Can A Run On Dyno Find Idle Problems Etc?

[blitz r33]

hey guys my car has high idle ever since i took the plenum off plus the throttle body to clean the carbon build up on it.put it back on now it revs high,even put gasket sealant around the plenum thinking it was that and still nothing so im out of ideas whats causing it.

if i put it on a dyno is it possible for them to find the source?id ring them but they are on holidays.

[BezerkR32]

there is no point dynoing it for diagnosing a problem at idle, sounds like an air leak or possibly tps switch requires re-setting.

hey guys my car has high idle ever since i took the plenum off plus the throttle body to clean the carbon build up on it.put it back on now it revs high,even put gasket sealant around the plenum thinking it was that and still nothing so im out of ideas whats causing it.

if i put it on a dyno is it possible for them to find the source?id ring them but they are on holidays.

[blitz r33]

there is no point dynoing it for diagnosing a problem at idle, sounds like an air leak or possibly tps switch requires re-setting.

ok how do you reset the tps switch,yeah i think its an air leak as well but ive checked everywhere for it and the car is stock so no after market intercooler or anything like that where most people get an air leak so it narrows it down to the plenum.

i only took the plenum,throttle body and the aac valve off for a clean and i put them on tight and even put gasket sealant on the plenum after it was idling high and still no change so if it is an air leak i have no idea how its leaking.

i just hope it is the tps and it just needs a reset,can you tell me how do i do it please?

[blitz r33]

well does anyone know how to do a TPS switch reset?this idle problem is seriously pissing me off.

[blind_elk]

This is why:

...plus the throttle body to clean the carbon build up on it.

There are dozens of threads covering the same problem.

Why on earth people insist on cleaning something that is not ordinarily visible is beyond me.

[blitz r33]

This is why:

There are dozens of threads covering the same problem.

Why on earth people insist on cleaning something that is not ordinarily visible is beyond me.

yeah but they dont tell me how to do a reset and it wasnt like i was cleaning a little bit of carbon out of it,there was a shitload of it and thick.....the thing was putrid.

i wouldnt have bothered cleaning it if it was just a small layer of the shit.

[Swiper the Fox]

your throttle body is no longer sealing as you have removed the fine film of sealant on the edge of the butterfly. Air is bypassing it causing a higher idle.

Even though i may now have made you feel a little silly for 'fixing' something that is not broken...ive also saved you some $$ on a trip to the dyno.

Get a good 'uncleaned' throttle body to prove what ive just stated.

Edited January 1, 2010 by DiRTgarage

[blitz r33]

your throttle body is no longer sealing as you have removed the fine film of sealant on the edge of the butterfly. Air is bypassing it causing a higher idle.

Even though i may now have made you feel a little silly for 'fixing' something that is not broken...ive also saved you some $ on a trip to the dyno.

Get a good 'uncleaned' throttle body to prove what ive just stated.

dont feel silly at all,thanks i will try that and let ya know if you were right.but getting a throttle body that hasnt been cleaned is gonna be hard to get.

also ive had this problem for well over a year now,wouldnt the carbon have built back up enough by then to reseal it?was it a carbon seal or is there an actual sealant i have cleaned off?

its just that people have said its a carbon seal that builds up after years of use while others say there is a sealant made from something i cant remember.

Edited January 1, 2010 by blitz r33

[aleisha]

dont feel silly at all,thanks i will try that and let ya know if you were right.but getting a throttle body that hasnt been cleaned is gonna be hard to get.

also ive had this problem for well over a year now,wouldnt the carbon have built back up enough by then to reseal it?was it a carbon seal or is there an actual sealant i have cleaned off?

its just that people have said its a carbon seal that builds up after years of use while others say there is a sealant made from something i cant remember.

you could buy a 2nd hand one but i dont know much about the subject but could it be that your throttle body be playing up like for instance the butterfly valve is getting stuck?

if it is a new one should fix it or 2nd one that hasnt been cleaned that is.

[blitz r33]

been thinking.....if it was a carbon seal around the butterfly valve and removing the carbon build up caused my car to over rev than wouldnt the car have been over revving straight from the factory as it wouldnt have any carbon build up as it was new?

just a thought.

this is what i dont understand,are yous saying its a carbon seal or some sort of rubber or plastic seal?cause there was no seal around the valve only carbon build up,if yous were meaning carbon build up forming a seal than it doesnt make sense????

[Craig SLO33]

the acc valve could be fu*ked or out of adjustment,have u checked that out at all.theres no point putting up with just take ur car to someone who knows what theyre doing and c what they think..

[blind_elk]

yeah but they dont tell me how to do a reset and it wasnt like i was cleaning a little bit of carbon out of it,there was a shitload of it and thick.....the thing was putrid.

i wouldnt have bothered cleaning it if it was just a small layer of the shit.

But you can't see the crap ordinarily!

Was the car running fine before you did this? (Rule 1 of Motor Mechanics: If it ain't broke, don't fix it!)

[blitz r33]

But you can't see the crap ordinarily!

Was the car running fine before you did this? (Rule 1 of Motor Mechanics: If it ain't broke, don't fix it!)

id rather know if the seal people mention is a carbon seal or some form of other seal?if its a carbon seal wouldnt it build back up and fix itself?

[blitz r33]

the acc valve could be fu*ked or out of adjustment,have u checked that out at all.theres no point putting up with just take ur car to someone who knows what theyre doing and c what they think..

thats the problem,no one in my area knows what they are doing.

you mention an aac valve and they just stand there with a confused look on their face plus the fact no one wants to find the problem yet alone touch the car cause its an import.

the other day me and a mate checked the aac valve out,when my car was revving at 2500rpm i put the idle screw in to get it to 1000rpm but he turned it all the way back out to where it was originally and it only revs at 1100rpm which is alot better than 2500,still dont know why it use to rev so high but now it only revs to there.

[punk-kid]

there is no point dynoing it for diagnosing a problem at idle, sounds like an air leak or possibly tps switch requires re-setting.

in respose to the above statement .. what a load of crap!!!!!

Dyno's are designed to be used as test/diagnostic equipment.The dyno is not just to run you car up on almost all dynos these days have a/f , load cells, brakes. They were designed for this use long before they were used for tuning. in the early days before load cells and a/f meter we used them as diagnostic only tools. Following are examples of how modern dynos are used and how experienced staff interperate the results not guess ( only examples ) e.g. your car doesnot idle. you would first ask the customer the questions does it idle at all , it is rough , etc. As long as there is some idle all you need to do it put the car on the dyno and put the a/f probe in with the scan tool on. Should the a/f change out of range on slow cruise and drop idle (or 02 voltage be out of spec or heat range). ( faulty 02 ) Should the aac valve over compesate about say 55% open at idle. ( possible vacum leak or pcv open )

With people giving inaccurate and advice like this no wonder mechanics and tuners scratch there head when people come into there workshop blabbing rubbish they read from someone who has never used a dyno.

Dynos , scan tools and product knowledge will cut the cost of diagnostic time down . this also means less wear , less money, and less enviro impact . Just remember its your car. Like i say to all my customers you dont need to listen to me, listen to free advice.. hey if its any good .. they would charge for it.