to 10.5 or below the injectors won't fire. What CCA are the batteries you have? 850cca is the absolute minimum in cold states.

ju015dd · Dec 1, 2016

stillbuildin said:
So, volts are at 12.45 first, they drop to 11.7 when the key is turned on to warm up the glowplugs. It then drops to 10.54 when cranking.......?

How old are the batteries? I read you just put a new starter in but what brand? I bet it bust right off if jumping it from another vehicle.