TB42E Rough idle

[Jimbo]

My 1994 gq TB42E has had a miss while it idles since i bought it 2 years ago.

It idles exactly the same on petrol and LPG. It doesn't worry me much but i thought i would just ask around if anyone else has had similar problems.

Leads and rotor cap seem fine and the previous owner put iridium plugs in it when he put a new head on it 40,000km ago. Patrol goes really well otherwise and revs out cleanly.

Cheers


Jimmy

[tj81]

Would almost bet its electrical.

You dont mention if its carby or EFI, being a 94 id almost bet EFI.

If not, id be changeing the points and the condensor, checking the ballast resistor (for the price of em, hell change it too) and coil output.

Dwell angle, timing and vaccuum leaks.

EFI - check everything electrical. Run a bottle of injector cleaner through, check for vaccuum leaks also

[MyGQ]

while he didn't say if its EFI or Carby directly, he did say TB42E which is the EFI model, TB42 or TB42S is the carby

Most likley electrical or the computer not timing it right, most TB42 engines have a bit of a miss at idle.

[tj81]

doesnt matter

[Jimbo]

Yes its EFI. I have run carby cleaner through it and also chnged the AFM a while back (for other reasons).

This miss only happens at idle and it runs great everywhere else. It also has extracters if that helps.

[TUFF MAV]

Check the valve clearances

Kyle

[Jimbo]

Ahh yeah and the valves were done a few thousand km ago to the same speck as my mates carbi shorty and his idles very smooth.

How can you tell if you need a new dissy cap? I pulled mine off the other week and cleaned a bit of crap off the contacts and made no difference.

Thanks for the replies

Jimmy