General Stilo 1.4 rpm drop on idle with electrical load

[Nikola357]

Hi, i have problem with my stilo 1.4 16v, on idle rpm is 750 when apply any electrical load rpm drop to 550 and back up to 750, intresting when is ac on and cabin fan working no dips in rpm, so far i clean throttle body and check all pin resistance with multimeter everything ok, change ground cable from battery to chassis and gearbox, battery is healthy, alternator charge on idle 14.4v (whit ac on and cabin fan on 4 dips to 13.4v in this situation no dips on rpm steady 750 when apply power window) voltage regulator on alternator is new. I did detailed clean of fuse box, checked with multiecuscan no error stored no misfire, self learning performed, checked vakum leak on manifold everything look good. What could be the problem, or is this a normal situation?

the video is not mine but the problem is the same

 

[aschiuta]

Hi, i have problem with my stilo 1.4 16v, on idle rpm is 750 when apply any electrical load rpm drop to 550 and back up to 750, intresting when is ac on and cabin fan working no dips in rpm, so far i clean throttle body and check all pin resistance with multimeter everything ok, change ground cable from battery to chassis and gearbox, battery is healthy, alternator charge on idle 14.4v (whit ac on and cabin fan on 4 dips to 13.4v in this situation no dips on rpm steady 750 when apply power window) voltage regulator on alternator is new. I did detailed clean of fuse box, checked with multiecuscan no error stored no misfire, self learning performed, checked vakum leak on manifold everything look good. What could be the problem, or is this a normal situation?

the video is not mine but the problem is the same

Also check and clean the map sensor.

 

[jackwhoo]

Battery?

 

[Nikola357]

Also check and clean the map sensor.

Cleaned map sensor 20k kilometers ago, i check again.

 

[Nikola357]

Battery?

Battery is in good condition 12.6 V

 

[The Panda Nut]

Battery is in good condition 12.6 V

I had similar situation with voltage. It did prove to be the battery. It failed while still reading around 12.6. A single cell short seems to have been the issue. Time will tell. Any drop when charging suggests it may be the issue. With everyting on Fog lights, heated window, air con heater fan on full fullbeam and dip beam our Pandas still maintain 14v so being less isnt quite right. You may have to wait and see. Engine speed drops as a big load is applied but if raied to 1000rpm voltage is good.

 

[Nikola357]

I had similar situation with voltage. It did prove to be the battery. It failed while still reading around 12.6. A single cell short seems to have been the issue. Time will tell. Any drop when charging suggests it may be the issue. With everyting on Fog lights, heated window, air con heater fan on full fullbeam and dip beam our Pandas still maintain 14v so being less isnt quite right. You may have to wait and see. Engine speed drops as a big load is applied but if raied to 1000rpm voltage is good.

I have another battery with 60amp but nothing changes, simptoms is persist. When turn ac on and fan on max and low beam, voltage charging on idle 750rpm is 13.3V, when i put litle gas to 1000rpm voltage is back to 14.2V

 

[aschiuta]

Cleaned map sensor 20k kilometers ago, i check again.

Use spray cleanner for electronic devices and clean the connectors D3, D4 ..... These connectors are under motor side fusebox. Same for ecu connectors.
When you use AC the ECU command 1000 rot/min for engine so it is more power there.
I presume you dismantle the throttle unit from intake manifold and clean it on both sides.

 

[The Panda Nut]

I have another battery with 60amp but nothing changes, simptoms is persist. When turn ac on and fan on max and low beam, voltage charging on idle 750rpm is 13.3V, when i put litle gas to 1000rpm voltage is back to 14.2V

Ah that sounds normal

 

[Nikola357]

Use spray cleanner for electronic devices and clean the connectors D3, D4 ..... These connectors are under motor side fusebox. Same for ecu connectors.
When you use AC the ECU command 1000 rot/min for engine so it is more power there.
I presume you dismantle the throttle unit from intake manifold and clean it on both sides.

Yes i remove throttle body from manifold and detailed clean to look like new, and check tps resistance and actuator resistance all is ok. Perform detailed clean of fuse box with contact cleaner, but not clean connectors D3, D4 and ECU connectors, i plan to check earth C10,C11 and C20 maybe is colerate with rpm drop. I will clean connectors like you recommended.

 

[Mike1alike]

Possibly the coil packs. What's their state? How old in use?

 

[Nikola357]

Possibly the coil packs. What's their state? How old in use?

For last 60k kilometers since I have owned the car, I have changed 3 out of 4 coils, all of them are from different manufacturers(two of them ngk, one valeo and one original champion factory installation). I changed twice spark plugs on every 30k kilometers, on multiecuscan for my ecu no parameters for coils, but not stores any missfires, and no poping sound from exhaust.

 

[Mike1alike]

I recommend to put new ones, all of them from the same manufacturer, the original Champion factory installation one.
I used on my Punto NGK coils, made in China. I thought they were good and they were, at first. But they started stop working properly way too soon, in about 1 year. And that manifested exactly like your problem, plus some random misfire if I drove on high speed on the highway, like 130km/h.
Replaced them with new original manufacturer Champion which oddly comes under Magneti Marelli name, but that's only on the box. On the coils they have MM stickers, but underneath it's written Champion.
That made it all better, putting new original manufacturer coils. It does make a difference.