Dealer says "dirty throttle body" and needs "to flush/clean the injectors".....

WheelinTJ2004 · 08-15-2008, 01:40 PM

Am I getting ripped off?

Is this up there with Blinker Fluid?

My TJ is stalling when I leave it in neutral and take my foot off the gas. They think it could be the idle position sensor, but aren't sure, and don't want to charge me for one if they know it's not broke.

"dirty throttle body" and needs "to flush/clean the injectors" is their solution for now.

Thanks!

**Jerry Bransford** · 08-15-2008, 01:49 PM

Yep, cleaning the injectors is right up there with blinker fluid. The "clean the injectors" thing is a sure-fire revenue producer for dealers but there's usually no need for it since injectors rarely get dirty with today's gasolines that contain a sufficient amount of fuel injector cleaner to keep them clean.

An engine stalling at idle is usually, 99 times out of a hundred, caused by a dirty IAC (idle air controller) which is attached to the throttle body. The IAC is what provides all of the air to the engine at idle so if it's too dirty from the black gunk that forms inside the throttle body to function properly, a bad idle or an engine that dies at idle is the usual result.

Cleaning the IAC is easily done with a toothbrush and spray throttle body cleaner after removing it from the throttle body which is easily done by just removing the two torx-head screws that hold it in place. Once it is clean, together with the hole the IAC's plunger fits into, use the remainder of the TB cleaner to clean out the inside of the throttle body per the instructions on the can.

So yes it's likely the inside of the throttle body is dirty together with the IAC, but I wouldn't worry about the fuel injectors being dirty in the least.

One last thing... the IAC is the gizmo mounted onto the side of the throttle body furthest away from you as you stand at the driver's side of the engine looking at the throttle body. Use a new/sharp torx bit driver to unscrew the two screws that hold it in place, being careful not to strip them out as the screws are tight since they are held in by Locktite. Unplug the IAC and then just spray the plunger with cleaner and gently clean all the black gunk off with the cleaner and a rag/toothbrush until it's clean. Don't push/pull/turn the plunger, clean it gently though it's not fragile.

fromme · 08-15-2008, 01:50 PM

Clean the throttle body yourself, the idle air bypass valve, and run some Chevron Techron injector cleaner through it. You'll save a bunch of money and then you'll know if that is the problem or not.

Ahhh, Jerry beat me to it.

**Unlimited04** · 08-15-2008, 01:51 PM

they're ripping you off. the TB is probably dirty, just got to Autozone and buy some Throttle Body Cleaner, pull the air tube off, shine a flashlight down there, cycle the throttle body blade open using the throttle cable, then spray the black carbon buildup away with the TB Cleaner spray.

takes 15 minutes max, and it don't cost more than 5 bucks.

on one side of the TB you'll see an opening that passes from the top to the bottom - and there is a sensor on the outside of this machined slot. Thats the IDLE PASS THRU, clean this area well with the TB cleaner. I bet your idle gets better and you stop stalling.

hyzershot · 02-19-2009, 08:54 AM

bumping an old thread for a new question....

so I had my IAC out last week, if I had read this thread I would have know not to mess with the plunger but the fact of the matter is that I did..... while I was cleaning it I pulled it off, I was able to get it back on but I'm not 100% certain its in the exact placement.
My jeep has been running about the same only a little worse now... when I start in it, the idle jumps to 2k and stays for a minute, while at a red light while engine is still somewhat cold it likes to rev up to 1k and lowers itself to 500. when it warms it quits doing the idle jump but while driving and accelerating it feels like it has a miss, plugs are relativity new so I doubt they are any concern....

I guess my question here is will a new store bought IAC possibly rectify my situation?

saharaTJ7638 · 02-19-2009, 09:31 AM

Yes If you want to buy one. Or... you could buy my old throttle body with the sensors already on it. Haha no but seriously I think the sensor is under 50 bucks at autohell I mean autozone.

jeepfanatic · 02-19-2009, 09:37 AM

[QUOTE=hyzershot;6616581]when it warms it quits doing the idle jump but while driving and accelerating it feels like it has a miss, plugs are relativity new so I doubt they are any concern....
QUOTE]

This sounds like it could possibly be a coolant temperature sensor, the sensor could be giving bad info to the computer making the motor think it needs to run rich to simulate a cold running engine. Similar to a "choke" effect.

jrb470 · 02-19-2009, 09:49 AM

Hold on a sec... What the dealer wants to do is probably a "Fuel Induction Service" that basically runs a "detergent" through the induction system which will do everthing they said AND clean any carbon of the intake valves. This too can become built up over time and cause driveability issues, engine misfires and error codes to appear in the ECM. Dealers/Repair centers usually want to charge $99 to $120 bucks for this service.

