Guru Posted January 25, 2006 Share Posted January 25, 2006 Last night I noticed at some lights that she felt and sounded a bit lumpy on idle. Revs were missing a beat and I could feel the difference through the seat. A quick badly sounding rev later and she was purring normal again. Got home and nothing strange. This morning I was sitting idle picking up a friend and it did it again. I got out the car and could hear the difference from the exhaust again. Revving slightly didn't help so I turned the engine on and off which worked. Then at a roundabout it did the same thing! Couldn't switch off and on so I was driving with it. The car was not giving 100% until about 5 mins later when it suddenly kicked in under acceleration. Now I am getting worried, what do you reckon? EDIT: Nearly forgot its just been serviced and has new spark plugs. Not getting a warning light and temps look normal. Revs don't seem to dip with it either. Link to comment Share on other sites More sharing options...
Nic Posted January 25, 2006 Share Posted January 25, 2006 Matt, my guess is that you have a bad connection to one of the coil packs, which is causing the car to run on 5 cylinders every now and again. The plastic connectors to the coil packs get very brittle over time, possible that one has broken when the plugs were changed. New connectors may sort the problem, if they don't it could be a dodgy coil pack. Link to comment Share on other sites More sharing options...
tbourner Posted January 25, 2006 Share Posted January 25, 2006 Sounds a bit like my issue. It hasn't happened for a month or 2 now though. Link to comment Share on other sites More sharing options...
letmeshowyou Posted January 25, 2006 Share Posted January 25, 2006 could even be a dogy plug too... Link to comment Share on other sites More sharing options...
tbourner Posted January 25, 2006 Share Posted January 25, 2006 Too intermittent for that. It's a perfect on off! It'll be lumpy for about 3 minutes then be fine again!! I guessed at a valve sticking, but have no idea which one would cause it. Otherwise it 'feels' like an electrical problem; dry joint or similar. Link to comment Share on other sites More sharing options...
letmeshowyou Posted January 25, 2006 Share Posted January 25, 2006 you'd be surprised at the symptoms a dodgy plug can give. Worth a look at anyway. Link to comment Share on other sites More sharing options...
Guru Posted January 25, 2006 Author Share Posted January 25, 2006 Matt, my guess is that you have a bad connection to one of the coil packs, which is causing the car to run on 5 cylinders every now and again. The plastic connectors to the coil packs get very brittle over time, possible that one has broken when the plugs were changed. New connectors may sort the problem, if they don't it could be a dodgy coil pack. Yeah I thought not running on all cylinders too. CW replaced the plugs and I think he changed the coil packs too. I have emailed him to see if he knows. Sounds a bit like my issue. It hasn't happened for a month or 2 now though. Mine doesn't drop revs like yours did though so may be different. I can't just reset the ECU either as I have the Apex'i ECU lol Link to comment Share on other sites More sharing options...
tbourner Posted January 25, 2006 Share Posted January 25, 2006 hmm OK then. Hopefully mine is just plugs!! I know the gap wasn't checked when they were put in (NGK not iridiums). Maybe I'll have a go. Link to comment Share on other sites More sharing options...
Daston Posted January 25, 2006 Share Posted January 25, 2006 Had this in my MR2 turned out to be crap on the end of a spark plug Link to comment Share on other sites More sharing options...
Terminator Posted January 25, 2006 Share Posted January 25, 2006 Strange coincidence, mine was running on five cylinders yesterday morning. No codes, but would not go back to all even after an ECU reset. Took out the plugs and they all looked fine. Checked compressions all fine. Put in a spare set of plugs and it fired up on all six. I replace the new plugs with the old ones one by onethen plugs one to find one of my four month old denso's had given up completly. Some sort of internal failure. Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 25, 2006 Share Posted January 25, 2006 It had 5 out of the 6 coil connectors renewed, it looked like the No6 one was OK so i left that, from memeory! It had new NGK plugs, too. I suspect, subsequent to our chat and having time to mull it over, coils, plugs, or connectors, so it will need the coil cover removing in order to have apeek in there. Link to comment Share on other sites More sharing options...
francis Posted January 25, 2006 Share Posted January 25, 2006 I have a similar problem... it only happens when cold, after starting it up it idles at about 1500rpm and then when it drops it get a bit lumpy and you can see the revs fluctuating very slightly... After 15 minutes or so it is absolutely fine and idles perfectly... I've changed the plugs which didn't improve the situation, I've just changed the MAF and reset the ECU - will let you know if this improves things... Link to comment Share on other sites More sharing options...
Guru Posted January 25, 2006 Author Share Posted January 25, 2006 Yeah thanks for responding so quick Chris much appreciated I got home ok with no sign of the problem. I will sit on it and use the Apexi to see if it makes any difference to boost and rev levels when it goes lumpy again. When I am next down in Shrop (week or two) I will give you a call Chris Link to comment Share on other sites More sharing options...
Guru Posted January 30, 2006 Author Share Posted January 30, 2006 FYI it was a loose connector to one of the coil packs which meant the ECU shut down to only 4 cylinders Thanks Chris for sorting it Link to comment Share on other sites More sharing options...
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