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View Full Version : 14NV - Misfire at low revs and wont idle


kent14sr
28-07-13, 07:26 PM
I am at my wits end with the current engine in the Nova.

It will not idle and misfires between 1000 and 1800rpm. It has been like it since before I changed;



Headgasket/Valve Stem Oil Seals/Manifold gaskets
Camshaft changed to AST2 and vernier
Distributor Cap
2E3 changed to one that is "known good" and ran without problem on another car
Plugs/Leads/Waterpump/Cambelt all changed
Compression on all cylinders is fine (between 185-195)
Oil and filter changed
After all of the above it still runs exactly as it did before. It is fine pulling through the rev range, other than at low revs between 1000 and 1800 rpm when it misfires, and stutters. It doesn't smoke, and runs at normal temperature at all times with coolant clean.

I am left to think the only items left are the (Bosch)coil and distributor - rotor arm looks fine and I would assume if its at fault then it would be the same at higher revs.

Initially I was convinced it was an air leak but after changing every possible gasket and checking all hoses/vac pipes (inc brake servo vac) it doesn't seem to be.

Any other ideas!?
therealnovaboy
28-07-13, 07:30 PM
how does it run on the choke?
kent14sr
28-07-13, 07:34 PM
It still wont idle, but runs ok otherwise.
Southie
28-07-13, 07:46 PM
What plugs are you using and are they gapped correctly?

Have you checked your timing and also checked for any air leaks?
kent14sr
28-07-13, 07:49 PM
BPR6ES (NGK)

Its difficult to check the timing as it wont idle although it doesn't pink (etc) further up the rev range.

Checked for all air leaks I can think of (despite changing inlet gasket and carb to manifold gaskets) - but I guess it could be faulty servo (works fine on pedal) or vac advance unit.
greene94
28-07-13, 07:49 PM
have you checked all the vacuum pipes that made mine run rough and it wouldn't idle.
kent14sr
28-07-13, 07:52 PM
Yes and replaced most of them! The lack of idle (I though initially) was indeed due to a vacuum pipe, but all checked and ok!
Southie
28-07-13, 07:56 PM
What cam are you running?
kent14sr
28-07-13, 07:56 PM
Kent AST2
jimbob-mcgrew
28-07-13, 09:02 PM
idle jets not blocked is it ?
Southie
28-07-13, 09:03 PM
Kent AST2

Have the verniers been setup correctly?
kent14sr
28-07-13, 09:05 PM
Is that the one that unscrews from top of carb next to 1st barrel?
meritlover
28-07-13, 09:21 PM
That sounds like an emulsion tube.

Stick a timing light on to see if its a spark or lean miss.

Sounds fuel related
kent14sr
28-07-13, 09:27 PM
That sounds like an emulsion tube.

Stick a timing light on to see if its a spark or lean miss.

Sounds fuel related

I will try that - when you pull away it almost bogs out a bit before it picks up and goes.
meritlover
28-07-13, 09:31 PM
Sounds like a transition jet or as Jim-Bob has correctly suggested, the idle jet.
Do a full methodical strip down and clean out.
marc69
28-07-13, 10:53 PM
idle jets not blocked is it ?

About to say this, try the idle jet from another 2e3, I had to do this with my 1.3
jimbob-mcgrew
29-07-13, 01:19 PM
Is that the one that unscrews from top of carb next to 1st barrel?

yeah that's right, I think its the only one you can pull out without disassembly. the secondary jets are located inside.
its a long and thin brass piece.
it has holes thru its sides, as well as thru its core, sometimes clogs a bit.
make sure you've got a good fitting flathead screwdriver before you take it out, as the brass is soft and easy to mangle if your not carefull.
i'd get a long nozzle on a can of carb cleaner, blast it thru the side holes aswell as the needle core, and poke the long nozzle down into its slot and give the carb a wee blast too before replacing the needle.
might not be the issue, but worth a try, to rule it out.

what colour are the plugs too ?