2000 7.3 cold start issues
 

im a dodge man but the lady is a ford girl. everything seems to be working correctly(glow plugs,batteries good,) this thing will not start if its below 35 and its not plugged in

Try it plugged in. It is there for a reason

How do you know glow plugs are good? How bout the relay? What happens if you turn the key to the on position for 30 seconds and then try to start.

What have you checked/tested to see if the glow plugs are not working?

I'm betting the relay is dead.

I changed my starter, and that solved the cold start problem. Spins faster than the other one. :jump:

my truck is the same way. i just plug it in. had #8 injector bad, replaced it thinking that may have been the issue but same way. my relay is working, and the glow plugs were tested and they are working but my buddy said that they might be working but not putting out enough to start it when its cold. check the relay 1st when its cold, then go from there.

Hello All,
I'm a newbie to this forum.

I have a 2000 F-350 with a 7.3l, 149k
It don't like the cold, ( I live in Western New York), anytime under 35 degrees, won't start. I'll get a little putt out of one cylinder, then hit the gp's again for another putt. But it fires right up when plugged in. I bought the truck in Aug. of '10 with 128k. Don't know if gp's where ever changed. Also started missing real bad and the s.e.s light comes on. Seems like running on only 4 cylinders. I found another forum, several people had same problem ( loose plug inside valve cover) So I figure great, I'll pull the valve covers, fix the loose plug & replace the gp's. Well I pulled both VC's off, both plugs were tight. Changed out the gp's and in the process of putting the rest together.
My question is where is the gp relay and how do you test it ? I haven't fired it up yet, but I think my bad miss will still be there, any ideas ???? I pulled batteries out so I can't get any codes yet. Also where (is this dealer only item?) can I get the rubber o-ring/gaskets for the crank case vent ? mine is quite rusty, possibly replace it ?
Thanks for any input!
It's my first Diesel Truck.

Curbman....

^^ welcome. well when you had the VC's off, did you make sure the plugs going to the injectors were on tight as well as the GP's? the GPR is located pn the passenger side of the engine, about center of the oil rail. if you have a AIH, it is the relay that's closest to the turbo. put a test light on it. i'm betting this is your cold start problem. GP's don't go out near as often as everyone thinks they do.

yep what he said. it looks like a starter relay. should have hot going in all the time, and when cold, turn key on w/o starting and the 2nd big terminal should be hot. if not, no juice to glow plugs.

if the relay is bad, use a nut driver to tighten the nuts for the terminals. it is very easy to over tighten and break the relay. i speak from experience.

Living in Orlando Fla. I don't have an issue with 35 degress or lower, but I have had to start using my block heater due to a rough cold start in the A.M.. Truck has 250,000 miles on it!Runs smooth after it gets to operating temperature, if I don't use the heater, but the heater makes it ready right out if the box.

I have new GPs and the GPR but still struggled when unplugged. What changed and eased cold starting was 5-40 synthetic oil even when it was in the single digits unplugged. Still not good as my W123 300D Mercedes, specially when I changed the batteries. My MB (it has over 300K miles )starts even before the WTS light turns off when it is 10 or lower. I am going after batteries next but that would be like a $300 expense. We did some winter camping when we had a cold spell here in Northern NM (it was 0 at one point) and me and my wife just started the truck and let it idle for 5 minutes at 900 RPM at 9 PM, 12 AM and 4AM when the oil was still dino 15-40. We also carried a 800 amp battery pack with us.

The 5-40 synthetic seem to help with the rough idle and cackle as well. But I know guys here who don't buy the syn myth but they probably have new injectors or keep their strokes in tip top shape and they could probably use lard and get away with it.

problem fixed
 

Checked relay and it tested good so went to the glow plugs next. Found 4 not working one which was unplugged and the others only had like 2.4 resistance when tested. It was 29 degrees yesterday and truck started perfectly first cycle one changing all the glow plugs. :jump: just an fyi changing glow plugs is not and easy task make sure you have a day to spare.

Just changed out all 8 glow plugs and seemed like it fixed my cold start issue. Did not plug in the block heater last nite and it did not want to start normal. Plugged it in for a few hours and it fired right off. I live in Orlando, Fla. and it was not near 35 degrees last night. Just put fresh oil in also, 15w40 Rotella Diesel engine. Still runs rough during warm up, then smooths out for the rest of the day.

Check the relay.

You should not have any issues starting at 35*.

relay?
 

Did you check the relay?????? Mine was good so i checked the glow plugs second. There is 2 relays on the top of the engine the one closest to the cab is the gp relay when you turn the key on you should have 11+ volts to all the legs and none on the right leg when the key is off.

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FYI need to make sure you batteries are good before you look at relay or gp's. Looming at the simple things first will save you money and time. Its not always a huge issue its usually something small causing a huge problem.:argh:

Glow Plug relay seems good
 

I have just replaced all 8 of the glow plugs because I was experiencing a rough idle at cold start, sometimes did not want to start. Cold weather is not an issue here in Florida. Check the GPR with a multimeter just now and I have 12.65v at the large terminals with the key off. When the key is turned on, I now am testing the smaller wire terminals and watch the meter climb to roughly the same, 12.56v. Am I doing this right?:nope: Seems like the GPR is OK also. Just changed the motor oil with 14 quarts of Rotella 15w40 for diesel engines. After the truck warms up it seems to shift into a different power mode and smooths right out. Never have a problem the rest of the day.