Hesitation under acceleration

[jamesj]

Hey everyone, Im new to this forum and first off let me say that this forum is great. The forum has already helped me to fix my 4x4

I recently purchased a 91 xlt. I got the truck for the occasional weekend outing or to tow around the boat.

The truck was running a bit rough when I bought it so I did a partial tune up including plugs, air filter, oil and filter, injector cleaner.

After the tune up the engine runs great and rev's at the correct rpm it sounds great, I can let it run for quite some time and all is well.

The problem is that when I am driving (after the engine warms up) the engine begins to hesitate under acceration especially on hills

I have read about this type of problem and generally the solution is either
cleaning the maf sensor, replacing the fuel filter or the fuel preasure regulator

Before I spend the money I just wanted to ask if anyone has experinced similar problems and perhaps the solutions

thank you Jon

 

[Anime]

Cleaning the MAF sensor, and cleaning it well, makes a good bit of difference, especially if it's never been done, and will only cost you the can of air intake cleaner, which you can get a lot of use out of.

Removing the MAF housing from the intake tube and cleaning inside it can be beneficial as well, there is a screen inside there that tends to get a little dirty, and cleaning it seems to make some difference. While you're there, inspect the plastic intake tube for holes, cracks, and other openings, especially around the flexy areas. Seal up any you find with black silicone or some similar good high temp sealant.

The spark plug wires make a fair bit of difference, so if they look old or are possibly even the original ones, new ones are a good idea.


Stuff like replacing the fuel filter is also a good idea, especially on a ride you just bought.

 

[fixxxer]

While your under the hood, clean the IAC valve too, especially if you are having any kind of idle issues and maybe check your IAT and CTS, it only takes like 5 minutes to test the IAT sensor and coolant temp sensor.

 

[jamesj]

So how does one clean the maf sensor? Im sure there is a thread that would describe the procedure?

 

[ranger7ltr]

I would look at the fuel filter as well...

Since I bought my 99 Sport I have had to clean out the tank thanks to varnish from old fuel, dirt, etc...The truck had been running well for a couple of months until yesterday under hard acceleration...I was thinking maybe I was low on fuel after a 200 mile road trip but I could only put in 8 gallons so lack of fuel was not the problem...

Plus watching the fuel pressure gauge showed that the fuel pressure was indeed dropping...Changed the filter this morning and it was definitely full of crap and plugged up...

So new filter in and engine performance is back to normal...