Second and Third plug not firing

[Asiangunner]

Hi guys,

Once again the wife hinted that maybe i should sell the Lux and as per everytime she brings it up the car has a habit of hearing her and has broken down.

Cars been running great and after a ten min drive to the dump i turned it off then went to start it up and all of a sudden there was only 100-200rpm on idle.

Car struggles to rev and barely gets above 1000 rpm.

The whole ignition system has recently been renewed over the past year, leads, cap, rotor arm, coil have all been changed.

Whilst at the road side I checked the ignition leads and it seems 2 and 3 are now firing at all.

I then got my bro to quick buy replacement spark plugs and he brought them down. Changed 2 and 3 quickly and it made no difference.

I could really use number 4 to check 2 and 3 as only number 1 was left running and number 1 lead could not reach 2 and 3.

The leads are only about 6 months old and are decent magnecor ones, i can't believe that both of them would fail at the same time with no warning.

I have an old set of 1,2 and 4 leads which im going to take to the car tomorrow, i had to leave it parked up 3 miles away :-(

What else could be causing this issue guys? any advice??

 

[Asiangunner]

Just to add, when trying to rev the car is gradually gets up to about 1500 rpm but there are popping banging noises which i assume is un burnt fuel.

There are no rotational banging or knocking noises coming from the engine block

 

[944 man]

Ignition amplifier?

 

[vitesse]

Are the leads properly inserted in to the dizzy cap?

 

[ChasR]

Where in the country are you? I have an ignition tester which can conclusively rule out an ignition issue. However, it may suggest something more sinister...

 

[Asiangunner]

I'm in SE London mate.

Plugs are in securely at cap.

What's the ignition amplifier? How can I check it mate?

 

[Asiangunner]

Update

Just got to the car this morning and fired it up, it started normally and didn't misfire

I managed to get 1 mile down the road and it's misfiring on two and three again...

Help please?!?

 

[TTM]

Are all 4 plugs the same colour?

 

[Asiangunner]

Hi mate, just waiting for recovery

I've changed all the plugs now at the roadside

2-3 are different coloring to 1&4

I'll try upload pics now, 2&3 are not burnt, they have a bit of a red/brown colour

1&4 are black, which I believe is normal

 

[vitesse]

Well it sounds to me like any or a mixture of:-
Plugs
Leads
Distributor cap

despite perhaps them having been renewed/investigated,whatever.

 

[Asiangunner]

I've pulled the cap off and there are no unusual marks or signs of wear, it's about a year old.

The leads are virtually brand new and the plugs are new now, still got the same issue

 

[TTM]

If it starts fine when it's cold then it could be the blue coolant temp sensor on the block, can mess up the fuel delivery and turn the plugs black by overfueling.
Plugs should be beige/grey, but black means running pig rich.

 

[Asiangunner]

Heres the pics of the plugs, 2 and three are the middle ones

[/URL][/IMG]

[/URL][/IMG]

[/URL][/IMG]

[/URL][/IMG]

 

[Asiangunner]

ORIGINAL: TTM

If it starts fine when it's cold then it could be the blue coolant temp sensor on the block, can mess up the fuel delivery and turn the plugs black by overfueling.
Plugs should be beige/grey, but black means running pig rich.

Would that cause the car to misfire this badly mate? The coolant sensor is only about 2 years old, I changed it when my head gasket went a couple of years ago.

 

[JamesO]

A timing light, fairly cheap will tell you if you are getting spark at the plug leads.

On the 8 valve cars the injectors are fired in pairs using two circuits, it could be as a wild stab in the dark( and possibly completely wrong) a failing injector driver holding two injectors open too long causing over fuelling on those cylinders.

There is no separate ignition amplifier on an 83 car, as far as I'm aware it's ECU, Coil then distributer.



Actually 3 out of the 4 look very black, (my screen is crap). So maybe not.

 

[Mike_Pollock]

Red -Very rich - when my FPR went they were ALL like this
Blue - bit rich
Green - ok

I would remove all plugs, then get the green one and use it to check the spark on each lead in turn.

I suspect fuel / injector problem as it appears to have dried out overnight, then fouled up when turned on again.

Possibly injector leads cracked - wiggle them with the fuel rail cover off. (Courtesy Tony!)

 

[Frenchy]

I suspect the temp sensor (blue plug) i also changed mine last year but it appears to be the problem with my 86 car once warmed up, fine when cold. your plugs are showing rich running, the green circled plug looks correct if not a little rich, they should be "biscuit brown" in colour.
Could also be FPR or AFM, certainly looks like fueling and not ignition.

 

[Asiangunner]

Thanks for the replies Mike and Frenchy.

I've got the car home now and will check it out tomorrow, sods law that i've got the MOT and tax due at the end of the month too, seriously bad timing.

Mike, whats the best way to check the plugs? I've put 4 new plugs in now.

Frenchy, the FPR was changed last year. Is the AFM a Air Flow Meter?

 

[tref]

If you now have a full spare set of plugs I would pull the leads and fit the plugs back into the leads with the plugs earthing on the cam cover. Leave the new plugs in the engine as they should be, and spin it over a couple of turns watching to ensure all four plugs spark as they should. For a couple of turns the unburnt fuel won't do any damage (don't wind it over and over - you just need to prove all four plugs are firing), and it saves having to find a way of isolating the injectors without killing the spark (as pulling the DME relay would). This will at least tell you all four plugs are sparking as they should. that being the case, I would agree with the others it looks like 2-3 out of the four cylinders are running rather rich.

 

[Frenchy]

Yes AFM = Air Flow Meter, when teting the plugs hold them with some insulated pliers or similar against an earth point (cam cover) as they can give you a nasty jolt []