Missing very intermittently on idle, but generally idles ok.have replaced leads spark plugs and checked distributor cap

Well, since the spark to #2 comes from the distributor, and the others are firing, could be a bad plug wire or sparkplug. Also make sure there isnt anything down around the sparkplug that could be shorting out. I would go ahead with new plug wires for starters, as that usually gets replaced when you do the distributor and rotor. Inspect plugs too- they may need replacing.

Check the following items:
- Check the spark plug gaps. (0.90 - 1.0 mm)
- Check the resistance of spark plug high tension cords (10 K Ohms - 25 K Ohms)
- Check the distributor cap and rotor for cracks and or corrosion.
- Check ignition timing (17 degrees at 750 rpm)

Check for plug leads touching each other. Check for moisture in distributor cap if you have one. Check plugs and replace if necesary

1. Replace your spark plug wires.
2. Check and replace your spark plugs.
3. If you have a Check Engine Light on, have the codes checked.
   
4. Check the timing.
5. Check and replace the Distributor Cap and Rotor.
6. Check the fuel pressure.
7. Check the fuel pressure regulator.
8. Check the fuel injectors.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

Replace the spark plugs, spark plug wires, distributor cap, and rotor. Next, check the idle air control valve and replace it if found faulty. If it still shakes, have the timing checked out

Misfiring Escort...
THE Guide!
1- check HT leads, including the main lead from the coil. pull one off at a time and see if there is any difference in engine noise, if a lead makes no difference to the engine note when you pull it off it is broken and you need a new lead for that plug - best to replace a full set since the others will be on their way out too. try each plug and check the leads like this with the engine running, 2- clean/repace distributor cap and rotor arm if it is dirty or corroded, there are 2 Clips, one on either side of the distributor cap, pull em off, take the distributor cap off, look inside the cap, there are 4 pins, are they all corroded and covered in white stuff?, they should be shiny brass, clean them up with fine wet and dry sandpaper, make them flat and shiny again. also still on the distributor is the rotor arm, pull it off, it may need a bit of wiggling - clean this up the same with the wet and dry, get a very fine grade of wet and dry sandpaper since you want the metal to be as smooth as possible afterwards, once the cap and rotor both have shiny metal clean them with mild detergent, rinse and dry them fully, not only to clean them of dirt and grime but also the metal filings from the sanding are "bad" for the distributor.. once dried refit the rotor arm (it only goes on one way, do not force it) refit the distributor cap, make sure its the right way round (make a note of its position BEFORE you remove it) 3- check if air filter is blocked and replace it if it is very dirty - if you think it is blocked try running the engine without the filter and see if it runs better, you know for sure you have a bad filter if this is the case. 4- check fuel filter (especially on 1.0 and 1.3 engines) for blockage and fuel line for blockage (replacement costs £3.50-£5 or so)
apart from that its "experience required" jobs like setting the ignition timing - just get a normal tune up after you've checked out the leads and dizzy/rotor arm which is quite cheap on an escort, you only turn the dizzy and move 1 screw...
Just for reference in case i have misjudged you're ability and you want to try tune it yourself... 1989 MK4 Ford Escort ;-D you didn't give CC so you'll get all engine data for 1989! (petrol)
NOTE: the CVH engines have hydraulic tappets so no adjustment is possible and no data is given. ---------------------------------------------
Escort 1.3 "HCS" 1988-1990 1297cc Valve tappet clearances - Inlet --- 0.20mm - Exhaust 0.32mm Firing order 1-2-4-3 Idle speed - 700-800RPM -
750RPM is optimal idle but anything between 700-800RMP is acceptable.
Ignition Timing- 15 Degrees before top dead center at idle RPM
Spark Plugs : Motorcraft - AGRF22 Champion - RS9YC Spark Plug Gap - 1.00mm (check it is right or it will misfire...)
---------------------------------------------------------------------
Escort 1.4 (1392cc) "CVH" - 1986-1990
Firing Order 1-3-4-2 Idle speed 750-850RPM, 800 being optimum _____ NOTE: This engine requires premium fuel (97 Ron) or it will run poorly - damage may result from using low grade fuel. ----------------------------
Ignition Timing - 12 degrees BTDC at idle RPM. Spark plugs - Motorcraft - AGPR22C Champion - RC7YC Spark plug gap 0.75mm (check this)

----------------------------------------------------------
Escort 1.4i Catalyst - 1.4 "CVH" 1392cc 1989-1990
Idle RPM 850-950RPM 900RPM Being optimum :This engine needs only regular unledad 95RON
Ignition timing - 8 to 12 degrees BTDC 10 degrees being optimum Spark PLugs - Motorcraft - AGPR22C1 Champion - RC7YC
---------------------------------------------------------------------------
Ford Escort 1.6 "CVH" 1596CC
Firing order 1-3-4-2 Idle speed - 750-850RPM - 800 being optimal Ignition Timing - 12 degrees BTDC at 800 RPM Spark Plugs - Motorcraft - AGPR22C Champion - RC7YC Spark Plug Gap - 0.75mm (check it!)
NOTE :This engine will run on regular fuel (95 RON) but the timing should be set to 8 Degrees BTDC at idle RPM for this fuel.
------------------------------------------------------------
FORD ESCORT 1.1 - 1989-1990 - 1118cc "HCS"
Firing order 1-2-4-3
Idle speed - 700-800RPM 750 Being optimal
This engine runs on regular or premium fuel without adjustment
Ignition Timing - 10 degrees BTDC
Spark Plugs - Motorcraft - AGRF22C1 Champion - RS9YC Spark Plug Gap 1.00mm (check this!)
-------------------------------------
So check your spark plug gaps with feeler guages if you don't have a feeler guage they're less than a fiver at a cheap motor shop - even pound shop and market stalls sometimes have them.
Apart from that lot - these cars can run bad if the battery is weak, they chug like hell on a half charged or failing battery, so make sure the battery is strong too...
The carburettor jets could be clogged or worn... Inlet manifold could be leaking?
Check the low tension wiring (the wiring on the ignition coil, the two round plugs that puch onto the coil) one red and one green/black/stripey/somethin - trace these two wires around the engine bay and check them for damage and loose connections.
Thats all I can think of right now tell me how you get on, I KNOW these cars... I'll go step by step if you need help checking everything/replacing whats wrong,
------------------------------
Good luck.

Check and make sure your distributor cap and rotor are not corroded and gunked up. If a spark plug is ever dropped, the center electrode could be cracked leading to a improperly firing spark plug (causing a misfire). parts get dropped during shipping all the time.

good luck!

You can have car put on scope and it wll show any irregularities in the ignition system. It can also be dowithout any equipment. First, loosing ALL 8 spark plug wires, Now place the spark plug wires loosly back on, just secure enough to secure. You might need 2 people. Being the miss is more consistant in gear, APPLY THE EMERGENCY BRAKE , put trans into drive and raise rpm's till miss is obvious. Remove ONE plug wire at a time, TILL THERE IS NO DIFFERENCE IN MISS. Thats the cylinder missing. Start with the spark plug, inspect, work back to wires and cap. An EXTREME result will be NO COMPRESSION.

Get the codes read. Auto Zone will check your codes for FREE.

vacuum leak bad pcv if engine shake at idle but goes good when you give gas check that out hope it FIXYA our problem thanks pierre