Crossflow 1.7 Westfield cylinder 4 misfire

[Buckles]

Hi folks

I have inherited and a Westfield with an old Crossflow engine 1.6 and been advised it’s from and 1980 escort mk2 .. I’m not that technical however have learnt lots over that last few weeks with the help of wscc forum.

Having issues with cylinder #4 misfire and can’t get to the bottom of it so would like to see what advice I could get on here.

Originally it had been set up with wrong firing on the distributor.. it was 1234 instead of 1243 .. at this point it only fired on 1,2 and when altered it fired on 1 2 3 and 4 was not firing..

Checked sparks all ok
Checked sparks all sparked all ok
Changed leads
Checked carb jets all clean and fuel getting through
Butterflies on #4 was closed while on idle however opens fine during throttle
Rocker box off and values don’t seem to be sticking
Compression test on Cylinder 4 was 140 and others around 148
Removing lead from spark while running makes no difference to engine
Exhaust from cylinder 4 does heat up while running

Really stuck with what to do next and would be great to get any ideas that might be causing this or someone that might have seen this before ???

[Auntieroll]

Change the distributor cap, they sometimes develop shorts to earth inside the moulding, (very rare but spent ages fault finding a RV8 which developed similar symptoms in a nearly new OE cap ).
Check the plug sparks when tested outside the engine .

[Buckles]

Yeah tested sparks out of engine and they all sparked.. ??

[GreenV8S]

Is the plug coming out wet or dry on that cylinder?

[finlo]

Have you replaced the plugs? As they can spark ok when out but poorly under compression.

[Auntieroll]

Inlet air leak somewhere ,gasket or manifold ?
If its got a good healthy HT system which sparks under pressure then the problem must lie outside the cylinder, can't be on the exhaust side , must be on the inlet side .

[Buckles]

Sorry for the delay

Ok give u all an update on what’s happening

Cleaned out carb (twin Weber’s ) for cylinder 3 and 4 ... and when replaced the fault seemed to move to cylinder 1

Really confused

Cleaned second carb the exact same but no difference..

Plug is dry and black and been changed for new with no difference

Really struggling to find a solution to this ??

[Buckles]

Also changed distributor cap, rotor and coil .. checked fuel ok and carbs are getting fuel ok

Also changed misabs and dobins to make sure sealed to manifold

[gordmac]

Have you checked the carb balance? Listen to each choke in turn using a tube in your ear and balance them with the screw between the carbs until they sound the same.
Check none of the idle mixture screws are shut.

[Buckles]

Yeah have a carb gauge and they are balanced fine..

Adjusting the air fuel screw makes no difference on cylinder 1 until it’s shut fully and only a very slight change to idle.. as if it’s firing but just and no more.. when accelerating with load engine pretty much cuts out

Only other thing I checked was grounding on engine and was 0.00 but ground wire from electric ignition from distributor was 0.05 .. would this make a difference ??

[Athlon]

Valve gaps..

[Buckles]

Not sure what u mean by value gaps .. I’m a newbie to all this lol how do I check this ?

Find it strange that it worked fine on cylinders 1 2 3 and 4 was faulty but now 2 3 4 work and 1 faulty ??

[Athlon]

Buy a Haynes manual on Ford Escorts and have a read, if you don't understand valve gaps you ain't gonna get a Xflow on Webers working right.

[RLK500]

If the plug is bone dy then I woud say there is no fuel getting to it.Have you drained the tank, and put in fresh fuel and cleaned all of the jets, float chambers etc in the carbs ? I stopped running my webbere'd escort on normal 95 Ron, now use Esso Super which is supposed to be ethanol free and more carb friendly. I had a very similar issue a while back after it had stood for a couple of months. Have also had all plugs sparking but one down when under compression.

[Buckles]

I now have a copy of Haynes escort so will have a read through valve gaps lol

I’ve cleaned out all the jets and checked and adjusted floats to make sure everything ok .. fuel has been replaced and used the super stuff as well so no old fuel should be left in system by now .. the carb was working ok for cylinders 1 2 and 3 but not 4 and as soon as I cleaned out the rear carb cylinder one developed the fault and the rest where fine.. fuel deffo seems to be getting to engine .. covering the intake a little using my hand makes no difference to engine like other intakes but fuel is present in intake when removing my hand .. so fuel deffo being sucked in through the carb ..

What symptoms where u getting and what resolved the issue ?

[Auntieroll]

Buckles said:

Also changed distributor cap, rotor and coil .. checked fuel ok and carbs are getting fuel ok

Also changed misabs and dobins to make sure sealed to manifold

Did you check the inlet manifold to cylinder head gasket is OK?

[RLK500]

I had the same symptoms. One cylinder down, seem to remember that I stripped everything I could out of the carbs, accelerator pump, jets, floats, replaced all the gaskets/seals the lot. Once that old ste petrol is in there it's nasty. Just a thought have you got any quickstart ? worth trying that in the cylinder that is down to see if it fires normally for a few seconds, that way you should know if it is petrol or spark.

[Buckles]

Ok need to make sure I’m doing right thing here ..

Checking value gaps and all over the place at the moment .. so I checked them using rule of 9 and noted down what they all currently sitting at the moment using feeler gauge

Valve 1 .019 ex
Valve 2 010 inlet
Valve 3. 011 inlet
Valve 4. 020 ex
Valve 5. 012 ex
Valve 6. 012 inlet
Valve 7 009 inlet
Valve 8. 021 ex

Is the above with regards to which are exhaust valves

And was hoping it would be obvious to see if any where out a little .. I’m seeing that most people suggest 22 for inlets and 24 for exhausts .. which is way out with what I got ??

Any advice welcome

[xtruss]

I maybe chucking a spanner in the works here, but if the engine has a pair of twin webers hanging off it, then i would guess it may also have a performance camshaft fitted rather than standard.
Some performance cams use different valve clearances. E.G a piper 285 which i have used back in the day has 8 thou inlet 10 thou exhaust

[Athlon]

Looks like it has been set up for 12" in, 22" out? Set the gaps with the engine HOT.

If it has a cam in there they will be very different so you need to try and find out if you can.