Hard to start when cold!?! [Archive] - TheDieselPage.com Forums

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arveetek

11-14-2006, 09:10

My '81 project truck has decided it doesn't want to start when cold. This morning, it was only 46 degrees out, but it put up a struggle to get started. I first noticed the problem last week, and after some troubleshooting, discovered I had two burned-out glow plugs. I installed a new set of Kennedy's Quick Heats, but it hasn't helped.

The truck starts great when warm, and starts great when plugged in. My homemade glow controller energizes the plugs for about 12 seconds. The engine cranks and cranks and then slowly starts firing on one cylinder and then the next. It then starts with a huge cloud of white smoke. Again, if I plug it in, it starts instantly with little smoke.

It started great last winter. The only thing that's changed since then is that I replaced the direct-drive starter with a later model 6.5L gear-reduction starter. It doesn't really sound to me like it's turning over slower, but perhaps it is. Has anyone else noticed this kind of issue? Maybe the gear-reduction starter coupled with the 19.75:1 compression is causing the hard starting?

One thing I haven't checked yet is to make sure that all 8 plugs are receiving good voltage and current. Visually, the wiring looks good, and I know that at least some of the plugs are being energized, but there is a remote chance that maybe not all...

Casey

wthif

11-14-2006, 15:10

arveetek

11-14-2006, 15:32

Casey,
Do you know if your advanced timing is working? I'm having similar problems and my temp switch for the advanced timing isn't working. Will be replaced soon. Oh do you have a tach and does it work while you are cranking the engine?

One last thing are you holding the throtle pedal down at all while cranking? I've found in could temps 1/2 throttle helps a lot.

Yep, cold advance is working, it makes an awful rattle until it warms up and kicks off. I have tried various throttle positions, even full throttle, but all that does is make the engine rev way up when it finally does start. I don't have a tach, though.

Casey

kconnair

11-14-2006, 19:19

I am having a similar problem to Casey's. Started fine last winter after I advanced the pump, and fixed the cold advance - wondering if the timing chain is on it's last legs? The truck doesn't rattle quite like it did earlier this year, It sounded almost like a PS when the cold advance was on. Still rattles, cold, but almost not at all when warm.

Just almost impossible to start below 45 unless plugged in.

Could it be the chain?

Was planning on replacing it anyway.

Any thoughts?

Kevin.

wthif

11-14-2006, 19:49

Casey,

Did you try giving your truck a diet and let it run some dino diesel and see if the problem is the same? Just a thought. I hope the bio diesel isn't the problem.

Also no fuel leaks right? Bio finally chew through some old rubber fuel lines.

Robyn

11-14-2006, 22:45

How many miles are on the injectors??
If they get tired they dont spray a fine mist they squirt a stream and then the engine starts hard

john8662

11-15-2006, 01:13

Install the clear line on the return of the IP and have someone start the truck while you watch, bone cold. Or vice versa.

I'm going to jump in and fix my small air leak on my '91 burb as soon as I get time tho.

I also vote for the gear reduction starter being a small part of this...

J

arveetek

11-15-2006, 08:14

Well, it looks like I got ahead of myself a bit on this problem! It was a simple fix: I found a broken wire on the glow plug harness, so only the driver's side bank was glowing. With only 4 glow plugs working, no wonder it didn't like to start! When I checked the plugs the other night, I know had voltage on both banks, but I probably jiggled one of the wires when replacing the plugs.

Anyway, she fired right up this morning like it was 90 degrees out.

I really ought to get a new glow plug harness....mine's been through a lot of cycles and is starting to show the wear.

Casey.