You're going to have issues with leaning out in the mid to higher RPM range with the 4.6 MAF. It registers less air than is coming in when coupled with a 4.0 ECU because of the increased housing size. I'd recommend picking up a 4.6 non-SAI ECU.

 

Thanks for the encouragement, Jacob! I am still waiting for parts after having paid overnight for several other to things

Alex, I didn't know was out the MAF issue. I've bought 4.6 MAFs and swapped the housings, so I probably have a 4.6 MAF now. For some reason I have found my off brand MAFs cheaper for 4.6 than 4.0. But I'm not SURE. I'm using your cold air intake mod...

 

Yea, I didn't know about it either until some of the recent ECU programming threads which pointed out the size difference. I think I included in the write up that the 4.0 MAF is smaller, but I better go double check.

That's odd. I don't think I've even seen any 4.6 specific aftermarket MAFs. I do know the 4.6 ECU doesn't play quite as well with aftermarket MAF sensors as the 4.0 ECU, which is strange.

 

I've lost track which MAF housing I am using and maybe which MAF element I am using. I am using my 4.0 ECU. . The 4.6 set I have is for SAI and I deleted SAI first thing. The 4.0 housing is smaller? I bet I am using the 4.6 because I remember using the biggest one for the cold air setup. If you recall I had misfires when I started up and I was pretty sure about the coil to plug wiring... I've since confirmed it was correct so I ordered new wires (wanted red ones anyway) and got champion plugs... Maybe I need to check that MAF and housing. I haven't had a chance to test it because I can't put coolant in it (waiting for part).

 

The element should be the same between the two, brand is the only difference, but if you used the size couplings I posted then you're definitely using the 4.6 housing. Maybe you could just unplug the MAF to see if that works. Even without coolant in it you can let it run for a few seconds, just not long.

 

Okay then I'm sure I have the 4.6 housing. I checked and I went with the biggest one for the Silicon hoses for my most excellent cold air intake. Sadly I'm in sin city at the moment so I'll have to try Monday. All parts should be in then anyway.

So the lesson is to use the 4.6 housing because the 4.6 needs more after and the 4.0 housingis smaller and constricts the intake of air.

Have you enclosed your filter?

 

Nope, I've left my filter wide open. I had cut up a Rubbermaid trash can and used some foam pipe insulation to make a kind of cold air box for it for a while, but it didn't really help a noticeable amount.

Just realized I'll be down your way week after next. I'll be flying into Houston for a week for a school conference. We'll be there for a week. Any recommendations for local food or sights?

 

I wish I could. I spend alot of time in Houston but I literally drive in to work and drive out. I just use yelp or go with a standby chain place. I never fail to find a Treebeards though for a huge plate a red beans, rice, sausage, onions, cheese, etc. Wow! Yum. Sleep for a week after that. Got me through school and beyond.

 

I am still vexed by misfires. 2, 6, and 7, with a p1300 and flashing SES for good measure. These are on different coils. New plugs (champion 322, gapped to .40), and new wires (Kingborne 8mm). The grounding strap is in place and tight. The misfires are real; it has a bad idle and the exhaust smells of gas (but no gas cloud like I had when the injector stuck). I am sensitive to the oil getting watered down, and it still seems fine (smells a little gassy but is viscous). Here is what I did:

checked all electrical connectors everywhere, top to bottom
pulled plugs on affected cylinders; they smell of gas and look like they are sparking
swapped plugs between cylinders and for plugs
changed MAF (I also ran it without the MAF for a few seconds to make sure a code popped up (1884, I think), and it did.
swapped wire for old one on #6 (easiest to reach on coil)

None of this made any difference. I reset the codes each time and ran it a short time until they popped up. What I did next:

started to pull intake and noticed passenger side injector harness ground (green wire) was OFF its mount at the bottom of the coil. Stopped intake pull, connected wire to battery negative with a jump wire, put bolts back in (I hadn't lifted the intake yet). THIS RESOLVED #6. But 2 and 7 were still a problem.

Took intake off. Checked condition of injector harness. While I had it off, swapped injectors on 2 and 7 for ones that I had already rebuilt (but not tested). Put intake back on. #2 RESOLVED.

BUT NOW I GET 4, 6, and 7! These are all on the same coil, but #1, which is also on that coil, is apparently NOT misfiring.

I should add that I stubbed off the throttle heater in the middle of all of this to avoid losing coolant when I removed the intake and just because it isn't necessary where I live. I just put bolts in the ends of the hoses and clamped them down.

Coolant looks good. Oil looks good. I don't have a single drip or any obvious contamination anywhere.

I checked all vac connections and even put duct tape on the connection at the front/passenger vac. line (with red retainer).... I have never trusted that thing.

What is this pointing to?

 

cylinders 4, 6& 7 are on the same coil as you said, stick an old spark plug in wires #'s 4,6& 7 and see if you have a spark when you ground it.