[Problem] Heavy Jerking at low revs.

[deodorant]

Firstly, I couldn't find any dedicated car problem forum so I hope I'm not posting this in the wrong place.

Anyway I put in an open pod air filter (K&N) in my Savvy not too long ago. Since then, the car has developed a problem of heavy jerking under acceleration in the 1k-3k rpm range, most noticeable in 1st and 2nd gears. 3k+ rpm is fine.

Any ideas what the problem could be? I can D/C the battery to reset the ECU and this eliminates the jerking for ... maybe 30-40 km ... and then the problem gradually comes back.

Sooo, what should be my next course of action? I haven't had the car looked at by any mechanic. Send it to Proton SC? Should I get the Speedworks guys to look at it instead? Or get them to put back my original filter before sending the car to proton sc (you know, for warranty issues)?

 

[prodigy]

You should try to put back the original filter. Even that, i'm surprised air filter change will result in heavy jerking. However for precautionary, its good to put back the original filter and check.

Just FYI, jerking at low RPM revs are normally associated with bad spark plugs or distributor.

 

[rollakid]

You should try to put back the original filter. Even that, i'm surprised air filter change will result in heavy jerking. However for precautionary, its good to put back the original filter and check.

Just FYI, jerking at low RPM revs are normally associated with bad spark plugs or distributor.

should be the hot air too. you see, i recently transplant my car, running open pod filter. When the car is cold and the fan not spining, the car just drive properly without any prob. but if the engine got hot and fan start spining, all the hot air gush in through the radiator and my car will start to jerk. condition even worse if i use aircond (twice the hot air coming into the engine bay + compresor taking engine power).

oh ya, i dun have cold air intake.

 

[deodorant]

Well I have a heat shield installed (don't know how effective it is, though).

I'm guessing this is just a huge coincidence, though, cos upgrading intake/exhaust is *supposed* to be very, very hassle-free. Guess I'll just get my neighbour mechanic to take a look at the car and see if prodigy's diagnosis of spark plug/distributor malfunction is true.

Oh I also found a small article on the intarwebby that low-rpm's jerking can also be caused by leaks in the air intake manifold (I will declare right now that I have no idea wtf this means).

Hopefully it isn't anything more serious than that ;3

 

[rollakid]

make sense, especially if you run on air flow meter. is savvy running on afm?

 

[satria_95]

but if the engine got hot and fan start spining, all the hot air gush in through the radiator and my car will start to jerk. condition even worse if i use aircond (twice the hot air coming into the engine bay + compresor taking engine power).

I thought the fan sucks out hot air from the engine bay, blows it through the radiator and out through the front? Well, that's what I noticed in mine.

 

[rollakid]

I thought the fan sucks out hot air from the engine bay, blows it through the radiator and out through the front? Well, that's what I noticed in mine.

??

suck in ler.. never see any car that sucks out through the front before...