16 replies to this topic

[Jools Alison]

Hi all, I've just joined, and am seeking some assistance please.

I own a Ford Mondeo 1998 2.0L Petrol Zetec: I had to change the battery on my mondeo the other week (my own fault for leaving the interior light on!), had had no problems previously with the car, but since changing the battery I have noticed that intermittently when accelerating that it feels as though the power is blocked for a few seconds, then burst back through. Today though at low speed the car lost all acceleration (did not stall though) and then sprang back in to life after a few blasts on the throttle. Need to get this fixed, but need to know what is causing it as can't afford a large "diagnosis" fee. Having looked at other threads partially relating to this I noticed comments re: HT leads, plugs and coil pack, or timing belt, or split hoses, catalytic converter. As an aside, my exhaust gases have been usual but plentiful and continue to emit during my 90 mile daily round trip in the cold weather - which I assume means vapor getting burnt off. Any advice would be most welcome. Thanks. Jools.

[Hearsepilot]

It may just need some more ECU training. WHat it needs is a hour or so Sunday driving to teach the ECU some parameters.

Failing that! Take it to a local wide open A or M road. Bat the red needle marked RPM around its end stop until its ears bleed or it falls unconsious.

That'l teach the fekker!

[Jools Alison]

Hearsepilot, on 07 January 2011 - 09:06 PM, said:

It may just need some more ECU training. WHat it needs is a hour or so Sunday driving to teach the ECU some parameters.

Failing that! Take it to a local wide open A or M road. Bat the red needle marked RPM around its end stop until its ears bleed or it falls unconsious.

That'l teach the fekker!

Thanks! I did think that perhaps the ECU would need to relearn itself - and hopefully that will do the trick. My concern I suppose is that whilst this issue has only arisen since the change of battery 10 days ago, whilst I felt "safe" that the odd resistance to throttle would blow itself through, the loss of acceleration whilst going very slowly (i.e. no throttle response) until a few heavy right footers eventually fired the gas through has made me wary of it being one or more of the following:

1. Cat failure - meaning engine gasses not passing through and the blow back in to the engine is what causes the stutter and loss of power
2. Coil Pack / HT Leads / Spark Plugs / Timing Belt - misfire on a cylinder causing the spark to fail
3. Lamba or O2 sensor getting bad message caused by CAT - hence exhaust fumes visible throughout journeys (heavier when in traffic - but standard smoke - not coloured or cloudy)
4. May be a simple split hose somewhere.

One thing I did notice - when I got home after a 115 mile journey on Xmas Day - the next morning there were loads of icicles hanging under the front bumper - directly below the front right headlight - i.e. area where water pump and screen wash fluid are. I may just be being paranoid though - but the icicles were very white (hence thought being escape of washer fluid). That's also when I realised I'd left the interior light on all the noght before hence flat battery, and need to walk 1.5 miles to get new battery!

Problem is that the reason why I like other people who have 1998 Mondeo's is because we can't currently afford something newer, etc - so it's the fear of having a garage charge a fortune to pontificate on what's wrong, yet having read other threads the symptons can be caused by a variety of issues.

Jools

[littlejohn5288]

sounds like your cat might be breaking down and blocking the pipe. Take it off and remove the inards if it is breaking down that will sort it temp till you can get another. That is if it is the cat

[Hearsepilot]

When your battery died your ECU was reset to default (Safe) values. Your CAT wont be harmed while its being re-educated.

If it will give you more confidence, disconnect the battery again for 10 mins. On reconnecting start the car and allow it to idle for 15 mins or so while it warms and finds its idle point. While its warm take her for a leasurly drive going through the whole range of the gears at legal speeds. after about 20 mins of that move to an A road and step up the rev range then onto an M road if you can and further up the range. When its safe grab a lower gear and hold it throgh the rev range before changing up.

First chance you get grab her hair from behind yanking her neck backwards and make the bitch scream for mercy!

