random st.t..st..stutter

J

JamesB

Guest
I have just has a surge tank and bosch 984 pump proffesionally fitted to my r. It was leaning out and detting at 1 bar with the old pump so i took the bleeder off until the fueling was sorted.

Now im just running standard boost with good fueling and on the odd occasion with WOT at 4500 - 5500RPM it will stutter one, two or three times then keep reving fine. No pops, bangs or detting - just a stutter (but more like a cut i think). On one occasion it did it at 3500RPM at maybe 1/2 to 2/3 throttle (it did a small pop then). To give you a better idea, it has happened maybe 5 or 10% of the time I give it WOT (but very random) over the last couple weeks.

The rest of the time the car drives perfectly - although Ive noticed the standard gauge now reads about 6.5 -7 instead of 5 - 5.5 like it used to. I have checked wastegate and boost signal hose - they're ok.

15,000kms ago replaced dizzy cap, all HT leads, dizzy rotor, afm (reground) and coil.

Less than 500kms ago replaced plugs (normal heat range NGK iriway), rocker cover gasket, fuel filter, oil filter, oil (Castrol formula R 10 - 60w), injector cleaner (twice) and always always 98RON fuel.

Have done fault code check - all clear.

I have no idea - please help :? :roll: .

James.
 
A

Anonymous

Guest
What about the o2 sensor? Is it using more fuel than usual?
 
K

KrissJ

Guest
I've got the same problem and its really buggin me cos I don't know what it is.

1 theory is a bad/short to the earth somewhere cos my dash keeps cuitting out as well. It'll send dodgy signals to the ecu now and again and so affect acceleration and general running.
 
A

Anonymous

Guest
check all connections of the HT leads dizzy etc.., check resistance, could be your the ignition is shorting somewhere.
 
J

JamesB

Guest
The guys on the oz forum suggested overfuelling due to the standard fpr not liking the new pump. I will try and check my a/f ratio.

All leads/connections within reasonable access have been checked.

Any other ideas???????
 
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