Slight mis-fire
Discussion
I have a slight mis fire. Most noticable on constant throttle 20 to 40 mph, it can be noticed more in 2nd or 3rd gear 1,500/2,500 ish rpm, again on constant throttle...
Options, I think are:
Rotor arm/cap..........both newish and look good
Coil...................Looks ok & no leaks
Air flow meter wires...very brittle, 2 of the insulations are cracked (will tape up & try again)
My favoutite is LT side of the coil wiring/possibly the two black connectors/resistors or whatever they are!!
Any ideas welcome
Options, I think are:
Rotor arm/cap..........both newish and look good
Coil...................Looks ok & no leaks
Air flow meter wires...very brittle, 2 of the insulations are cracked (will tape up & try again)
My favoutite is LT side of the coil wiring/possibly the two black connectors/resistors or whatever they are!!
Any ideas welcome
BliarOut said:
Seasider said:
touching cloth said:
Sell up and buy a Cerb
No, its ok thanks, i enjoy getting to my destination with my car still working
A Porsche then?
Have you checked the HT leads?
Yes
Hughesie II said:
Nothing constructive as usual
Not suprising people complain about sensible threads getting
trashed when Mods get involved as well is it
You seem certain that it is an ignition problem. Could it be fuel related?
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
talkwrench said:
You seem certain that it is an ignition problem. Could it be fuel related?
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
At last
thanks Michael I’ve changed out one suspect lead, don’t really know how to describe but it feels electrical rather than fuel
Seasider said:
talkwrench said:
You seem certain that it is an ignition problem. Could it be fuel related?
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
At last
thanks Michael I’ve changed out one suspect lead, don’t really know how to describe but it feels electrical rather than fuel
Ahem, and what was my first suggestion? Apart from buy a Porsche, obviously!
Anyway, must dash, I've got a blue rinse on the go.
Seasider said:
talkwrench said:
You seem certain that it is an ignition problem. Could it be fuel related?
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
If the misfire is quite 'hard' and noticeable then it probably is ignition. Check the HT leads for general condition and any signs of crossfiring between leads. These RV8's are very lead sensitive.
If the misfire is 'softer' and more of a light hesitation, then I'd suspect fuel - maybe a pressure regulator or even a sticky injector.
At last
thanks Michael I’ve changed out one suspect lead, don’t really know how to describe but it feels electrical rather than fuel
On the subject of how it feels, a problem with the LT side of the ignition rarely causes a 'slight' misfire. It is usually a very noticeable misfire with the possible exception of a faulty hall sensor in the distriibutor.
I'd still suspect the HT side. Assuming your plugs are ok, check HT leads then dist cap then rotor arm then coil. However, coils usually show faults under load and at higher revs.
Edited by talkwrench on Monday 23 April 15:01
talkwrench said:
On the subject of how it feels, a problem with the LT side of the ignition rarely causes a 'slight' misfire. It is usually a very noticeable misfire with the possible exception of a faulty hall sensor in the distriibutor.
I'd still suspect the HT side. Assuming your plugs are ok, check leads then dist cap then rotor arm then coil. However, coild usually show faults under load and at higher revs.
Thats why I’m a bit lost on this one

Gassing Station | General TVR Stuff & Gossip | Top of Page | What's New | My Stuff








A slight mis-fire 