Hesitation when fans kick in

[pete]

Hi All,

Over the past couple of months I've noticed that my '97 Griff 500 tends to hesitate momentarily as the radiator fans start up. In normal driving it's not really noticeable, but it's quite pronounced when chugging along in a traffic jam.

Is this normal? I've had the car 5 years, but I can't remember it doing this until recently. The battery is relatively new, as are the Magnecore leads and distributor cap, and I don't seem to have any other electrical or charging related problems. Could it be ignition related? Coil or ignition amp on the way out or something?

Thanks,
Pete

[Guillotine]

its the heavey load of the fans coming on, dropping the 12v and affecting the ignition.
not badly, or it'll stall.
could be an earth to the fans getting dirty (under rad) or the charging is a touch low or even the battery not being the right spec!

my bet would be the earth.

my 94 500 has done this since i bouhgt it 5 years ago.

but as it only has a 66amp alternator i'm not too worried (MUST get around to uprating, 99amp available)
been meaning to for 4 years

cheers

andy

[joospeed]

A griff that I know well had this problem, I fitted the big capacity Varta battery that I normally reserve for teh cerberas and it's almost totally cured ..

the fans draw a massive current when they first start up ..

I'd wager that if you fitted a bigger battery, cleaned all teh electrical terminals up and fitted dave beer's half speed fan kit you'd never have another problem ..

[Toffer]

I had something similar when my Griff's battery was reaching the end of it's life. The new battery cured everything!

[pete]

Wow - thanks for the quick response. I'll try cleaning the earth connection first, as it's free!

[loose cannon]

my 1995 griff does this to
i have noticed that driving at night with heater and stereo in operation the car jerks around more when the throttle is slightly open you can almost feel it straghning for more battery power, not sure what rating alternator my car has, i will have to have a gander

[red griff 500]

My '94 500 has always done this. I cleaned the earth (which incidentally is a right b*****d to get a spanner onto) and it made no difference.

My suspicion is that it is the massive current surge already mentioned which affects certain sensor/ECU voltage levels which momentarily change the ECU fuelling output. I would have thought that if the voltage dip affected the ignition, then you may experience a misfire rather than the slight dip in revs???

I dunno

[loose cannon]

my alternator is a magnet marelli type a127-65
which im guessing is a 65amp
it was replaced 1998