Could use some advice.

[dustinjorge]

Could use some advice (surging/sputtering) warm start.

OK, the long and short of it is this... I've got the intermittent surging idle on warm start issue. It's random, only seems to happen this time of year and definitely only after the truck has been going for a while (Usually after a few minutes on the freeway).

Been chasing this issue for years, it seems to come and go (I haven't noticed it for quite some time, but recently it's been acting up again after my most recent tune up.) I've seen a lot of threads with similar problems, and have tried most of the solutions that just aren't solving my problem.


Symptoms:

1. Park the car after warming up. 10-45 minutes later start the truck. RPMs up to about 1100 then down to 4-500 and and continues to 'surge' violently up and down for anywhere from 10-20 seconds then up to about 1200 for 2-3 seconds, then drops down to 700 where it smooths out.
2. No Codes.
3. Once in a very long while, it'll sputter/shake a bit after coming off the gas.
4. Smells like it's running rich often (Cat smell)
5. Idle has light bumps (I want it perfect)
6. Bottom end noise, sounds like an exhaust leak/gurgling, gurgling sounds like it's coming from oil pan since I put castrol in it, could be unrelated?
7. No Stalling
8. Starts fine cold
9. Otherwise, runs like a champ

What I've done recently (past few weeks):

1. Cleaned IAC (1yr old motorcraft)
2. Cleaned MAF (3yr old aftermarket)
3. Replace Air Charge Temp Sensor (Aftermarket, NAPA)
4. Clean + light oil K&N
5. Oil Castrol GTX 5w30
6. Motorcraft oil Filter
7. New motorcraft plugs
8. New motorcraft wires
9. New motorcraft DPFE
10. new EGR vacuum hoses (plastic ones) from pick and pull (good shape)
11. Had cats checked for flow (Midas)
12. Had Exhaust checked for leaks (Midas)
13. Thermostat (motorcraft, prev started sticking)
14. Instrument temp sender (motorcraft)
15. Visually inspect vacuum lines (Prob could spend more time on this)
16. FPR (Napa)
17. PCV

Also Related:

1. O2 sensors (3 yrs)
2. Engine coolant temp sender replaced 3-4 years ago (Not sure if aftermarket, probably)
   IIRC I wrapped this in thread seal tape before installing, can this screw up the readings?​

Still on the short list:

1. Check Manifold bolt torque
2. Replace ECT again (Motorcraft)
3. Check for vacuum stability
4. Fuel filter (Been a while)
5. Fuel pressure
6. Revisit MAF

Anybody have any ideas? Am I on the right track because I feel like I'm chasing a ghost with this problem. I'd like to get some time in under the hood this weekend, what would you suggest I start with?

Edit:: I posted in the wrong section, hope someone moves it for me

Edit2:: I started another thread for the noise problem, I don't know if the two are related or not: http://www.explorerforum.com/forums/showthread.php?t=380926

 

[swshawaii]

Very surprised no mention of checking the commonly failed OHV intake gaskets and manifold studs for torque.

 

[dustinjorge]

Very surprised no mention of checking the commonly failed OHV intake gaskets and manifold studs for torque.

Thanks for the tip, I'll add this to the list this weekend.

 

[dustinjorge]

Well this weekend I replaced the PCV valve and the FPR... it's running great.

Still getting some serious noise from the oil pan right after an oil change.

Anyone know if the 98-00 TSB "Marble noise" is also applicable to older OHVs?

 

[dustinjorge]

Well, just got the sputter again after a warm start. I'm at a loss...

 

[1996BLKBauer]

Well this weekend I replaced the PCV valve and the FPR... it's running great.

Still getting some serious noise from the oil pan right after an oil change.

Anyone know if the 98-00 TSB "Marble noise" is also applicable to older OHVs?

I have this EXACT issue with my '96 V8. It scared the heck out of me the first time, but the truck ran fine, and had oil, so I could see nothing wrong. After a short drive it just goes away. :scratch:

 

[dustinjorge]

I have this EXACT issue with my '96 V8. It scared the heck out of me the first time, but the truck ran fine, and had oil, so I could see nothing wrong. After a short drive it just goes away. :scratch:

Mine's still there, not sure what is making so much racket, but I'm fairly certain it's internal. I posted vids/sound clips in the thread below because I'm getting off track about the random warm start/sputter issue that this thread is addressing.

http://www.explorerforum.com/forums/showthread.php?t=380926

The question is, what needs replacing ( and what's it gonna cost me :/ )

 

[1996BLKBauer]

Mine's still there, not sure what is making so much racket, but I'm fairly certain it's internal. I posted vids/sound clips in the thread below because I'm getting off track about the random warm start/sputter issue that this thread is addressing.

http://www.explorerforum.com/forums/showthread.php?t=380926

The question is, what needs replacing ( and what's it gonna cost me :/ )

I am not entirely sure about the sputter that you have, but I am just going to drive mine until it finally breaks, and just rebuild the engine. Like I said if it runs fine, there really is no issue, I know your case is different. Plus I have always been told by my dad, "if it ain't broken, don't fix it".

 

[dustinjorge]

I am not entirely sure about the sputter that you have, but I am just going to drive mine until it finally breaks, and just rebuild the engine. Like I said if it runs fine, there really is no issue, I know your case is different. Plus I have always been told by my dad, "if it ain't broken, don't fix it".

I found the cause of that noise. In my case it was ignition related. Check out that other thread I posted what I did.

Still not sure if the sputtering that this thread is addressing has been overcome. I'm fairly certain at this point it's a fuel issue. I'm going to keep chasing it.

 

[1996BLKBauer]

I found the cause of that noise. In my case it was ignition related. Check out that other thread I posted what I did.

Still not sure if the sputtering that this thread is addressing has been overcome. I'm fairly certain at this point it's a fuel issue. I'm going to keep chasing it.

Thanks man, I'll take a look, good luck on you search for answers.

 

[dustinjorge]

Well, just an update. The warm start sputtering happened again last week, so I dug in some more this weekend:

1. Changed ECTS with new one from ford (had to solder in new pigtail)
2. Changed fuel filter

I guess time will tell? :scratch:

 

[nolimitssjca]

You have a great list here. Did you ever sort this out?