Just a personal note: I was a skeptic for a while until I witnessed before and after shots of intake valves on a test conducted by BG (manufacture of automotive products)

Just my $.02!!

**Jerry Bransford** · 02-19-2009, 11:01 AM

Personally, I would NOT (!!!!!) pay the dealer to do a fuel injector cleaning service.

I used to work with a whole bunch of new car dealers here in San Diego and they all use that as a way to boost the average service bill. That particular service is like 99% profit for them. Why not? Because modern fuel injectors running modern gasolines that are loaded with fuel injector cleaner additives just haven't gotten dirty enough in many years to require this service. Fuel injectors USED to get dirty but the gasoline manufacturers started adding more cleaners and that took care of the issue many years ago. Young mechanics I know say they have never seen a clogged fuel injector cause a problem and old mechanics pretty much agree (and I talked with a bunch in that job) they haven't seen a clogged injector in many years.

Dealers LOVE the fuel injector service as it's a huge money maker for them. Unfortunately, it's rarely actually needed.

Edit: So far as cleaning the interior of the throttle body goes, yes that should be done every so often as it does get grimy inside there which can cause the engine to not run all that well. But it's so easy to clean it on your own with an $8 can of aerosol Throttle Body Cleaner you can buy at any auto parts store that it's not worth paying the dealer to do it. Instructions for how to do this easy fast job are on the can itself.

jrb470 · 02-19-2009, 11:13 AM

Quote:

Originally Posted by Jerry Bransford

Personally, I would NOT (!!!!!) pay the dealer to do a fuel injector cleaning service.

I used to work with a whole bunch of new car dealers here in San Diego and they all use that as a way to boost the average service bill. That particular service is like 99% profit for them. Why not? Because modern fuel injectors running modern gasolines that are loaded with fuel injector cleaner additives just haven't gotten dirty enough in many years to require this service. Fuel injectors USED to get dirty but the gasoline manufacturers started adding more cleaners and that took care of the issue many years ago. Young mechanics I know say they have never seen a clogged fuel injector cause a problem and old mechanics pretty much agree (and I talked with a bunch in that job) they haven't seen a clogged injector in many years.

Dealers LOVE the fuel injector service as it's a huge money maker for them. Unfortunately, it's rarely actually needed.

I agree with you...it is a HUGE profit center for them and it is very easy to do a TB cleaning yourself like you stated earlier. I just wanted to make the point that I witnessed a BG Test and was amazed at the results after the head was torn-down again. It was back in the late 80's, early 90's though and like you said... gasoline is much cleaner.

hyzershot · 02-19-2009, 11:19 AM

something new.... always something right? lol

so I drove to parts store to buy a new IAC... I figured even if it's not 100% the problem the fact I messed with it before was sure to not help the equation.. while driving there and back my engine light went on, to me this is somewhat good news because now I can drive over to my buddys shop and see what the error code has to say (I'm clueless on reading codes).

**Jerry Bransford** · 02-19-2009, 11:21 AM

There's no need to buy a new IAC, you only need to remove it and gently clean its solenoid actuated plunger and the hole in the throttle body it fits into. They get dirty but they seldom go bad where they actually need replacing. Save your $$$, return it.

**Yury** · 02-19-2009, 11:30 AM

dont know if this helps but i had a similar problem on my tj. it would start run normal for a minute and then start idleing irraticaly almost to the point of stalling. i went the iac route and even the throtle positioning sensor....and nothing. then on a hunch i disconected the plug from the 02 sensor and everything went back to normal. i replaced my sensor and was on my merry way. the checkengine light did not come on or give me a error code until i disconnected the 02 sensor

hope this helps.

p.s. as far as the iac motor i did what you did with the plunger. however a couple of times reving the throtle body it set itself back to normal.

**mrbates** · 02-19-2009, 11:41 AM

Quote:

Originally Posted by Jerry Bransford

There's no need to buy a new IAC, you only need to remove it and gently clean its solenoid actuated plunger and the hole in the throttle body it fits into. They get dirty but they seldom go bad where they actually need replacing. Save your $$$, return it.

Jerry, i think he said he cleaned it already and when he did he screwed up the plunger.

OP--you can have the jeep display the error code for oyu by turning the ignition on/off three times and leaving on. it will display the code. you can google it or bring it here and figure it out.

hyzershot · 02-19-2009, 12:10 PM

scangaugeII says p0122
I googled it and, it says TPS

http://www.obd-codes.com/p0122

I can still take this IAC back... I thought removing the plunger messed it up, but if it's self adjusting as Yury says there is no need for replacement as I already cleaned it.

Quote:

Originally Posted by Yury

p.s. as far as the iac motor i did what you did with the plunger. however a couple of times reving the throtle body it set itself back to normal.