Sure... Because a cold engine requires a richer mixture than a warm engine. That's because when the engine is cold, fuel drawn into the cylinder condenses on the cylinder walls, effectively leaning out the mixture. That's why the warmup regulator enriches the mixture when the engine is cold and partly why you have a cold start valve. Anyway, if we assume that the fuel filter is partially clogged your car would be running leaner due to impared fuel delivery. It would possibly run okay when warm, but since the car NEEDS a richer mixture when cold, and can't get it due to the clogged filter, the filter coiuld cause symptoms only when cold. If it gets progressivley worse, eventually it would cause problems even when the engine is warm. -Joe Kuchan >From: doctorDHD@xxxxxxx >Reply-To: dmcnews@xxxxxxxxxxxxxxx >To: dmcnews@xxxxxxxxxxxxxxx >Subject: [DML] RE: Strange acceleration problem >Date: Sat, 22 Oct 2005 15:38:38 EDT > > > >Can someone explain to me how a bad fuel filter can cause hesitation and >back firing only when the engine is cold? > > > >Thanks, > >D² & 6530 > >Dan, > >Before you try to trouble shoot the fuel injection I would suggest >changing >the fuel filter. That corrects the symptoms you describe more than half of >the time. Do you know when it was last changed? A bad CPR won't allow you >to >accelerate at all for a few minutes with a cold engine so I doubt it's >that. > >Here is something ponder over. When I start my car after sitting for >the night it starts up fine. When I give it gas to get out of my >driveway and up the street, I notice I lose acceleration. I then here >a slight backfire in about 3-4 quicks pops. After this the car runs >fine and I don't get it again until the next day after sitting >overnight. Any thoughts on the cause of this? Thanks! To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/