Spits, Sputters, falls on face once warmed up

[98Z]

I have a '98 5.7 that become a HUGE money pit.

The ONLY code that it's throwing is the P1153 for the O2 sensor, but that code was popping up long before this issue started.

Currently the truck will start acting up, almost sounds like it's misfiring. But it only happens after it reaches operating temp... usually about 10 minutes after I leave the house (from dead cold). This wouldn't be a big deal if I were ONLY driving it to and from work, but this is also a plow truck, so I kinda need it to run.

The engine was a complete rebuild 15,000 miles ago. Just about anything that could be new on this truck is new. I've spent a ton of money making it a reliable daily driver, but it keeps wanting more... like that damn plant on Little Shop of Horrors!

The injection spider was updated with the new setup. The fuel tank is new, the sending unit and pump are new, the filter is new. I just replaced the coil and had the module tested. Very recent cap, rotor, plugs and wires. Distributor is even fairly new. No, not all of this was done attempting to track down this new issue, just listing all the new things I've dumped into this truck over the past couple years. It's almost a new truck, except that it's kinda rusty in the rockers and cab corners.

Anyway, it's been suggested that the fuel pump may be the culprit .... AGAIN! (I've changed it 3 times already!!) I believe that when the pressure was tested last week, it was below 50 psi. But, like I said, this isn't a constant issue, just after it's gotten up to temp.

I'm kind of at a loss and really tired of throwing money at this damn thing. Snow is coming and I need to get this thing right, not to mention the fact that it's the only transportation I have (suitable for winter).

Any thoughts or suggestions would be much appreciated.

[777stickman]

Maybe I missed it, but, what have you done to correct the P1153 code?

[98Z]

Originally Posted by 777stickman

Maybe I missed it, but, what have you done to correct the P1153 code?

Nothing as of yet, but I do have the new O2 sensor. However, the code has been popping up for quite a while with no issues like this before. I hope to get the O2 sensor replaced tomorrow, but I don't know that it will have any affect. I can hope.

[Schurkey]

First Guess: Everything you need to know to fix the problem is in the data stream.

You need a scan tool. (Not a "code reader".)

[98Z]

Originally Posted by Schurkey

First Guess: Everything you need to know to fix the problem is in the data stream.

You need a scan tool. (Not a "code reader".)

So I should take it to a mechanic, right?

Umm, the whole point of me asking here was to avoid taking it to a mechanic and spending a small fortune.

I have a scan tool, but the data stream information doesn't do me much good if I don't know what I should be looking for.

[Schurkey]

Originally Posted by 98Z

So I should take it to a mechanic, right?

If that's what it takes...yes.

Originally Posted by 98Z

Umm, the whole point of me asking here was to avoid taking it to a mechanic and spending a small fortune.

And yet you can replace parts at random, without complaint.

Originally Posted by 98Z

I have a scan tool, but the data stream information doesn't do me much good if I don't know what I should be looking for.

What is the O2 voltage when it's acting up? Rich, or lean, or swinging back and forth?
What is the coolant temperature when it's acting up? Unusually hot--unusually cold? Is the coolant temp as displayed believable?
What is the fuel trim (both short- and long-term) when it's acting up? Rich command, lean command, or near the middle?
Is there knock-sensor activity when it's acting up?
What is the engine vacuum level when it's acting up? Low vacuum? High vacuum? Is the vacuum any different than when it's running good?
What does the data stream tell you about misfire? No misfire? One cylinder misfire? Random misfire?

LOOK at the data stream. There's got to be something there that looks goofy when it runs bad, that doesn't look goofy when it's running good.

[rhandwor]

Below 50 psi is to low for this engine. Have you ever checked the fuel pressure regulator.