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Discussion Starter · #1 ·
I checked the inside of the throttle body over the weekend before my mechanic put my new dizzy cap back on and it was well gunged -up (black) could this be a cause of stuttering misfire like performance ? the problem has returned after we thought we had cured it :(
Cheers
Matt .
 

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I checked the inside of the throttle body over the weekend before my mechanic put my new dizzy cap back on and it was well gunged -up (black) could this be a cause of stuttering misfire like performance ? the problem has returned after we thought we had cured it :(
Cheers
Matt .
Hi Matt

It will be a major cause of the stutter and misfire. I had to clean mine sevral times, and the IAC valve on the bottom of the TB to get it all smooth again.

Mike
 

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depends on what level of gunk you are talking about. If its a light smear then thats pretty normal if its never been cleaned but if its think with chod it will cause problems like Mike suggests.
 

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Discussion Starter · #4 ·
Thanks for the replies , he's going to clean it tomorrow so hopefully that will sort it (i hope it does cos i don't what else it could be at the moment:confused:) and i've got a long drive to work in a diesel LDV van to look forward too now , no sounds no heater and its faster to get out and walk up any hills :rolleyes:
 

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Discussion Starter · #5 ·
Had the throttle body cleaned out on Thursday and the car was great again but only until last night when the misfire came back :mad: . it does it now when the car is ticking over and it almost cuts-out , plus i'm sure i can hear a rushing air noise from the throttle area that wasn't there before:confused: I've booked it in with a different mechanic next Wednesday for a second opinion , he said he'd check through everything and had i done the coil ? . I might leave the keys in its door tonight in the hope it gets nicked and burnt-out LOL .
 

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sounds like an air leak of some sort, have you had a look at the elbow that goes from the VAF to the TB to see if theres any cracks in it? Could be something simple like that.
 

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Had the throttle body cleaned out on Thursday and the car was great again but only until last night when the misfire came back :mad: . it does it now when the car is ticking over and it almost cuts-out , plus i'm sure i can hear a rushing air noise from the throttle area that wasn't there before:confused: I've booked it in with a different mechanic next Wednesday for a second opinion , he said he'd check through everything and had i done the coil ? . I might leave the keys in its door tonight in the hope it gets nicked and burnt-out LOL .

Hi Matt

You can check that the seal is good on the TB, with the engine running, spray some WD40 around the joints, if the revs go up, you have a leak.
I had to seal my TB twice, and found it only really sealed with a gasket.
The air noise is there on mine, and I think it is as it should be, with the air moving around the bypass now its clean.
How much crap came out of yours?
Mine, I had to scrape it off with a screw driver first, came of in chunks the size of my thumbnail!

Stick with it mate, you will get there.

Mike
 

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Discussion Starter · #8 ·
It was really badly gunged-up , had to be scraped -out first so probably hadn't been done before, thanks for the info i'll try and see if there is an air leak. What is confusing is that the car was so good after the clean-out for about 60 miles or so and then it started playing up again . I took it for a drive yesterday and it was better than on Saturday , it doesn't like ticking -over and is better (though not 100%) once you get going .
 

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if the TB came off the car you will need to set the idle/throttle stop and maybe the mixture screw again as its now breathing better (leaner).
 

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if the TB came off the car you will need to set the idle/throttle stop and maybe the mixture screw again as its now breathing better (leaner).

Windy is dead right! It took me a few hours on the road with a screwdriver to get these spot on. And don't forget, I presume you reset the ECU, that it then takes 200 miles or more to "re learn" the idle.

Mike
 

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Windy is dead right! It took me a few hours on the road with a screwdriver to get these spot on. And don't forget, I presume you reset the ECU, that it then takes 200 miles or more to "re learn" the idle.

Mike
Karma for Windy!

30 miles mixed roads/driving is all it takes for the ECU to re-learn.

TB is a pain to setup when removed because the TPS/throttle stop and mixture can all get thrown out of sync and makes you think you have problems that are worse than they actually are.

Its a common problem on cars where people swap for a bored TB and FPR. Getting the set-up right can take hours/days to perfect.
 

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Discussion Starter · #12 ·
Windy is dead right! It took me a few hours on the road with a screwdriver to get these spot on. And don't forget, I presume you reset the ECU, that it then takes 200 miles or more to "re learn" the idle.

Mike
I disconnected the negative battery lead , then put my foot on the brake for about 30 seconds and then re-connected it , is that right ?
 

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Yup, but then you need to go out for a drive, not just sit there with it idling or it wont learn anything.
 

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Discussion Starter · #14 ·
I took it out for a short drive after i did that and then today its done about 40 miles and does seem to be a better but still missing , which must mean it is a set-up problem since the TB has been off and cleaned rather than something else unrelated , i think i'll print off these pages and show them to the mechannic its booked in with on Wednesday otherwise he's going to spend time looking in the wrong places .
 

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Discussion Starter · #15 ·
Had it all checked over today by another garage , he couldn't find anything specific wrong with it , nothing came up on the diagnostics and he said it only missed once when he test drove it . The only advice was it could be the MAF sensor playing -up as he "tapped it and heard a tiny rattle " . Weirdly since i've picked it up and driven it home its almost totally normal again except for the revs going up and down a bit when its idleing :) I think i'll just leave it now , use it and see what happens as it seems to be getting better by itself ha ha . Maybe it is just the ECU re-learning as mentionned above ?
 

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All the air flow meters rattle when you tap them, theres spring loaded cone inside them!
 

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That rushing noise... There is a 10mm or so vacuum pipe that comes of the back of the throttle body and goes into the bulkhead, you sure thats been put back on? i forgot to do that once and it made that noise
 

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Discussion Starter · #19 ·
That rushing noise... There is a 10mm or so vacuum pipe that comes of the back of the throttle body and goes into the bulkhead, you sure thats been put back on? i forgot to do that once and it made that noise

I'll have a look for that today ,
Cheers
Matt .
 
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