General Cars like a kanagroo

[Signet]

Hi all
I have just bought a MK2 1999 x reg 1.2 punto. Everything was great on the way home then the next day it started acting like a kanagroo at about mid revs and the lights constantly pulse. When i let off the accelerater its even more violent. I have read various threads and so far have changed the coil pack and leads, both lambda sensors, the cat cause it was gone and full exhaust same reason. Even with all these things it hasnt helped and now i'm at a loose end. This car was meant to ne my partners first car but with these problems she wont drive it.

Thanks in advance for your replies

 

[Ziggy122]

Usually a mis-fire is because its not sparking - you get a Judder Not a Kangaroo effect! :|


Do you know which cyclinder its misfiring on?

Does it seem to shake even at idle?


Ziggy

 

[Signet]

Not a clue which one it is. But ye at idle the lights do still flicker and there does appear to be a slight misfire. Never noticed till i just went and had a good listen.

Do you think i should change the plugs aswell or is it a little more serious

 

[Ziggy122]

Lights appear? - you mean the EML light is flashing?

Bad plugs can cause a misfire - get them out and test them

Ziggy

 

[Signet]

No the lights as in the headlights and dash board lights, but not the stereo lights.

I will test the plugs first thing in the morning

 

[JustAndy]

Sorry to thread hijack but how exactly do you test plugs? Mines misfiring and was wondering if it could be the plugs. Is it as simple as taking them out, pushing them back onto the ht leads then hold them against block and crank engine?

 

[Signet]

If you remove the plug, replug on the ht lead and hold the plug against the block, get someone nice to turn the key only a little and as it turns over you should see the spark in the gap of the plug

 

[JustAndy]

If you remove the plug, replug on the ht lead and hold the plug against the block, get someone nice to turn the key only a little and as it turns over you should see the spark in the gap of the plug

Awesome cheers, Im sure i can get someone to come crank the engine for me

 

[wilko92]

Keep a steady foot

 

[Sqwidge]

Or you could run the engine, and using insulated pliers or gloves pull the HT lead off the plugs and refit one at a time, this will cause your motor to run badly until you hit the dodgy spark plug which will have no effect at all.
Its quicker and there is no chance of a noob cross threading the plug.

 

[Signet]

I'm just hoping it is the plugs, else i really am stumped

 

[Ziggy122]

There is usually one of 5 faults

1 - Spark plugs - cheap and cheerful really
They get old / sooty / Corroded and break down over time
Replacing them = eliminates the fault

2 - The HT leads
A good way to test is to open the engine bay up at night (VERY DARK) and 1 person starts car, one stays looking in the enginebay - your looking for blue flash's = HT lead is leaking and earthing instead of going to the Plug

3 - The Coil Pack
Known to fail, the pack fails to send a spark to the plugs
Only way to test is to swap packs - if fault re-occours its not the pack its probably no4 or 5

4 - The Crank Sensor / RPMsensor
The car has to see the Engines speed, if its struggling to see it might have a few sparks and dies / few sparks / dies - anyway make sure its about 5mm i think it is away from the CrankShaft Wheel on the end

5 - the Ecu, again its common but not as common as the Coilpacks failing
There is a track in the ECU that Burns out = One line doesn't get the signal at all
You have 1 of 2 options
A - Get a donor ECU - Keys - Locks - Ign barrell - immbo unit
and eliminate it thatway
b - get it repaired - send it to a specialist

Ziggy

 

[kitchman]

I had a similar problem and it was the alternator

 

[DaveMcT]

Dont forget the big fat battery earth lead is not loose or got dirty contacts.

 

[Signet]

all very good point that i'm gonna go check.

 

[rob1987]

hi sorry to hijack but how have you got on with this? i have similar problem

 

[Trooper1]

If the headlamps are flickering I would guess at it being dodgy alternator wires or bad battery connections or bad earth..Maybe alternator is a bit duff..Check all wires to alternator make sure they are tight and clean and same with battery leads and earth..