glow plugs

[HRS PLY]

I have a hard start problem. if the truck get below 20* it dont want to start without cycling the plugs twice. if its plugged in it not a problem

I checked the relay and its sending power to the GP's the voltage on the batteries drops to 10.7 when the plugs are engerized. goes back up when they cycle off. I ohm'd the GP's and got 3.7 ohms on all of them. That seems a bit high on the GP's

what do you guiys think?

[HRS PLY]

ne1????????????????????

[NoRalPh]

OK First, what do you mean by "cycling the plugs twice"? You're not just waiting for that stupid light - right? It has Nothing to do with the amount of time the plugs are energized. They are ON for 2mins at those temps (Long after the light goes out) Try just leaving the key on for 90 secs and then crank it over.

Next your voltage drop shows the plugs are working and, 3-1/2 Ohms sounds high but, if there All at that, then there's No Way they're All in the same state of dieing (more likely how you're measuring them).

Under 20 is always going to be a hard start and the very reason you have a block heater. You always should use it, if you can, if it's going to be that cold. If you're turning the key On/Off with the WTS you'll notice an improvement by leaving it On longer I think. Are you running 15w oil? 5w Synthetic would help if you're not able to plug it in.

[HRS PLY]

yesterday it was in the upper 40's. I watch the voltage on the relay. It was on a good 10 seconds after the wait to start light goes out. I had no idea it could stay on for up to two minutes if needed. Same relay?

I measure the GP's by using my voltmeter. grounded it to the relay mounting bolt and went to the valve cover harness. all the plugs read the same. I thought they should vary but the didn't.
when its real cold I will let it glow for 60 seconds or so then try it again. I will try waiting like you said and see if it improves. I have 15w 40 standard oil in it right now.

thanks for you imput.

[NoRalPh]

Yup, same relay, controlled by the PCM (as is the WTS light) and kept on longer by how cold the engine is (sometimes the WTS light is on Without the GPs being on at All!)

If you have an outlet nearby, the best thing you can do is to get a Timer (RadioShack has a 15A digital that I use) and set it for 3hrs before you're be starting in the morning. Then, anytime it's going to be say, under 25, just plug it in and let the Block Heater do it's job. That's what I do, above 25 and I let it sit with the GPs activated for 90secs or so (a pretty long time.....) before I start. Below that I plug it in. Starts real well that way, fast warm-up, easier on the Starter & Batteries too!

[letitsno]

Also check your batteries, dirty terminal on drivers side battery, reads 590cca (850cca) on tester. Had a dirty terminal, going to fix terminal, run & retest. Was have slow cold start when not plugged in. Going snowmobiling next weekend if any snow left. No place to plug in were we are staying.

Update ok drivers battery at 590cca, passenger side at 115cca. So I am going to retest shortly, truck has a 250amp alt. on truck for snowplowing.

[letitsno]

I would check your batteries as mine are toast one stays around 575-590.
Other one did take charge and was at 575, checked 30 min later and was down to 450. Weak batteries are hard on the injectors & glow plugs might not be getting enough power. Two new batteries tomorrow.
8 years & batteries are toast what the hell. LOL
175k & 4 years of plowing, getting new motorcraft ones.

[shiz big red]

Batteries should be 850cca minimum. Get the Stancor relay. And use rotella 5w40 I never plug my truck in above when its above 10 outside and she fires right up no lope no smoke she starts and runs like a beast. Left her sitting for a week unplugged while on vacation it got down to mid teens every night and mid 20s during the days came home after nine days away and after waiting 30 seconds after wts light went off she fired right up no problem.

Sent from my ADR6350 using Tapatalk

[HRS PLY]

thanks for the imput guys