VT Commodore V6 Auto engine miss.

[B J]

I have a VT Commodore V6 Auto that has a miss between around 60 k's 80 k's. It occurs when not accelerating just cruising along. If you accelerate there is also a slight dead spot before it takes off. Other than this, heaps of power - no problems accelerating.

Any tips would be greatly appretiated.
I have changed the plugs, leads, coils. Cleaned throttle body, air cleaner and air sensors. Put a bottle of good quality fuel system cleaner in through the last tank of fuel. No improvement what so ever.

Cheers
Brian

 

[greenacc]

Might be time to look at the trans then. If you drive with the shifter in 3rd does the problem disappear?

 

[devilly]

without starting the car what does the accelerator pedal feel like.does it just flow to the ground or is there some resists ?

 

[B J]

Cheers for the advice. Saw on some other posts to un-plug the cam sensor a few times. Make sure its got a good connection. So did that. Plug and connection is clean. The slight dead spot before take off seems to have gone but can report that the mis is very prominent at 1 1/2 RMP if I hold it there in any gear. Did 1st, 2nd & 3rd. Is there at 1 1/2 RMP. So I'm thinking to put in a new cam sensor. Engine has only just clocked 180,000 k's. Not bad for a 1998 model.. Will let you know how that goes.

Cheers
Brian

 

[devilly]

nice find with the cam angle sensor.i replaced mine with genuine.still when you say 1.5 rpms makes me think it may be the iac or tps sensor playing up a bit.you can clean the iac and see if it changes anything.or check the connectors at these places.

i found by replacing the tps with a genuine one made my pedal looser and stopped a heap of problems.

does it start first turn of the key ?

 

[B J]

yeah starts first turn no prob. Idles is smooth. Accelerator pedal is doesn't have any resistance.

 

[devilly]

maybe have a listen to your injectors with a long screwdriver.if its got a slight blockage it may be more noticeable at higher speeds.even thinking of fuel filter blockage here.

 

[B J]

Well its got me beat. She's going in to Holden tomorrow for diagnostics. Going to spend $160 for them to hopefully tell me whats wrong. Replaced fuel filter, plugs, leads, ignition coil, oxygen sensor, cam sensor, idle air control sensor. Clean the throttle body, mass air sensor, air cleaner and no change. Maybe more wiser tomorrow.