[Jools Alison]

I forgot to mention, since changing the battery the car actually seems to drive far "lighter" - i.e. seems more responsive, faster, nimbler. However it also does what I listed above since changing battery!

Don't know if this helps with peoples thoughts on possible remedies?

Jools

[Jools Alison]

Hearsepilot, on 08 January 2011 - 12:22 AM, said:

When your battery died your ECU was reset to default (Safe) values. Your CAT wont be harmed while its being re-educated.

If it will give you more confidence, disconnect the battery again for 10 mins. On reconnecting start the car and allow it to idle for 15 mins or so while it warms and finds its idle point. While its warm take her for a leasurly drive going through the whole range of the gears at legal speeds. after about 20 mins of that move to an A road and step up the rev range then onto an M road if you can and further up the range. When its safe grab a lower gear and hold it throgh the rev range before changing up.

First chance you get grab her hair from behind yanking her neck backwards and make the bitch scream for mercy!

Hearsepilot - I like your style - started very professionally - and then a good dose of filth at the end - made me laugh! Thanks!

[littlejohn5288]

i was just finking that the ecu has had 10 days worth of driveing to learn its parameters which should be amble time if it has been driven for a decent period.  try the ecu reset again and if that still dosent work time to start exploring other options.

[Jools Alison]

littlejohn5288, on 08 January 2011 - 04:14 AM, said:

i was just finking that the ecu has had 10 days worth of driveing to learn its parameters which should be amble time if it has been driven for a decent period.  try the ecu reset again and if that still dosent work time to start exploring other options.

In reality though, it's had 5 mins to the shops and back following the change of battery and then 4 x 45 mile journey to work (2 there, 2 back home), and 5 mins to the shops yesterday. I can see that at high speed the ECU may need to relearn it's way through the rev range. But the loss at very low speed yesterday is the great concern,

Previously to the Mondeo (bough Jan 2010) I had a 96 Vectra which did something similar though in fairness that car was rubbish and you had to keep the revs going or it would stall (MAF sensor and Cam Sensor). Got made redundant in Feb 2009 and had to sell my sports car to keep afloat and bought a cheap Vectra. That blew up after nearly a year, and so got the Mondeo - which has been great.

Where I worry is that this hesitancy at high power, and yesterdays loss of any response for a few seconds at low speed have only occured since the battery change, and I wonder if the new battery is so good that it has found a weakness in the plugs, leads, coil pack that the old battery didn't - hence why when driving 99% of the time now the car seems so much more responsive. Then that leads to wondering if that with such a good response now, is the CAT internals so bad that the new performance found is 1% of the time struggling agianst a blockage in the system?

Will disconnect battery now and leave for  while, and reconnect and give it a blast and report back.

Have looked at a lot of other threads on here, and sadly the threads don't show how the matter was eventually resolved.

I'm used to Japanese sports cars, and am more comfortable with them when I can feel a problem as I've had so many I know what causes any issues with them, Whilst the Mondeo is cheap to buy, run and own, it hasn't felt perfect until changing the  battery - but I now have "pay back" with the "blow back".

Jools

[Jools Alison]

OK - have disconnected, washed car, checked vacuum hoses, recoonected battery.

Let it idle for 15 mins, and then took it out for 20 miles of hard running. Results:

Redlined it in 1st, 2nd, 3rd, as close to redline in 4th, and up to around a light jog in 5th. Hitting walking pace before running out of straight road or coming in to traffic.

All felt fine, save for a slight "flat spot" around walking pace, then foot to floor and it clears through.

Maybe I should have mentioned that a while back I had a mega hole in middle section of exhaust, have used a large Halfords metal sheet and jubilee clips to cover hole - am satisfied hole is not letting air in. Exhaust system middle section is pretty corroded underneath, though whether there are aditional holes elsewhere in system, without putting it on a ramp won't know.

Exhaust gases normal light cloudy throughout run. No hesitation or erratic idling. Checked timing belt all tight there.

