Another rough idle & hesitation question from newbie

[VolCTD]

OK, first here's the truck; 2003 2500 CTD 4x4 auto trans all stock with 87k miles.



I've read several other posts about folks rough idle on a cold start and I have a similar problem. It also wants to drop RPM's when I let off the pedal and it drops below 1000 RPM. It has died several times going down the road on me. It also has the hesitation problem from a dead stop. Sometimes the rough idle will come back after a long haul and you come off the interstate. But for the most part clears up after the truck is heated up really good. I've got to get this fixed as I just bought a 5th wheel and can't say I want to be driving down the road and it die on me every little bit.



I add PS to each tank as well as 2 stroke oil every other tank. I bought the truck used in July and they replaced the lift pump before I picked it up with the new "in tank" one for me. Since then it's been back and had 3 injectors replaced, the water pump (not related), and the cam sensor replaced. When they replaced the cam sensor everything cleared up for about 3 weeks and now it is all back again. I have checked all the wiring I thought might have been frayed but nothing so far.



The next thing I was going to try is a new FCA. Would this be the next best place to look?

 

[Johnstra]

Welcome to TDR, Vol.



You didn't mention hard starts so I'm assuming you don't have that problem? All the same, check your oil level to make sure you aren't making oil (leaking fuel into your oil).



Your fuel pressure is probably ok since you have a new lift pump. It would still be good to put a gauge on the input of the CP3 and see what your pressure is.



Another to check for is the 'bare wire problem' down near the A/C compressor. There's a wire that rubs against a bolt on the compressor on early 03s.



Good luck getting it sorted out.



Btw... fill in your signature with your truck details.



-john

 

[VolCTD]

Yeah, i don't have any hard start issues with it. As a matter of fact when it does die on me it fires right back up with no problem (unless it dies again on me!).



I checked out all the possible wiring shorts last weekend and found none. all my wires are covered in the plastic loom and all the tape looked good.



I'll double check the oil tonight, it's time to change it anyway so I may do that this weekend.



It's so intermittent that it drives me nuts. At least when the cam sensor went out it finally thru a code for it. What really baffles me is after they replaced it the truck ran perfect for almost a month and then started right back again. It is somewhat worse in cold weather but not much. To give you an example I started it Saturday morning and it died about 3 times in the driveway and then another while going down the street from my house. all day it would idle rough at lower RPM's and act like it was going to die when you come to a stop. It never died again during the day but sure didn't run good.



I plugged it in last night (only got down to 25 here) and it started and ran fine this morning all the way to work.



The engine is still under warranty but if they don't have a code they don't know what to fix at the dealership I bought it at. Plus it's a pain tking it out there and leaving it with them and then I still have to pay the $100 deductable.



Thanks for the help...

Welcome to TDR, Vol.



You didn't mention hard starts so I'm assuming you don't have that problem? All the same, check your oil level to make sure you aren't making oil (leaking fuel into your oil).



Your fuel pressure is probably ok since you have a new lift pump. It would still be good to put a gauge on the input of the CP3 and see what your pressure is.



Another to check for is the 'bare wire problem' down near the A/C compressor. There's a wire that rubs against a bolt on the compressor on early 03s.



Good luck getting it sorted out.



Btw... fill in your signature with your truck details.



-john

 

[Hoefler]

Which Power Service are you using, white or grey bottle? If not the grey bottle, use it, it is for injector cleaning. Mix it on the strong side for a couple of tanks.

 

[VolCTD]

I switched to the white bottle when it started getting cooler. I normally run the grey bottle though, about 16 oz. to a tank of diesel. How much would you say is on the "heavy" side to add?



I've also replaced the fuel filter back in Sept. or Oct. time frame. The one I pulled out was fairly clean, not a lot of crud anyway.

 

[Johnstra]

Yours doesn't sound like a fueling problem to me. Sounds more like it's electrical. Maybe a sensor. The new cam sensor could have crapped out on you. You also have a crank sensor mounted down by the harmonic balancer and there's the map sensor.



No codes, huh? Have you tried displaying codes? I don't remember how to do it.



-john

 

[VolCTD]

I tried displaying them by turning the iginition on & off 3 times. It then reads "done" and goes blank. When the cam sensor went out this is how I got the code for it.



Bill

 

[RichardMClain]

I have a 2004. 5 and had a rough idle on startk it was finally diagnosed and fixed by replacing 2 injectors. Hope it is still under warenty as it was expensive.



Richard

 

[VolCTD]

Richard---



The engine is still under warranty. They've already replace 3 injectors on it. I went out and talked to the Sales Manager about all the trouble with it since I drove it off the lot 6 months ago. He called back and wants me to bring it back out for them to start working on it again. He wants me to sit down with the Service Manager and go over everything again, at least they are trying to make it right. I told him I was just tired of making trips back and forth and it's not getting fixed.



I agree with John that it sounds like either computer or sensor related by the way it acts. I've looked for frayed wires but haven't found any yet.



Bill

 

[VolCTD]

Well it spent the day at the dealer last Friday and they went all over it and decided it was a clogged air filter. While I am leery as can be of this it hasn't acted up since then. I had a fairy new (4 month, 4000 miles) Fleetguard filter on it. They gave the old one and it was somewhat dirty but not what I would call terrible. If this is the problem and it only took that much to clog the filter and make the truck this bad I may need to look at upgrading the air intake system on my truck.

Bill

 

[Cattletrkr]

Has the new filter clogged yet? Sounds like a dealer solution...

 

[VolCTD]

So far so good. I'm still leary that a somewhat dirty filter caused this much of a problem. Aside from daily driving the only 2 major dirt causing drives I had in the last 4 months was a 1300 mile trip to Florida and about an hour drive on a very dusty gravel road.



I'm going to do a cold air intake to the air box this weekend and see if this aides in airfow to the turbo. I'm sure it won't hurt anyway.