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Discussion Starter · #1 ·
Usually my car idles perfectly smooth, but occasionally it will idle really roughly. Even if you rev the car, it is still very rough up until about 1.5k RPM. It appears that a cylinder may not be firing properly as the engine shakes a fair bit when this happens.

I've replaced the spark plugs and run some injector cleaner through the system. This has not helped. Next step is to replace the fuel filter (unlikely to help but i need to do it anyhow), and then I'm replacing the spark plug leads.

Any other suggestions as to what it could be? (sticky injector mabey?) Remember it doesn't happen always, only sometimes. Generally when the engine is hot, and usually if I turn the engine off for a few minutes, when I start it again it will be normal ... so it's not really long enough to have any major temp difference.
 

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FlySwat said:
Plug wires
Any time I've had grief with plug wires, it's been a higher (say above 4000 RPM) rather than at low Rs and then clearing up at higher Rs.

That having been said, I don't have any other suggestions (I woulda said a shaky/grubby plug, but he claims plugs were replaced).

I would suggest he pull the plugs anyway, to check cleanliness and colour.
 

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I also had problems in low revs and they disappeared when going into higher revs. My problem were the wires


GRZ JORDY
 

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shaky idle

As these guys have said :
Make sure the plugs are properly gapped & torqued. Next, would be the ignition wires, followed by the distributor cap & rotor.
If it were fuel problems, chances are it would be showing up while driving also, but you never know. The vacuum lines & TB boot should be inspected also for leaks. Try pulling the codes, as the emission devices may need attention. Also lastly, check your coolant's level, as this can affect the ISC valve.
Good luck ! Report back with what you've come up with.
 

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Discussion Starter · #6 ·
Ok, I've replaced the spark plug leads. So far, so good.

Also, is the oxygen sensor the plug that comes out of the top of the exhaust manifold / turbo, then has a lead that runs up and clips on the right side of the rocker cover, then goes into a bunch of cables? If so, it was disconnected! Have reconnected that, will hopefully fix my stuffed fuel economy.
 

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Discussion Starter · #7 ·
Ok update. The problem still happened after I replaced the leads and fixed the o2 sensor.

I had a good close look at the throttle body boot, and there was a small crack right where it attached to the throttle body, going under the clamp that holds it on. So I figure it is opening up sometimes and allowing air through when it's hot.

I tightened the clamp up to try and hold it together better. so far so good. Fingers crossed this fixes the problem.
 
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Ionos said:
Ok update. The problem still happened after I replaced the leads and fixed the o2 sensor.

I had a good close look at the throttle body boot, and there was a small crack right where it attached to the throttle body, going under the clamp that holds it on. So I figure it is opening up sometimes and allowing air through when it's hot.

I tightened the clamp up to try and hold it together better. so far so good. Fingers crossed this fixes the problem.

Thats what I meant for "check for leaks on the intact tract".

You need a new TB boot pronto, it will continue to tear until your car wont run at all.

However, I have a very low milage one for sale in my sig :)
 

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I have this same problem... the rough idle, but only after I have been driving slowly (off boost) and it will run fine until you stop and then idle roughly, as if one cylinder isn't firing. The car has new plugs and leads, could is be the distributer etc,?
 

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Throttle Body Boot. $60 or so from dealership. Dealership only item.

Happened to me, as well. It's a common problem with 1G 6's. If you take the old one off, there'll probably be a large crack in the back/underside of it. That's the usual area. Easy fix, thank goodness. If you have to wait on the replacement, I'd suggest duct-taping the crap out of it, and turning down your boost (if you've got your boost at a non-stock level.)
 

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NOOBS, pay attention to the DATE of these things!!! This thread is 3 years old!!! :freak: I know you mean well, but cmonnnnnnnnnnnn peopleeeeeeeeee!!

dvs, if you need help, post a new thread, and we will take a look at it. the old threads like this will be ignored.
 

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i know, i realized that afterwards, but you seem intelligent, so i figured youd get what i meant. but its for you as a noob too, lets all help as much as we can, and make sure things are posted in the right ways, so that people get the help they need (at least in this forum). if I was reading this thread, and posting on it, I would check back to see the progress, etc., and obviously that would not work out, and so on. these posts also bump the threads back up to the top, which pushes relevant issues down. vets will check the date and ignore them, and noone gets their help. anddddddd thats enough of me talkin.
 
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