It makes perfect sense that it would drive fine with it unplugged. With the MAF sensor unplugged, the PCM defaults to a speed-density table for fuel & spark control rather than a mass flow table. When in the speed-density table, the MAP sensor is used for determining engine intake air conditions rather than the MAF sensor. The MAF sensor is more precise for more efficient control which is why it is used, but needs to have all of the air entering the engine passing through the sensor for it to work properly. Given that you have a known problem with the seal at the top of the throttle body and likely a vacuum leak at the bottom of the throttle body due missing one of the three retaining bolts, that right there is more than enough to cause misfires.

 

Yes. I'm not ignoring what you say. I need to take some time and take a good look at the top and see why those things are missing.. I was able to locate a screw that is holding it on, however, there are still things missing. And aside from replacing the whole thing (the whole hat and tube) with some kind of other system ? (Aftermarket, CAI.. Still comes back to that hat, unless the kit includes it and a screw...) then that may be pointless since, as swartlkk said, anything 96-04 and in a yard will work.

I really need to locate that screw. For whatever reason, it was not on the old engine.

After I get that licked, if for whatever reason the issue remains, I would then look at other things. I could also spray the MAF with the dedicated CRC MAF cleaner, as I did again, today.

 

I will try to source the appropriate stud/screw as the first thing, yes, but let me just ask.. Has anyone had success with these other full intakes?

I am clear that that is the likely cause and maybe yes maybe I will locate a yard . I may even know of one.

https://www.ebay.com/itm/K-N-57-SERI...YAAOSwXSZeRc~d

 

Cylinder #2 seems to be setting the Misfire code..it is intermittent, and sometimes runs fine.

Spraying butterfly valve (under the hat) with carb cleaner makes it MUCH smoother. No longer surges or stalled at light with standard MAF plugged in...

May have to either custom make OR find a new screw, on new "hat." I have to find a yard near me. If there are any studs for that wing nut left..

As of tonight, I get to take it to work. Sometimes, the light is flashing, but the truck feels like it is running fine..I am not sure why that is. It does not flash all the time.

 

^ Update: ~2PM 4/3 (see what I did there) 2020..

FIXED. (The misfire)

... Spark plug wire #2 was LOOSE and far enough out to basically be OFF.

Clicked it back on.. GREAT SUCCESS!!

Now to drive it to work tonight.

Surge is almost nonexistent now, everything plugged in...

 

Sounds like you're getting it worked out.

 

Here is my old air filter. I was not sure if it was dirty or possibly causing all my problems or not (dirty air filter..) so, as a precautionary measure, I replaced it.

I am soon to have my choice about either sticking with this one.. or using a K&N "FIPK 57" or something like that oil-able one. That is all secondary.. and found during my quest to either 1. Get a screw and new hat, go OEM or.. 2. If #1 is not possible, go another way to make sure hat fits secure and cure the vacuum leak, which everyone seems to see except for myself.

As stated previously.. I get it. And I do not want to frustrate anyone.. Only part out of the Parts Cannin fired so far has been the air filter and possibly intake setup, here is the old filter and of course the new one is brand new.

(and no, if anyone was wondering, I am not trying to "I just wanna go fast! Yeah! K&N! Burn rubber! WOOO!" NO... This is simply in furtherance of No more vacuum leak at the hat, and I am happy.)

When I got the engine back, after $1440 Labor for an engine change, the intake was laying in two pieces on top of the engine and stalled out a mile down the road, had to leave it overnight as I had to go to work, opened up the hood and said.. "Oh." So. That's where i am coming from, so. The fact I got it to run perfectly at all has me super happy, now every erratic idle and sound has me anxious.. heh. But it does run perfect.

Almost there..

 

Here is the latest on how she sounds.


The new "hat" is coming any day soon now. (By Saturday)

 

Note on the hat, once the new one comes in you need to redo how you have the entire assembly bolted in, to me it looks like you bolted the air cleaner stud over the hat and then the hat retainer stud ontop of that. this is how it should be - and please make sure you check torque specs on all the upper intake studs and the throttle body, should be 44 INCH lbs and then 80 INCH lbs in a cross pattern. at minimum check that rear throttle body stud.

 

^ Yup, an pretty clear on how it should look and be mounted now. Only took about a month, but I see it now. After becoming intricately aware of that screw, and how it should mount.

So, seems like my "hat" is indeed broken three ways:
1. The circle is now open on one side, where the hat attaches to the screw. (I did that. Before I knew how key this was. The whole engine.. one screw. Crazy.)
2. The mounting bracket on the front is not there.
3. The orange seal seems to be gone, and though I can no longer move the hat by hand, it still is probably not sealed .

Tom A and swartlkk called it a long time ago. Is swartlkk still silent in protest?

Sooo... today, we switched the screw and mounted it with a 13mm nut instead of that black plastic contraption. The result is, that, while the new intake hats are on their way, one from K&N one from Spectre and I'll likely return the Spectre (hat) and keep the K&N (my choice of all components.. maybe air filter and hat.. maybe just hat.. not sure) since I did not want to chance it on factory used units with possible bad seals... at least to start.. and they should be here on or by Saturday.. the truck is almost completely smoothed out and seems to be back to running fine, once ththe vacuum leak is completely licked.

Somehow, I bought it with the brakes leaking air badly, and only with a very high idle can I get it to not surge at light so.. That is the next thing to be looked at, too.

Pic coming up. Yes, the hat will be changed I am more mad about the kid that ran into the side of my truck than the actual engine now lol. Those doors. Must. Be. Fixed. Or replaced. Whatever makes it look like nothing happened...