BOB B Posted September 5, 2008 Share Posted September 5, 2008 Hi experts, I need some advice/help. The story so far. The build up, around 3 months ago I went full BPU, Im UK so full de-cat, fuel cut defencer, and boost controller, before I had this done I had a full service done including all belts. Since then I have had a problem with missfires, started off realy minor, hardly noticable, then over a distance of around 1000 miles it became worse untill the engine ran for about 10 seconds sounding like a shaken tin bucket full of spanners and lost power. It then sudenly became ok, so went for drive no missfires, at this point I changed all the plugs Ik 24s and the connector housings. Everything seemed well for a while then I found that the minor missfire came back it got worse over a 1000 ish miles and then yesterday driving along and then came the bucket of spanners, back again. Pulled over lasted about the same time and then everything came back fine again. It dawned on me today could this be anything to do with the timing and timing belt being changed. Any help or relevant sujestions/advice would be greatly appreciated. A now unconfidant Supra driver Bob. Quote Link to comment Share on other sites More sharing options...
Nic Posted September 5, 2008 Share Posted September 5, 2008 (edited) If it's been running okay, it won't be the timing belt that's the problem. It is obviously an intermittent faults somewhere. As I read my first thought was plugs, when you said you'd changed them my second though was the coil pack connectors, the plastic on these becomes brittle over time from the engine temps and can cause bad connection which leads to misfire. http://mkivsupra.net/vbb/showthread.php?t=61141 Edited September 5, 2008 by Nic (see edit history) Quote Link to comment Share on other sites More sharing options...
Homer Posted September 5, 2008 Share Posted September 5, 2008 Certainly intermittant so you can rule out the timing for sure. Have you changed the coil pack connectors (seems so). How about the plugs, have they been swapped since the orginal issues happened (I doubt this as a cause as well) Ignitor or coil pack might be another thing to look into, but it's a strange situation you have there. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted September 5, 2008 Share Posted September 5, 2008 Does it get worse when its hot, and is it definitely a misfire? IE stuttering and holding back? Quote Link to comment Share on other sites More sharing options...
Scooter Posted September 5, 2008 Share Posted September 5, 2008 (edited) there was a guy with a uk spec that had a long running misfiring problem (that he eventually solved)............I remember red manual (i think) & low mileage but his user name escapes me right now......off to search....... Edited September 5, 2008 by Scooter (see edit history) Quote Link to comment Share on other sites More sharing options...
BOB B Posted September 5, 2008 Author Share Posted September 5, 2008 (edited) Ive changed the coil pack connector housings when I did the plugs. It doesnt seem to be an intermittant fault it just starts off hardly noticable then just steadilly gets worse over the period. I first notice it at say traffic lights, it just pops every second or so then as time goes I notice it just driving along then aventually a bucket of spanners for a short time then it seems to start biulding again. Sorry forgot to mention Im prity sure its a missfire, sounds as you said tricky and when it starts its there warm, cold, low rev, high rev. It has happened twice so far. Bob. Edited September 5, 2008 by BOB B (see edit history) Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted September 5, 2008 Share Posted September 5, 2008 Being intermittent, i would be inclined to check the crank angle sensor, especially if the timing belt has been changed, as sometimes the trigger wheel is not refitted correctly, or the sensor itself has been knocked/damaged, or there is a bad connection at the plug. Quote Link to comment Share on other sites More sharing options...
Scooter Posted September 5, 2008 Share Posted September 5, 2008 "chrisavila100" was the guy i was thinking of......there are a few threads with possible causes in. Quote Link to comment Share on other sites More sharing options...
JDModified Posted September 7, 2008 Share Posted September 7, 2008 Plenty of coolant in there??? lack of coolant will play havok with the timing and causes missfires. James Quote Link to comment Share on other sites More sharing options...
bonus_2000 Posted September 8, 2008 Share Posted September 8, 2008 Ive changed the coil pack connector housings when I did the plugs. It doesnt seem to be an intermittant fault it just starts off hardly noticable then just steadilly gets worse over the period. I first notice it at say traffic lights, it just pops every second or so then as time goes I notice it just driving along then aventually a bucket of spanners for a short time then it seems to start biulding again. Sorry forgot to mention Im prity sure its a missfire, sounds as you said tricky and when it starts its there warm, cold, low rev, high rev. It has happened twice so far. Bob. I had a misfire on mine a while back, and I had changed all of the connector clips also. It turned out where I had been taking the plugs in and out, and the wiring harness on the car was about 14 years old (and of course the wiring to the coil packs passes right over the top of the engine), where it had been getting hot and cold for a long time, the shrouding round the cables had all started to crack up and the wires were slowly disintegrating. I cut the section out of the wire and resoldered and it was fine again. You can't really see the state of those cables normally because of the plastic trunking they put round it all from factory. Just something maybe worth checking, because mine used to get worse when it got hot. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 8, 2008 Share Posted September 8, 2008 "chrisavila100" was the guy i was thinking of......there are a few threads with possible causes in. Quote Link to comment Share on other sites More sharing options...
mrdsukautos Posted September 9, 2008 Share Posted September 9, 2008 I had a misfire on mine a while back, and I had changed all of the connector clips also. It turned out where I had been taking the plugs in and out, and the wiring harness on the car was about 14 years old (and of course the wiring to the coil packs passes right over the top of the engine), where it had been getting hot and cold for a long time, the shrouding round the cables had all started to crack up and the wires were slowly disintegrating. I cut the section out of the wire and resoldered and it was fine again. You can't really see the state of those cables normally because of the plastic trunking they put round it all from factory. Just something maybe worth checking, because mine used to get worse when it got hot. Also make sure to open the hard plastic section at front of block I did the same to a car with this same problem misfiring etc and went all the way under the hard plastic and found even more cracked wires there also its a shitty awkward job but well worth the checking Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.