rough start up

[MattM]

This has just begun happening when I start my truck. After my truck sits overnight, about every 5th time when I start the engine it idles rough. It sounds like there is a radical high lift cam in the engine, idles rough, then smooths out after about 10 seconds of this rough idle.

Any ideas why this is happening? Temperature does not seem to matter.

Signature with mods.

 

[Tail_Gunner]

Sounds like the infamous morning romping idle to me.

If thats the case, it's an issue with high pressure oil going to the fuel injectors, and a pressure imbalance between the right side & the left side. Ford says it's a characteristic of the motor when cold started. Their fix is to plug the block heater or switch to a lighter weight oil.

What worked for me was a HPX mod where you install a high pressure cross-over tube between the two cylinder heads.

I have tried several versions of the HPX mod, a Steel Braided Hose style, a Hydraulic Hose style, and a Solid Stainless formed tube style.

Of the three, only the solid tube type has lasted longer than 18 months for me without begining to leak, usually at the crimps where the fittings attach to the hose.

A couple of extra side effects of the HPX mod (the actual amount of benefit has been debateable from person to person) is a smoother idle and a quieter idle.

But I can say with 100% certainty that I haven't had any problems with the morning startup loping since, no matter whether it's plugged in or weight of oil in the crankcase.

 

[MattM]

It is a "romp". I installed the high pressore oil crossover about 5 weeks ago. Used the high pressure rubberized hose similar to the one from Diesel Innovations. Never had the "romp" before the installation. The "romp" only started within the last 2 weeks.

Something else happening???

 

[professor]

Rough Starts

Hi All,
I'm a "newbie" here (first post) and could sure use some of your collective knowledge/experience.

I'm having the same (I think) problem as MattM. I, however have not installed any high pressure lines.

Truck: 2003 7.3 F350 (115,000 miles).

I've owned the truck for about 4+ years. Live in NW Florida (mild winters). Have had the truck (last year) in much colder climate (Chicago winter) and no problems. The last 3 mornings (low 50's temp.) the truck was difficult to start. It seemed to "lope/buck/romp", appeared to be "missing". After 3-4 starting attempts, once I got it started and gave it a little "pedal", it seemed to smooth out. The rest of the day - no problems.

Glow plugs, injectors??????

Any advice/help would be much appreciated.

Thanks,
Professor

 

[BJS]

Hi All,
I'm a "newbie" here (first post) and could sure use some of your collective knowledge/experience.

I'm having the same (I think) problem as MattM. I, however have not installed any high pressure lines.

Truck: 2003 7.3 F350 (115,000 miles).

I've owned the truck for about 4+ years. Live in NW Florida (mild winters). Have had the truck (last year) in much colder climate (Chicago winter) and no problems. The last 3 mornings (low 50's temp.) the truck was difficult to start. It seemed to "lope/buck/romp", appeared to be "missing". After 3-4 starting attempts, once I got it started and gave it a little "pedal", it seemed to smooth out. The rest of the day - no problems.

Glow plugs, injectors??????

Any advice/help would be much appreciated.

Thanks,
Professor

Professor welcome to the site I would guess that your problem is glow plug related and quite likely the relay Here is a post where I've gone through the information on how to diagnose the glow plugs & relay

Another easy diagnosis technique for you is to plug the truck in for about 2-3 hours before you try to start it and see if it is easier to start.

 

[professor]

Starting Procedure

Brandon: thanks for your quick reply (thread and PM).

This morning I tried to start the truck a little differently. Turn key on, waited till GP symbol went out, pushed the pedal down some, and then turned key to engage starter. It started right up, but if I let off the pedal it wanted to run rough (lope/romp) - if I pushed the pedal some, it smoothed right out.

If this was a carburated vehicle, I'd set the idle up some and/or auto. choke. Is there anything similar on the 2003 7.3 PSD or is this a sympton of a problem I need to look into?

Thanks,
Professor

 

[BJS]

nope nothing to up the idle on a stock PSD. you do have 2 options

1. AIC - Auxillary Idle Controller
2. Chip with high idle programmed.

Professor I think you have a GP issue on some level, if you let the GP light go out in these temps you should not have a romp at idle with a functioning gp system.