Ford Mondeo 2.OO 1994 Missing/Shuddering?

Question

the car is fine on first using but after 1st mile or so when enrichment programme switches of it badly misfires and shudders but only using low foot throttle pressure [when i put my foot down it is o.k ] it also badly 'pinks] during this problem it sometimes improves as car is fully warmed up[4 or 5 miles] i have changed E.C.U +PLUGS AND LEADS AND AIR FLOW METRE AND TEMP GAUGE AND FUEL FILTER

Answer 1

get a diagnostic. that should point you right

Answer 2

I would agree that an air leak is a high possible. To test, run car at idle, and spray some carb cleaner, or wd-40 around the air pipes, intakes etc. If the engine speeds up after a squirt, you know where the leak is...

Also check that the throttle body isn't clogged up. This is the large, normally shiny metal long tube-like item that the throttle cable goes to, so has a revolving spring cam at the side which will move when you or someone else presses the accelerator pedal. The big air pipe that comes from the air filter box goes to this at one end and it normally sits on or near the manifiold. With the engine and ignition off, take off the fixing clip that holds the large rubber pipe and look inside, with a torch if nec. Put your fingers inside and you should be able to feel/see a flap, that moves, is moved by the throttle, accelerator pedal. If this is black, sooty, oily, or just genrally stick gooey, spary and clean using carb cleaner. If dirty you may have to use a whole can...When reassembled, on first starting the vehicle it will take a few more turns to fire up. This is normal. Just turn it over, without using the pedal, then after 10 seconds, if it hasnt fired up, try again but with half-pedal. That should do it, then see the difference

Finally always use a fuel additive in your petrol tank, every 3 to 6,000 miles.

Hope this helps

kardocktor

Answer 3

Hi

This sounds very much like a problem with the O2 sensor. It is ignored until the engine gains a bit of temperature, and also when you put your foot down to accelerate, and in both cases it is because enrichment is required which the O2 sensor would counteract.

It could also be a problem with the coolant temp sensor or the throttle sensor, but I would check the O2 sensor scenario first.

Cheers

Geordie

Answer 4

try replacing the distributer cap as these can crack and let in moisture which can cause any car miss and shudder.

i had the same problem with my escort and when i replaced that the missing and the shuddering disappeared.

plus next time you fill the car up use a 98ron petrol instead of the regular 95ron just to clean some of the crap out the engine!

Answer 5

then theres not much left, but a clogged jet or air leak would cause the problem,

check every pipe thats attached to the engine, its a ford and these air pipes do work free, and crack, sucking in huge ammounts of air... and doing exactly what you describe. oh, itll be close to the inlet manifold... fire the car up, and listen for it...

also check for other air leaks... around the manifold and the air intake... good luck

and its not your timing... the dizzy is set.... and the ignition system is electronic... it will be something simple... it always is.

Answer 6

the valves are sticking in the head contact a ford dealer and tell them,they will say its TSB 24,sticking valves can get costly as you have to change the exh.valves and hyd.tappets.good luck

Answer 7

try premium fuel.... if that still does not work, send it to a car specialist in tuning the engine management system. it sounds to me like it is a timing problem... it may be running too advanced or retarded.

Answer 8

You could have sticky valves. The early zetec engine were notorious for it.

Answer 9

Have you had the dodgy petrol.

Answer 10

have you changed your oxygen sensor?