missfire under aceleration

[mikchim]

hi can anyone shed anylight on a problem with my chimera 400 under hard acceleration in my chim 400 it appears to missfire/hesitate when about half throtle but sometimes will drive threw it if sink foot to the floor. doesent appear to make any diffrence what gear your in. any pointers in the right direction much appreciated.
thanks
mik

[hut49]

Could be plenty of things for sure, but start with the simple things first. If you run the engine in the dark can you see any sparks jumping off the plug lead extensions? They may need replacing. Or any evidence of carbon deposits where they are close to the exhaust? When were the HT leads last replaced? Did you check the rotor arm / distributor cover for signs of cracks? Take the coil off and give it a shake - if it sounds/feels like there's fluid in there it's past its sell by date.

[mowog]

Lots of threads on here recently relating to hesistation/misfiring/lumpiness.

I had similar issues recently until I replaced virtually all the ignition/HT bits that looked past their best. Coil/Dizzy Cap/Rotor Arm/Plugs/HT Leads and don't forget the plug extenders!! Don't know which bits were to blame but everything is smooth again (all genuine lucas parts less than £100 including the ACT plug extenders www.actproducts.co.uk - pulls smoothly in any gear from 1200rpn. no hesitation and a more stable idle.

Good luck!

D

>> Edited by mowog on Wednesday 28th December 15:50

>> Edited by mowog on Wednesday 28th December 15:50

[dodgyviper]

could also be engine mounts (had this myself)

[Cider Andy]

Have a look at the throttle pot. Test it with a multimeter, or better still an oscilloscope, as it won't necessarily show up on the multimeter.

[Nick_Chim]

How much fuel is in your tank? When mine gets below 1/4 tank, it often doesn't respond to full throttle deflection - particularly if you've been having fun & foaming up the fuel!

Hope it's as simple as that!

[colinrob]

Had thesame on mine chaged plug extenders everything then fine

[blujay10]

colinrob said:

Had thesame on mine chaged plug extenders everything then fine

Me too! Sorted mine out with new leads, extenders and plugs as well. may be worth checking your plugs as they get mucky pretty quickly if running a bit rough.