So my truck has started romping like its only firing on 5 or 6 cylinders during cold starts. While romping, black puffs of smoke can be seen coming out of the tailpipe. Is this GPs or injectors causing this? When I flip the truck to the high idle setting on my chip the romp goes away. Thanks for any input guys.

Truck Info:
2000 F350 4x4 Auto 178,500 Miles
Rotella T 15W40 Oil (About 3500 miles on oil.)
Motorcraft Fuel Filter (About 14,000 miles on it.)
PHP 6-Position Chip
DIY 6637 Induction
Walker Muffler
Stewart Warner Gauges

 

Does the romp completely disappear, or does the truck just shake less in high idle?

The last two links in my signature may be of use.

 

The romp stops immediately, as soon as I flip the switch. I have tried starting in multiple switch positions (except high idle) with the same result. It has died once or twice while romping, this was before i realized the high idle makes it stop. The high idle is set @ 1000 rpm if that matters. Truck cranks and fires quickly, just goes to romping. Does anyone think I am hurting anything by switching to high idle this quickly after starting?

Thanks for the response and links Tugly.

 

Forgot to mention the truck has 178,500 miles on it. I have owned it for 3 years and do not know the GP or injector history.

 

does it do it all the time or only when cold??? If only when cold, I would try rotella T6 syn iol..

 

Although T6 would prob help.....there is still a problem. I would start by testing the glow plug system.

 

Only when cold. It only started doing this towards the end of last winter and obviously this winter. Never an issue before then, always ran the same oil. Is this a sign of aging fuel injectors? Really don't want to add $30 to my oil change price if I don't have to. Thanks for the reply.

 

Would it help if I took a video of the cold start and posted it? I can do one in the morning if anyone thinks it will help.

 

I think I have some GP testing how-to's saved somewhere, I'll take a look and see if I can do them tomorrow. I recently picked up a ScanGuage II, is there anything it can do to help me diagnose this issue?

 

I just went through hard starts and harder romps. It took me a while to cure them. Finally had to change injector o-rings. I hope your issue is easier to cure than mine.

 

Prob wouldn't help. There are several things it could be. Don't know anything about scan gauge. Start with glow plug system.

 

This is where I started
https://www.ford-trucks.com/forums/1...g-testing.html

 

After you've learned how to access the different parameters in the Scangauge, the troubleshooting tips in those links I've pointed out will be a huge help.

 

Go with the oil change to t-6 or even a 10/30 for the colder weather season. Worked for me and price is right!

 

Update on this. My GPs show 1.1 to 1.5 OHMs accross the board. Relay appears to be working correctly, only a minimal drop in voltage. Do you guys think it could be my injectors?