Injector Maybe? But how...

Nic · Jul 23, 2013

The truck has 156k. Stock sticks. I keep up with the oil and fuel like no tomorrow. THe truck is a grocery getter. Drives on the weekends. Im not throwing any codes, she starts up just fine, no shaking, shimmy, rough idle, no white smoke, no nothing. I ALWAYS let it warm up to at least 120 before it leaves the drive. Here lately, right when I take off, just moderate throttle getting up to speed it sputters like a bad injector. Not bad, but you can tell. I have no idea how one could be bad. I run amsoil with the bypass kit and still change it every 5-7k. I get fuel from one place only and it sees either the ford additive or stanadyne EVERY time. The only other thing I can think of is fuel pressure maybe? I have the AD100 and its working fine, and I know Its just a pusher pump, but could I still have a FP issue that could be causing this?

Ill be putting it on a graph soon, but thought I would still ask in case I was missing something. It seems a little more sluggish than it used to be but the transmission is pretty much shot also.

nchappy · Jul 23, 2013

does the sputter go away after a few miles?

HOOV3R · Jul 23, 2013

FICM voltage?

Nic · Jul 24, 2013

Yes it goes away after awile. And it only does it when i start making it fuel pretty hard

Nic · Jul 24, 2013

I havent changed the factory filters in quite awile but the AD filters should keep those pretty clean...It sputters just like a bad injector, but you would think that if it was, on a cold start there should be a hard start, rough idle or something along those lines and theres nothing. She purrs smooth.

Lassie · Jul 24, 2013

Make sure batt V and alternator are good first! A bad batt cell can hurt performance in these until alt gets it charged up. Then test FICM (all three cond), then fuel pressure. If you make it through all of these, contribution test and power balance inj.

nchappy · Jul 24, 2013

Get some rev-x and see what happens. Can only help and takes no time at all.
I had a recent stiction issue that caused 2 injectors to studder under acceleration. Problem went away when engine got warm. Rev-x solved it, for now...

Mdub707 · Jul 24, 2013

Lassie said:
Make sure batt V and alternator are good first! A bad batt cell can hurt performance in these until alt gets it charged up. Then test FICM (all three cond), then fuel pressure. If you make it through all of these, contribution test and power balance inj.

Do this.

Does it go away when it warms up completely?

Just because you're on top of your maintenance doesn't mean all 8 injectors will last forever, you're just ensuring you'll get max life out of them. They will still fail at some point. You're talking about a VERY tight tolerance machined part, that is bolted into the head of a combustion chamber in very high temps. It's believable that it would fail at some point.

Cold Roller · Jul 25, 2013

It sputters just like a bad injector, but you would think that if it was, on a cold start there should be a hard start, rough idle or something along those lines and theres nothing. She purrs smooth.

It doesn't always work like that. Often one injector sticking will start fine, but show under early acceleration. It usually takes 2 weak injectors to make a hard start. Of course as suggested, look at the FICM, but further, ensure your AD is not eating itself!