Dads 03, again.

[6speedsd]

Been trying to diagnose a hard cold start and rough running on dads truck. Thinking ICP is part f the culprit bit haven't had a chance to tear it down and replace yet. Hooked a gauge up to test port on fuel pressure housing just now. Soon as you cut the key on it builds to 52lbs. Holds there through the long GP cycle, right up until fuel pump shuts off. Then it drops to 0 instantly. Key off, then back on, instantly to 52. Pump shuts off, instantly back to 0. I assume he either has a bad fuel leak on the rail somewhere, or his FPR is bad. What do y'all think before I start just making more assumptions?

 

[jdc753]

that fuel pressure drop sounds normal. On my truck if I wait longer than the light or whatever time period it is, my fuel pressure will drop to zero. Truck starts same as if the gauge is reading 50+ psi.

 

[6speedsd]

Just seems odd to me. On my 05, it holds pressure until I shut the key off.

 

[Pizza pig]

the stock fuel pump is on a relay for 30 seconds, it shuts off, so it stops sending pressurized fuel to the bowl. That is 100% normal. The pump on your 05 never shuts off, even after 30 or so seconds?

 

[6speedsd]

Not that I recall. But I could be wrong.

 

[6speedsd]

Ok, checked a few more things this morning. Truck didn't get plugged in last night an took forever to fire over. 2 long crank cycles before it fired. Noticed battery voltage dropped to 8.5v, so he obviously has a bad battery. That would explain the long cranks. Ficm voltages are all good though. I did check that. Did a buzz test before I cranked it and couldn't get #8 to click. He has thrown a cyl cont code for #6 several times, but never #8. Weird thing is that once the truck fires over it idles perfect. No smoke no surging. But it will sputter when going down the road for a while. If injector was bad shouldn't it idle rough until it warmed up?

 

[Atsah]

First things first.. Fix your battery problem then troubleshoot.. Not enough juice to the FICM will cause problems, troubleshooting a cold start issue with insufficient battery voltage is a waste of time..

 

[6speedsd]

Oh I'm sure that's what is causing his cold start issue. I'm just wondering about the injector.

Here's another thing. Is the voltage regulator replaceable by itself, or do you have to get the whole alternator? He had a voltage too high code this morning, and when he gets on the truck, it shoots up to 15v. Lights on the cluster flash and needles pegs out. Sounds like a faulty regulator, but want sure if we could just replace that without a whole new alternator.

 

[Atsah]

If you have a bad diode in the alternator itself, it'll freak out the regulator and sometimes cause it to peak like you're seeing.. I recommend replacing the alternator..

 

[6speedsd]

Ok, answer this for me. When I'm doing a buzz test, if say #5 didn't buzz, would there be a definite pause between 4 and 6 during the sequence? Or would I just hear 7 sequential clicks?

 

[6speedsd]

Played around with I some more this morning. Didn't want to fire at all. Long cranks and it would finally hit but was getting white smoke out of the exhaust. Hit over 3 or 4 times then finally cranked. Huge cloud of white smoke when it did.

ICP still reading 30psi KOEO. While cranking shot up to 2000, then running reads just under 1100.

IPR about 30% at idle.
ICP voltage at idle around 1v.

Ficm info for sync is yes when running

CMP and CKP in sync...flashes from yes to no at idle. We replaced CKP about a month ago

CMP level says low at idle, but shows no fault.

Ficm logic and vehie power show 14v at idle. So does battery voltage. Both batteries pass load test.

Fuel pulse around 950 uSec.

Anything stand out here? I read somewhere about white smoke on a long crank but don't remember what it was about.

 

[F-250-Owner]

sounds like the gpcm might be going.....

 

[6speedsd]

Just went and had batteries load tested again. I wasn't too confident in the guy he let do it last week. Sure enough, one is bad. Soon as you put a load on it, it falls on its face. Will get that replaced this weekend an see how she acts then.

 

[Mdub707]

Figures, that's a good place to start though. You're really supposed to replace both now, but that's your call. Get the new batts and let us know how it goes after this, you'll be amazed how different they run/start with good batteries.

 

[6speedsd]

Oh I know. He's out of town through the weekend so it'll be Monday before anything gets done to it. Still wondering about the miss it has though. Idles perfect but going down the road in OD it'll miss hard. Get on it some and it clears up. All 8 injectors passed buzz test. Though that might be an issue at first but who knows.

 

[Mdub707]

Stiction... batteries may help overcome that some as well.

 

[6speedsd]

I thought that at first, but this thing idles smooth as butter on a cold start. I mean like its already up to op temps. If there was stiction I'd think it would run worse than that until it warms up. It has to run close to an hour before that miss clears up, but the miss is only while going down the road, like I said in OD.

 

[Mdub707]

Nope, that's how mine has always been with stiction, starts and idles fine, but if you take off once it gets up into overdrive it starts missing. Once warm, it disappears. Have you tried some rev-x or archoil in that thing? Worth a shot, if you add it in and it disappears, there's your problem.

 

[6speedsd]

I've been trying to get him to go buy some Revex but he says he keeps forgetting. We stay busy year round. I have to make him plan us a day with nothing else to do so I can do maintenance on equipment. Before I started working for him, maintenance never got done. That's why his truck is in the shape that's its in now.

 

[Mdub707]

Just order some from a site sponsor, not many local places will have it.