car jolting/bunnyhopping

[Cakky]

Just started over the last week or so, driving down the road 50-60km/h 4th gear, car will feel like it is jerking/bunnyhopping and when taking off from a stop in low revs crawling along slowly seems to be particularly bad and starts hopping quite badly - quite really when everyones watching you thinking your some learner driver or something.

a friend ( gasman ) had a drive of it last night and he seems to think its most likely an electrical fault, thinking TPS possibly? Also going to try some new plugs because it hasn't had any in a long time and possibly new distributor?

Also for quite a while after the car has got wet or the roads are wet have noticed a small squeaking sound after lifting off throttle, could this be related at all? Maybe a worn mount?

[B1NZ]

Possible engine mount?

[touge_ae101]

what other signs are there that something might not be right? when it bunnyhops is it misfiring or running on 3 or just jerky?

hasn't got a vacuum leak or anything simple like that? also might pay to check timing and make sure its not too far advanced etc.

[Cakky]

just jerky mainly, it does feel slightly down on power really low down - but can't remember if thats normal for a blacktop haha. doesn't seem like its misfiring or a cylinder down, to me it seems like the revs do hunt a bit, but not enough for the amount of jerkyness its got? it's weird.

[touge_ae101]

checking the codes will tell you if any of the sensors are not working but past that i would be looking at both the MAP and TPS sensors and if they have any vacuum leaks going to them.

[sergei]

Leads/Distributor/Plugs/Coil is first thing to check, it sounds like it is misfiring.

[Quint]

+1 for dizzy or tps.

[Cakky]

tried diagnosing but no codes something to do with when we wired the conversion up I think is the reason that doesn't work. will try the tps, sparkplugs etc and see how that goes

[Cakky]

changed the plugs no luck.... going to try swap another coil into it tomorrow, leads look fine - Might need to check if the belts slipped a tooth? It's got me stumped. A mechanic friend will be on hand tomorrow anyway so hopefully come to some sort of conclusion

[gasman]

i got a spare coil and ignitor you can have to try if you want.

[~SlideWays~]

Had same problem with ST ae101, tried everything already mentioned. One last thing I was going to try was opening up the ECU and see if it had leaky capacitors, might be an option for yours?

[sergei]

+1 for the leaky caps.
Have fixed them in mine, but symptoms were slightly different: VVT would engage randomly on idle, the idle would be rough because of that.