Lack of smoothness in motion
03-08-2002, 08:58 AM
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Lack of smoothness in motion
My '90 C$ lacks smoothness in motion while travelling around 2000 rpm in any gear. It happens also during acceleration-release cycles. It doesn't seem to be an engine problem. However I've checked distributor belt (OK) and replaced plugs without results.
Has anyone experienced the same problem ?
Has anyone experienced the same problem ?
03-08-2002, 09:07 AM
#2
Hi,
Mine didn't used to be very smooth at low revs and tended to be a bit jerky, almost as if it was hunting. It disappeared when I had my idle hunting problem fixed. For me, it was due to worn distributor caps / rotor arms.
Dave
90 C4
Mine didn't used to be very smooth at low revs and tended to be a bit jerky, almost as if it was hunting. It disappeared when I had my idle hunting problem fixed. For me, it was due to worn distributor caps / rotor arms.
Dave
90 C4
03-08-2002, 09:22 AM
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Dear Emanuele,
Your description is very subjective. However I would check your 964s records and check when or if the dual mass flywheel was replaced. In fact I would do a complete check of the records searching for all work carried out.
Maybe the first thing to do is a DME reset. Disconnect the negative cable of the battery for 20 minutes. Reconnect, make sure you tighten it up properly. Hop in and start up and go for a drive. Minimum time is 15 minutes and please drive it. Use the full range of rpms in each gear. Do not need to wind it out but drive it. Get it up to speed ine ach gear (autobahn for this). Do not turn the engine off during this period. This will renew your adaptive memory data. See how things go. I do this whenever I feel the 964 is getting tired or I make a change. Like swapping drilled airbox for original or something like this.
It is worth a try but check those records. Does the 964 give you a shudder especially when cold.
Ciao,
Adrian
911C4
Your description is very subjective. However I would check your 964s records and check when or if the dual mass flywheel was replaced. In fact I would do a complete check of the records searching for all work carried out.
Maybe the first thing to do is a DME reset. Disconnect the negative cable of the battery for 20 minutes. Reconnect, make sure you tighten it up properly. Hop in and start up and go for a drive. Minimum time is 15 minutes and please drive it. Use the full range of rpms in each gear. Do not need to wind it out but drive it. Get it up to speed ine ach gear (autobahn for this). Do not turn the engine off during this period. This will renew your adaptive memory data. See how things go. I do this whenever I feel the 964 is getting tired or I make a change. Like swapping drilled airbox for original or something like this.
It is worth a try but check those records. Does the 964 give you a shudder especially when cold.
Ciao,
Adrian
911C4
03-08-2002, 04:13 PM
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As a close-to-graduation student in mechanical engineering I agree with you about dual mass flywheel. I don't exactly know if my car has the orginal DMF or a popular Luk unit. My C4's story is long: it has been in Germany from '90 to '98 and then it was shipped to Italy where it changed three owners. I chose it among a set of four because it had new parts in ( almost ) all weak points ( new distributors, new brakes' booster pump ).
I tend to exclude the engine because when vibrations appear it keeps going well. The only combustion irregularity I experienced is long postcombustion when I accelerate after a drive in traffic but I consider it normal. It's probably hearable only because I've got a TechArt bypass.
Is there a way to check if the flywheel has been changed without removing the engine ?
P.S. Is there a way to buy your latest 964 book from Italy ( Amazon or something similar ) ?
I tend to exclude the engine because when vibrations appear it keeps going well. The only combustion irregularity I experienced is long postcombustion when I accelerate after a drive in traffic but I consider it normal. It's probably hearable only because I've got a TechArt bypass.
Is there a way to check if the flywheel has been changed without removing the engine ?
P.S. Is there a way to buy your latest 964 book from Italy ( Amazon or something similar ) ?