Rough Idle And Random Miss

[Hyena]

Hey guys,

Here's another rough idle and missing problem!

I've only had my T a few months, I put in a K&N panel and got a generic edit and shortly after noticed a bit of a miss and intermittent rough idle. I thought it was probably the original plugs, which I just had regapped at the time. Last month I got a custom tune with new plugs and the miss seems to have gotten progressively worse. The guys at CV said you'll get a bit of a miss when you close the plug gaps up but this is a bit beyond that. Now when you pull up at the lights it idles ok for a few seconds then goes a little rough and occasionally has a really big miss where it almost stalls. This is independant of driving it hard or cruising around taking it easy.

The other big symptom is periods of running really rough/fluttery like it's down a cylinder or 2. I thought this was probably valve spring float as it first did it after a caining but it now does it occasionally when just cruising along. This morning I was rolling along in 3rd for a while then went to accelerate lightly and it started to flutter. I backed off then accelerated, still flutter, backed off again and accelerated and it was back to normal.

I've just cleaned the throttle body and it made no difference.

The car isn't particularly modded - K&N, wog cooler, 3.5" cat and custom CV edit making 250rwkw

Does this sound like a valve spring issue or maybe a coil on the way out ? Or something else ?

Cheers

Jay

[senna_T]

hey Hyena, I remember you from Fordmods days! anyway, sounds like you have a dud coil, from previous posts, I think this was more an issue with mk1's and show its self at random times, I'd pull the coils out and check for any issues with the contacts.

There will no doubt be a few ppl along soon to shed some light on how to diagnose bad coils

[Hyena]

Yeah I thought it was more likely coils given the symptoms. Mine is a Mk1, just - June 04 with 60k on the clock. I thought too that it may have gotten worse after the edit because the coils were moved around while changing the plugs.

[shadyxr]

Hyena, I have the same problem. My idle is just above 500 and sometimes it stalls. My tuner also cleaned the throttle body for me when this problem came up but it's still the same. Have not had a chance to get back to them yet. Mine also stalls when starting hot. I think it might just need a few more revs at idle.

[CV PERFORMANCE]

Could be a few different issue's best bet is to bring it in for a day for us to have a look at things such as faulty coils,throttle body,plugs, solinoids etc etc

CV PERFORMANCE

[Hyena]

Hey guys,

just an update for those who may have similar problems, I took it into CV and apparently I have a leak around the turbo. I thought the bonus noises were part of the edit but apparently not!

$400 to fix which is a bit of a bugger though!

[gravelrash]

CV, whats involved in actually fixing this problem ? I take it it's more than just tightening a few bolts which is what usually fixes these problem.

\

I suspect I might have the same problem Hyena has, trouble is im in QLD. Is there a gasket in there that blows out or not?

Edited 27/11/07 11:37 AM by gravelrash

[BFHOON]

have u noticed that it happens when it goes from a cold start to nearly warm, then all day its ok untill u have a cold start again.

im thinkng around 1/4 temp.

[Hyena]

Nope, it only does it (the fluttering) when rolling along at low revs. Con mentioned something about it happening when it goes into lean cruise mode - which is exactly when it does it. It actually does it at the same spots on the way to work every day! I take off from the lights then cruise along for a bit then come to a slight grade and go to accelerate and then it starts fluttering (feels very similar to what it did when I first had the edit and didnt gap the plugs and it was blowing the spark out)

The stalling and some of the idle roughness was eliminated by raising the idle but he said the rest of the missing at idle is just what you get form gapped plugs.

[BFHOON]

think about that , im not saying this is the problem but if its the same set of lights it may be the same temperature.