Hello to all. I have a 99 6.5 that has acquired a rough cold start cycle. Overnight temps don't matter. If it sits over night it will start right up but will not idle up for about 3-7 seconds. White smoke and stumbling would best describe the process. I have replaced the glow plugs(60Gs), checked the glow plug relay, cleaned and re-crimped the connector terminals and ohmed the harness. Truck has just 126,000 miles. Lift pump has been replaced, OPS is functioning. Any ideas would be great. Heath Diesel remote PMD on its way. They have been way more than helpful. Just wondering if anyone else had similar problem and have found a fix. I can't park this beast in my attached garage. Thanks in advance

Mine does the same thing,most of these older diesels, ie. john deere, caterpilar, or GM 6.5 they all hammer and run a but rough when cold at first start up and smoke a bit.

If the glow plugs are good, (and based on what you said I think they are) then your injectors may be bleeding down overnight. I think that is what my truck does. My GM tech buddy says that it is also possible that the injection pump leaks internally although I have never heard that anywhere else.

Once the truck starts and gets past it's 5-10 seconds of stumbling, it works great all day long. My fuel milage has been decreasing, but no signs of a knocking injector. Might not be a bad investment though.

I'm not sure what glow plugs were stock on a 99, but the #60 plugs need a bit more time to heat up enough. I built a manual over-ride to extend the glow time on mine. If I start it without giving it extra glow time, it does the same as you describe.
Ted

Does your amp draw during WTS indicate that the glow plug circuit is working properly? Your symptoms definitely point to glow plug duration or leaky injectors.

I am having the same issue as you Lance. Except along with the 60G glows I also put in brand new Delphi injectors. It still smokes and shudders on start up. I have noticed one thing. Mine is a 95' though so the coolant setup is different. Maybe someone with a newer engine can chime in. If i unplug my coolant temp sensor and the engine is completely cold, it does start better (more glow time as computer defaults to -40) when sensor is unplugged. As far as I know, the batteries are good, glows and injectors are new. The only thing left is glow time. That is something I am considering. There is a great post done by ChrisK1500 with instructions and parts list for manual glow plug controller. One of the topics in the first couple pages has it.

However, even if this fixes the issue for me, I'm not sure what made the cold starts bad to begin with. Before I touched anything it started rough. That's what made me throw parts at it in the first place. I guess I'm trying to say that it could be your injectors, but they may not be the root problem. Replacing them is a good idea when they get older. Improper burn hurts fuel economy and the pistons if the problem is bad enough. I doubt yours are at that stage though.

Just plug in the heater on a timer for about 2 hours before you get up in the morning.

I have about 2.2 volt drop at the glow plug relay when they are cycling. I was told that anymore than 2 volts and things are working ok. This whole problem is getting to me. It used to start right up and run great with-out any stumbling and very little smoke. I wish I knew what changed and why. Trying to solve this problem is getting pricey. Thanks for all the help. Any more ideas would be great.

By the way, mine does start a little better with the temp sensor un-plugged. Replaced that and plugged back in...same thing.:mad:

By the way, mine does start a little better with the temp sensor un-plugged. Replaced that and plugged back in...same thing.:mad:

That got you extra glow time, so I would go for the manual override switch like suggested above. I had the 60G glow plugs and had the same problem and the manual override worked great.

^^What he said. The temp sensor tells the computer what the ambient temp is outside. Unplugging tells the computer to assume that it is -40* and therefore the glow plug time is extended. If you replaced the glow plugs, you may not have had the 60g previously, and the glow plugs didn't need extra time. 60g's take longer than the stock glow plugs in many trucks, creating the need for a manual override.

Ditto the roughness with 60G's Just changed mine and have a similar issue.
Wonder if there is a glow plug relay for them with a longer glow cycle?

The nice thing about the override is you only use it when you need the extra time, which for me is the first cold start of the day. Other times the 'puter does the timing.

Has anyone tried the Bosch Duraterm glow plugs and had better results than the 60G's. Could a person rig a push button switch for the manual override set-up. I think I've seen the post and pics of the set-up. Thanks

"Could a person rig a push button switch for the manual override set-up. I think I've seen the post and pics of the set-up. Thanks"


DO YOU EVEN READ THE REPLIES YOU GET!

This has been suggested in 5 of the reply posts to you!!!!:mad: :mad: :mad:

I replaced my glowplugs and the timer last year and since then I the starts have been very rough and smokey. My injectors are new and I changed the plugs because four of them had stopped working. I'm going to try the extended glow time and see what happens it sounds like the fix to me.

Tried to search the post from ChrisK1500 you talk about but no luck can anyone help?

Here it is.:)

http://www.dieselplace.com/forum/showthread.php?t=129636&highlight=override

My 6.5 does the exact same thing as yours Lance. Did it with the original motor, and does it now with a new motor with a different inj. pump but the same injectors. Still does it with the new glow plugs (60G) installed in place of the original Bosch ones. So I'm thinking its leaky injectors on mine. I have a rebuilt set of Bosch here to install. I get about 30-40 seconds of white smoke after prolonged sitting (overnight or 5-6 hours) regardless of outside temps.

I will be installing rebuilt injectors(marine spec) this weekend. I'll post whether or not they helped on the cold start. I'm also taking the new 60Gs out and installing the Instant Heat set-up. Would like to do one at a time to see which, if any solve my little problem. I'll do both at the same time.

Fordguygonechev, my stumbling is only lasting 5-7 seconds. Yours is smoking white for 30-40 seconds. Maybe were not talking about the same problem. Thanks for the post. Good luck.

whats up...
When I had that problem it was a cracked head... 5 seconds of smoke and stumble then ran fine... I think I had 129,000 when it started...

Just a thought...

Johnny

Replaced the injectors, re-located the PMD(new PMD) and added the Instant Heat glow plugs. Truck never started or ran so good since I have had it. No more stumbling at start up. Next step is new exhaust, Health ECM and turbo master.

Good to hear its starting well. I just completed Chris' manual glow plug override. Haven't had the chance to try it yet on a cold start. I hope it starts somewhat like yours does now.

mine was doing the stumble for a few seconds when the temps had dropped, like you if i unplugged the temp sensor it was fine. well i lived without doing anything as the overnite temps started to warm up and the problem was solved. a few weeks back i did the remote pmd and just this week i expected the problem to happen again as we camped and woke up with 4 inches of snow. so i fired up the truck after sitting a good 24 hours. started great and ran fine and somehow the problem has not replicated itself. not sure what to do about it now. Ed