throttle body cleaning

[Budtee]

I have an 89 8v.  I started to clean the throttle body and found there are many hoses and mounting studs that hold the air box very firmly in place.  What is the best way to get access to the throttle body?

 

 Also, I plan to change the spark plugs.  It has the original RN 12 YC champions in it now. (10,800 miles)   Should I replace them with the same champion plugs or is there a better plug?

[Reaper1]

To remove the airbox to get at the throttle body:

 

take off the corrugated plastic tube that runs behind the battery and the air box.

take the clamps loose that hold the front of the air box on and remove the front of the box along with the air filter

loosen the hose clamps on the corrugated rubber hose between the air box and intercooler (you *can* get away with only removing the intercooler side)

loosen the clamp holding the one vacuum line to the side of the box, remove that line and the other rubber line that goes to the anti-surge valve (blow off valve)

loosen the hose clamp on the turbo inlet hose on the side of the air box

take loose the PVC tube between the valve cover and the air box

loosen the hose clamps holding the short rubber hose between the air box and the throttle body

I suggest using something like WD40 on the 2 grommets  that hold the air box to the bracket from the "head side" of the bracket

using a prying device, *carefully* pry the air box out of the rubber grommets

Once you have the 2 plastic pins on the back of the air box out of their grommets, you can pull the box toward the front of the car and it should come off of the throttle body allowing you access.

loosen the hose clamp under the air box going to the small hose (part of the blow off valve plumbing). then you can completely remove the air box from the car.

 

Be careful of the plastic vacuum lines as they will most probably be very brittle. They can be replaced, but I figured I'd give you a heads up.

 

Also, there *should* be a piece of foam looking stuff in the bottom of the air box where the PCV tube goes. Most of the time this thing is completely oil soaked and could be  gone all together. Be sure to clean this area up and replace that filter. Now is also the time to inspect the PCV adapter on the air box. They have a nasty tendency to either break off or come loose off of the box. JB weld, super glue, other types of epoxy can solve this issue.

 

As for the brand of spark plugs...that's opening a can-o-worms. It's really a personal preference. I personally like NGK spark plugs. Other swear by Champion or Autolite.

 

Edited August 29, 2016 by Reaper1
missed a step (see edit history)

[Guest EmmettTC]

NGK for life, they work great with these engines as long as the gap is always to spec or even a bit smaller if you beat on it a lot.

[Hemi Dude]

Good explanation Reaper1. Having worked on these and similar cars for many years, I couldn't have written the air box removal much better. Just one thing on the 'prying loose' of the air box from the 2 grommets. Be sure you don't force the tip end of the tool into the plastic box. That end should be digging into the metal bracket. I also do a reciprocating motion with my hand on the tool as I try to get the box out of each grommet while alternatingly spray the WD-40 onto the plastic pegs and the grommets. Generally it takes a little time to make them slippery enough to come out. BE PATIENT! The grommets are replaceable if they should break, but the dealers undoubtedly don't stock them any more. I couldn't even get the 5/16" fuel hose clamps. NS1 is what I was told.

[Guest GregTC]

On August 29, 2016 at 11:06 AM, Budtee said:

I have an 89 8v.  I started to clean the throttle body and found there are many hoses and mounting studs that hold the air box very firmly in place.  What is the best way to get access to the throttle body?

 

 Also, I plan to change the spark plugs.  It has the original RN 12 YC champions in it now. (10,800 miles)   Should I replace them with the same champion plugs or is there a better plug?

I have always believed to use the plug types that the engine was designed with no matter what brand vehicle but that my opinion 

[Hemi Dude]

6 minutes ago, GregTC said:

I have always believed to use the plug types that the engine was designed with no matter what brand vehicle but that my opinion 

And I agree with you 100%.

[Budtee]

Thank you!  Reaper1's instructions couldn't have been better.  I was able to clean the throttle body easily.  The forum came through again!

 

I installed NGK plugs as my local Advance did not have Champions in stock.  Easy to change if I see deterioration performance.  Cleaning the throttle body and replacing the plugs has made it run better. 

[Hemi Dude]

NGK plugs are probably just as good and if you installed platinum tip electrode ones, even better. I run so many years on the same plugs, it has probably been a decade or more since I changed them.

When I had my 1958 Plymouth Fury, I would run it 50,000 miles before changing the plugs. Never had any problems.

[Reaper1]

Please note that what I'm about to explain I personally have never experienced in my own vehicle, but I have seen this happen.

 

While it is true that almost all new cars specify platinum or iridium plugs, including turbocharged ones, I have heard reports from other owners of 2.2 8V turbo Chrysler engines where the platinum tip has broken off and some claim they can be a hot spot in the combustion chamber causing preignition. Please keep in mind that these were also NOT stock engines. I have personally SEEN a platinum plug fail like this while I was working in the boating industry.

 

Having said that, in a stock engine, with a good quality plug I honestly don't think it's much of an issue.

 

One thing to keep in mind with these types of plugs: DO NOT gap them! You can check the gap, but NEVER pry between the ground strap and electrode tip. If it's a double platinum plug, really all you can and are supposed to do is check the gap. The same goes for iridium type plugs.

 

Also, do not expect these plugs to work miracles. Unless your old plugs are totally trashed they will not really provide an increase in power or economy. The sole reason these plugs exist is to extend the service life of the plug to reduce the service intervals needed on new vehicles. So, if you don't want to have to change plugs every year or so, maybe these are worth looking at. Because my personal goals for my cars are typically elevated beyond stock I do not run these types of plugs due to the added possible failure point of the plug and they don't increase performance (I only run copper). As a matter of fact, in my Daytona a set of plugs would only last about 6 months. However, I was modifying the plugs by cutting the ground strap back to just be over only 1/2 of the electrode, and then I also put a point on the ground strap. Basically a "poor man's race plug" by exposing more of the electrode this is supposed to unshroud the flame kernel that starts there which in theory can help make sure the combustion not only happens when it's supposed to, but that it is complete as well. Those modifications reduce the life of the plug, plus I ran my engine pretty hard. I also try to index them the best I can. I don't own a set of shims, but I can usually at least get the plug gap towards the combustion chamber at the very least. I like to try and aim the gap at the exhaust valve.

 

Anyway, just trying to play devil's advocate and give some tips for the correct use of that type of part if a person so chooses to run them.

 

Oh, one last thing...most of us probably already know, but please don't fall for the "more ground straps, the better" trap. That is totally BS for most engines (including ANY of ours) and can actually end up causing issues. Don't waste your money or time on them.