All,

I just got my truck back from my mechanic. After having the fuel filter replaced and completing a full tune-up, my rig still spits and sputters under load until it starts it warms up and then it seems to even out. Where is a good starting point to begin trying to figure out this issue?? I also have run some fuel system cleaner through a full tank with out any results to speak of. The only results came after the fuel filter was changed due to the old one being highly clogged.

Also, I was told my 5 speed manual tranny took ATF?? Does this sound correct?? I was under the assumption that the manual trans took gear lube. I have a 96 F150, 4.9, 5spd, 4x4.

Thanks in advance!!

 

If a mechanic wasn't just out for a quick buck & actually wanted to deal with the problem, He would have bothered to run error code scans. But you still can. See the sticky at the top of the page, or get one of these:
http://www.handsontools.com/Equus-In...ol_p_5574.html

 

And yes your transmission takes Dextron/Mercon III automatic transmission fluid.

 

Ok I will look ito the code reader. Are there any sensors that would and or could affect my rig? Also, I noticed this morning that the engine seems to be very under powered. When I was going up a mountain this morning, I had to keep it in 3rd gear and floored to maintain 50mph! The previous owner added a short ram intake, could this be messing up the MAF sensor? I am really at a loss here guys and need your help. What could be making it sputter when its cold and have a wicked loss of power all the way through the power band???

Thanks!

 

Error codes will tell you a lot. allowing you (us) to ID specifics, as well as rule others out. All part of the overall troubleshooting process.

To start w/, a compression test will tell you if your just getting what your engine's capable of. If your engine is only producing 100psi/cylinder or the cylinders psi are erratic some high, some low, Then you have a basic idea what it is or isn't capable of o begin w/.

o2's w/ over 60K will effect performance & mpg.
http://www.fordfuelinjection.com/?p=31
Cleaning the MAF sensor w/ electronic contact cleaner occasionally is a good idea. Disconnect it first.
http://www.fordfuelinjection.com/?p=26
Removing, cleaning, reinstalling & testing the IAC is a good idea too.
http://www.fordfuelinjection.com/?p=39
Removal cleaning the EGR is a good idea too.

A fuel pressure test is also a good idea.

I just noticed your 96'. If it's OBD2, you'll need an OBD2 code reader. The OBD1 unit I linked to won't work.

 

Ok that sounds like a good idea with the sensors. How would one go about cleaning those sensors appropriately?

 

The IAC is a solenoid valve, not a senor.
http://fullsizebronco.com/forum/show...&highlight=iac

Buy a Haynes Manual.

How many miles on the o2'?s?

You need error scan codes ran.

 

I am not familiar with the 4.9L but look towards simple stuff first. I don't know how complete the tune up was, but if it is a sharp spit and sputter check secondary ignition components. These are the components that generate and carry the high voltage to the spark plugs. You know, ignition coil, sprark plug wires, spark plugs, etc. Marginal secondary ignition components typically break down under load and when cold.

Good Luck,

 

That IAC cleaning site is great! I will for sure do that!
I have a Haynes Manual and I assume by you mentioning that I should look in there for cleaning techniques??
The truck has 123xxx miles on the original O2 sensors....should i replace them too??

If there is no check engine light so how will I get error codes??

Again, thank you all for your help!

 

My tune up consisted of new plugs, plug wires, cap and rotor button. I also used dielectric grease on all of thr components. How would one go aout checking the ignition coil??

Thanks!!