Random rev drops when accelerating (260z)

[ritchie]

Hi all,

 

Bit of a problem with my auto 260z.  When I push down the accelerator, especially under load (i.e. not in neutral), the revs will move up but then soon after drop down, even with the same pressure on the accelerator pedal.  Even pushing the pedal to the ground is often not generating a response from the engine, it just coasts along at 15 km/h, around 2,000 revs.

 

If it gets any speed, it will "bog down" at random times... every 5 or 6 seconds... where the revs just drop of their own accord. I don't think it's a transmission problem as the same thing happens in when I select second gear.  In neutral/idle it seems fine - or at least a whole lot better.

 

We first thought it was an ignition problem, so did the basics of replacing the spark plugs and the fuel filter. Problem is still there though. The ignition leads look in good nick, and there's no obvious issues with the distributor.

 

Our next possible culprit is the carbies. Trouble is, neither my mate or I have much experience with them. 

 

Anyone had a similar experience before?  Or know common issues with the original 260z Hitachi carbies that we should particular look out for when we take em out and inspect tomorrow?

 

Any help would be appreciated...

 

Cheers guys,

 

Ritchie

[aegean]

Borrow a coil and try that. Could be breaking down.