John van de Pol

I say "possibly", because it's only been two weeks, and I am not sure that it will last. But the car feels like it has received a steroid injection, and has not hesitated once since these repairs.
One potentially big caveat: The Monday I first took it out, fall hit here in Houston, and the temperatures dropped 15 degrees.

I also can't claim THIS is what did it, becase I did a number of things at one go, but here is a list what I have done.

1. Removed the throttle body, and cleaned out all the tarry deposits around the area where the throttle plate closes. Blew through all the passages. Used Throttle body cleaner and brake cleaner.

2. Spent over an hour removing old gasket from the intake plenum (what a pain)

3. Replaced the vacuum and purge hoses running from the vapor canister to the throttle body, and the two short ones connecting below the TB.

4. Replaced the air filter. (I just checked as I type this), it had only eight months an 4500 miles on it but it was dirty, and the dirt "showed" from the clean side of the filter.

5. Went 2 week-days with car apart because the Fel-Pro gasket spec'd for my engine did not even come close to fitting. Ended up with an oem gasket (local dealer, no discount, 7 some odd bucks) p/n 16175-53J00.
Also got a Fel-Pro for a Pathfinder (p/n 60853). This one fits the bolt pattern, but the tb opening is slightly too small. Easily enlarged with an exacto knife. Used the Fel-pro, saved teh oem for when I clean the intake plenum.

As a side note, the oem gasket does not appear to have an adhesive on one side or look like it is a sticker. So, when used as is, it should not be a similar nightmare to remove next time around.

6. Put DeOxit 5 (red) 100% solution on all electrical contacts for the TB position sensor, the TB hard close sensor. This is an electronics cleaner that de-oxidizes contacts, and lubes them to prevent future oxidation. You can get it at MCM electronics or Parts-Express. I have to say that all contacts of the TB sensors looked factory new.

So which part actually fixed the problem? I am not sure. When I tested the vacuum line from the canister to the TB, I heard a fairly significant hiss. That hose and the purge hose run through a protective sleeve, so you could not really take a good look at them. When I disconnected it, and capped the vacuum port, it did not fix the problem, so I have my doubts there. I have, however, suspected a vacuum leak for a long time, but could never find an obvious one. The TB gasket could have leaked. Again, unlikely, because it was tight (4 bolts were pretty frozen, and the gasket looked ok visually. But having done all this, the Max got its spirit back. It had been gone for a long time. I may have better mileage, but I won't be able to tell for a while because I can't stop putting my foot into it and grin. A final word why I think it was vacuum related. After the repair, my car idled at 1000 rpm, instead of 700, and now, two weeks later, it is still at 1000. So in my opinion something definitely changed in the vacuum area.

But I also have to wait for the next 95 degree day with a full a/c load to see if all this wonderful achievement holds up. I would have preferred to have found an obvious fault to say AHA, and have a positive fix, but I'll take mine as it came, and hope it lasts.

My hope is that if this works for anyone else, it was worth my time penning it down. The whole routine cost less than $25 in parts, it was all time so I encourage others to try.

Good luck,

John

Nismo87SE

Usually when someone cleans the TB the idle increases. You will just have to back it down to the 700-800rpm range. You'd be surprised how much grime/sludge is in that intake collector, I'd also suggest cleaning the EGR tube also. My max ran like a champ after the TB swap and intake collector cleaning.

flyry110

i'm gonna try something like this.

Mr. Nismo

iTrader: (36)

Thanks for that info John!! I think that's what my car needs.

eric93SE

iTrader: (1)

My idle increased 200rpm when I ran carburator cleaner through the IACV. I then dropped it down from 1000 to 800. In order to clean the IACV, I disconnected the air hose leaving the main intake line heading to the IACV, then sprayed in the hose cleaner (with engine off) then reconnected hose and started her up. Allowed the engine to idle for a minute. Then repeated the procedure.

MaDMaX024

alright, i'm very interested in cleaning my throttle body.
how do i do it? i've got a can of autozone "carb cleaner" that i used when i worked on my boat engine. is this stuff ok?
assuming this is what iuse, how do i "apply" it.
also, how do i adjust my idle once the TB is cleaned?
thanks.