I have a feeling that doing a full change of exhaust (and cats), change a few sensors, and doing a timing belt change, and replace coil pack, leads & plugs will result in this car being absolutely on the money - sadly the cost to do all that outweighs the value of the car. I have MOT coming up end of the month, and I'm sure I will need discs & pads all round (not too expensive I expect - £120 parts & fitting I think). May have high emissions at MOT which would then lead to suspicion is is CAT / broken exhaust causing the hesitation.

I know when I've had Jap sports cars that a dodgy O2 or Lamba can create similar hesitation at speed, and a dodgy dizzy cap, plaugs, leads with lower revs.

Will take again for a blast tomorrow and reprt back. Thanks for all the help so far.

Jools

[Jools Alison]

Ok - further update - just done a 10 mile round trip to Tesco - all fine there, when exiting car park on way back accelerator not responsive for about 4 or 5 secs, then revs came through, and all fine way home.

[thegfb]

I'd check that the battery connections were correctly re-tightened after the new battery was fitted as a first.

[Jools Alison]

thegfb, on 08 January 2011 - 05:19 PM, said:

I'd check that the battery connections were correctly re-tightened after the new battery was fitted as a first.

Thanks - but I'm happy with the connections - have double checked though.

[Jools Alison]

OK - another update on this - hoping someone reads it and makes a comment to help guide me please!

10/1/11: Drove to work, some minor hesistancy for approx 15 secs in 4th / 5th approx 55mph on a 45 mile journey, Coming home, seemed to feel a "air block" in the power at approx 50mph while climbing a hill some 7 miles in to journey home, acceleration felt "restricted (as if engine/exhaust could do with a good fart!) lasted for approx 2 miles between 3rd and 5th. Needed to get fuel - level very low - put half a tank in - no problem rest of way home (30+ miles) - in fact car was perfect.

11/1/11: No issues what so ever either to or from work - so 90 miles - perfect (other than need to get my brake pads done).

Could it be the fuel I put in the car straight after changing battery (same day) may have been a bit dodgy and clogged the system? Will update later in the week in case problem returns!

[Jools Alison]

18/01/11: Final Update - as this may help others:

Have filled up 2 x half tanks since the last update - no further hesitations of sense of blanki spot in acceleration or loss of accelerator in 1st - so am going to out his down to a dodgy half tank of fuel a few weeks backs, maybe having dragged some crud through the fuel lines.

If anything crops up, I'll post.

hopefully if anyone else suffers this, they won't need to panic!

[Jools Alison]

18/01/11:Still got a "smokey" exhaust - light cloudy fumes throughout journey, esp. when pulling away in 1st gear - but guess this is an old exhaust, but did note someone posting that change of spark plugs has solved this?????

[Bin_Man]

Hesitation as you describe on a MK2 is almost always ignition related and most of the time its the leads.  Take out the spark plugs and check the white insulator part for light grey or black lines on them - they may look like very fine cracks, or could be more clearly defined.  This is a sign that the voltage from the lead has been tracking down the outside of the plug and earthing on the head, rather than travelling through the plug and sparking.

If you find the marks, or if the plugs leads are of some age, change the plugs AND leads at the same time.  The Ford leads are surprisingly reasonable and often less than the Halfords equivalent.  If you can get hold of some, a little dap of silicone grease on the plug ends will help to keep water out and stop the tracking issue.

If the cat is breaking up badly, you often get a rattle and the car will almost certainly fail an emissions test at MOT time.  Personally I doubt its that.  If you have changed the plugs and leads, the next most likely thing is the MAF sensor.  that might well have been knocked as you changed the battery, so its worth checking the electrical connector for security and corrosion.  If there is nothing obviously wrong, try uplugging it and see if the car runs any better.  If it does, its highly likely the MAF has failed.  Easy to source a used replacement and they are pretty much "plug and play".

Oh and I've edited your earlier posts to make it *completely* clear that you weren't exceeding the speed limit on a public road when testing the fault.