Camshaft Position Sensor/Synchro complications - Please help

[425Exploder]

Hi guys,
New to posting. I have a problem with my 96 4.0 4x4. I bought the truck about five months ago (Best thing I've ever done). And noticed that the fuel economy was pretty poor at 10mpg. So I did a full tune up; Plugs, Wires, Air filter, Fuel filter. This helped slightly, 12mpg, but it still lacked the mpg's and definitely power.
Did a little research here on this forum and found that the Camshaft Position Sensor & Synchronizer are commonly faulty in these trucks. So I bought the whole assembly from one of the local parts stores because it only cost me about $200 for the whole thing, rather than $500 from the dealership.
I then took my truck to the dealership because not many shops in my area knew anything about this and was going to charge me roughly the same, or even more than the dealership. So I took the truck to the dealership feeling confident that they knew what they were doing.
Boy was I wrong. The service clerk called to inform me that the mechanic didn't have the right tools for the job, and that they needed more time. I thought to myself "Ok, things like this happen."

I then pick up my truck and it now has the check engine light is on. Mind you, I dropped it off with no codes. Now the truck has three codes; PO303, PO304, and PO171. Which leads me to think that in replacing this part, the mechanic didn't reassemble the intake properly.

Does anyone have any ideas or places to start looking at?
Thanks for your help,
Troy

 

[rb142]

So take it back to the dealer.

There is no reason to mess with the intake to change a cam sensor and synchronizer. Those codes (misfire and lean) shouldn't be related to the synchronizer unless the mechanic did something else while in there. You can start by checking the really simple things, that the intake air tube is connected properly (not cracked), and there aren't any vacuum lines knocked off. Symptoms suggest you have an air leak somewhere.

The CAM sensor and synchronizer aren't going to have any impact on fuel economy at all, and a number of the cheap aftermarket parts are known to cause problems. Changing that was probably a bad move. When the synchronizer fails, you instantly lose oil pressure and can kill the engine if you don't stop it fast enough.

 

[SensRanger]

In my experience, the synchronizer will make a squeaking sound when it's worn. Almost like a belt squeak, mine became nearly as loud as an emergency siren. On the 3.0L, apparently replacing the synchronizer is a breeze as it's easily accessible. On the 4.0L you and I have, changing this part does require removal of both the upper and lower intake to gain access. So it's possible the dealer didn't put it back together properly, or re-used old gaskets. (Did they charge you for a gasket set?) I put a Dorman synchro in, then saw the horror stories later. So far, no problems. Most of the horror stories seem to date from about 2010-11, so hopefully Dorman updated their part to address the concern. Good luck.

 

[425Exploder]

The dealership did call and asked about the intake gaskets. I told them to use new gaskets and they did charge me for them.

 

[pcam13]

Use a vac gauge, the one I have indicates late timing and or an intake leak