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I've got a very late Mk2 Mondeo, 2000W reg, 1.8 petrol, with a gas conversion fitted too. Anyway...
For the last 2 days, all of a sudden, it just won't pull! And the problem is the same on both gas and petrol, so it's not down to either fuel system. The best way to describe how it feels like right now, is a Turbo Diesel car that has gone onto "limp home mode" and the turbo isn't boosting. This is what my old Passat did a couple of times, and it ran fine just with very little power.
But this is a 1.8 petrol engine, no turbo, totally standard aside from the LPG on it. I'm wondering if it's maybe a poor spark, so would new spark plugs be a good idea? Or possibly HT leads? But then it's been a looooooong time since I've had a petrol car, and I've forgotten more about them than I can remember Vs diesels.
Oh, and it's definitely still running on all 4 cylinders, everything sounds exactly as it should, it's just VERY low on power and won't pull through the revs... 70mph on the dual carriageway, downhill, was only just achievable over about 2 miles!
Hmmm, low power and no misfire doesn't sound like ignition. Ignition usually works or doesn't, sometimes intermittently.
I'd say your best bet is to get someone in your car who's with the RAC/AA any car cover. 😉
Although, having said that, I had both out to a car of mine once with no joy. Then an independent 'expert' with fully kitted van who advised burnt valves. I completely rebuild the cylinder head at considerable cost and time (two weeks off work) to have the exact same issue! Grrrrrrr. Towed it to the main dealer who spent a couple of minutes testing stuff and the cured the problem by replacing the intermittently faulty distributor rotor arm...cost £5. Even the 'experts' get it wrong sometimes.
I'd be wondering, from those symptoms, if your knock sensor was giving false output. But I'd pretty much bet it's something simpler and your symptom list isn't complete (no offence, just from general experience with people with car issues!). False trggering knock sensor will silently pull the ignition timing so you get sod all power. That said I'd expect it to throw an error at some point for that, but maybe not.
Quite unlikely that a fault with the fueling or igntion system would create a fault with such dramatic power loss without misfire. Are you sure you're just not listening closely enough? Misfires at 3000rpm are not always easily noticeable.
f-m - that thread just shows how little people can understand about cars, their sensors and how to diagnose/fix stuff.
Quite unlikely that a fault with the fueling or igntion system would create a fault with such dramatic power loss without misfire. Are you sure you're just not listening closely enough? Misfires at 3000rpm are not always easily noticeable.
OK, it's not misfiring at tickover for sure. I think it might be starting to higher up possibly. Don't know for sure though.
Extra symptoms... Errr... Well, this has come about after a couple of days of not being driven anywhere, and the rather "damp" weather we've had of late. I'm wondering if there's poor contacts somewhere between the dizzy and the Spark plugs that a bit of contact cleaner might help with... So might try that tomorrow.
Also, how often should you really change the spark plugs? And if spark plugs are on their way out, what would the symptoms be?
Fuel filter?
And daft as it sounds, is the throttle actually connected properly? I had similar symptoms for about a week on a motorbike, drove me nuts. Turned out the throttle cable had slipped off the cam/lever on the carb so was only opening it a tiny fraction.
Fuel filter?
Same problem on both LPG and Petrol. Kinda eliminates anything to do with the fuelling system. If it was one not the other, then I'd know it was fuelling problem.
And daft as it sounds, is the throttle actually connected properly? I had similar symptoms for about a week on a motorbike, drove me nuts. Turned out the throttle cable had slipped off the cam/lever on the carb so was only opening it a tiny fraction.
Definitely. If I press the throttle further when at say 2k rpm, it chokes it, as if it was running a big carb and you gave it full throttle at low RPM on an engine with a lumpy cam. It's definitely getting the fuel it needs, but it's not running right. Hence why I'm thinking its got to be ignition related.
Possible damp has caused you some issues, worth leaving it running in the drive for a bit to heat up the bay and drive out the damp if possible.
Anything that drops it into limp mode should really flag a code.
Plugs - depends on the type and the engine. If they're at fault you'll generally find it happens at the hardest to ignite points of operation - just as you get on the throttle and at full throttle. Normal copper plugs last 12-24K miles, modern iridiums are a bit better but not much but you'd notice a failing plug.
For you to lose power that drastically you'd have to have spectacular misfire problems which should be obvious or you're in limp mode, or you have a sensor on the edge of normal operation tricking the ECU into being lame.
Definitely. If I press the throttle further when at say 2k rpm, it chokes it, as if it was running a big carb and you gave it full throttle at low RPM on an engine with a lumpy cam. It's definitely getting the fuel it needs, but it's not running right. Hence why I'm thinking its got to be ignition related.
If it's fairly abrupt it's possible its a misfire and you just are not hearing it. Is it RPM related or throttle position related?
blocked /dirty air filter?
falkirk-mark - Member
http://www.talkford.com/topic/116769-maf-sensor-where-is-it/
This I reckon, I had the same symptons on my Mk1 (I think from what you've written above - what feels like a massive dead spot?) and it got to the point where it cut out. Cotton bud + isopropyl alcohol to clean the sensor sorted it.
Possible damp has caused you some issues, worth leaving it running in the drive for a bit to heat up the bay and drive out the damp if possible.
Was no better after a 25 minute blast last night, back from my Dad's house... Well I say blast... Struggled to even achieve the speed limits for most of the journey!
Plugs - depends on the type and the engine. If they're at fault you'll generally find it happens at the hardest to ignite points of operation - just as you get on the throttle and at full throttle. Normal copper plugs last 12-24K miles, modern iridiums are a bit better but not much but you'd notice a failing plug.
Thinking a new set of plugs won't go amiss actually... Just read up on cars on LPG and spark plug issues. Seems wise to change them often, possibly as often as the oil. Certainly doubt the plugs have been changed in a while. Will go get some tomorrow.
For you to lose power that drastically you'd have to have spectacular misfire problems which should be obvious or you're in limp mode, or you have a sensor on the edge of normal operation tricking the ECU into being lame.
I'm thinking it is in limp mode, but there's no obvious way to tell unlike with my old VAG TDi's.
If it's fairly abrupt it's possible its a misfire and you just are not hearing it. Is it RPM related or throttle position related?
Hard to tell, I can't achieve any RPM of note. Takes an age to reach 3krpm even, so tending to short shift at the mo.
blocked /dirty air filter?
Nope, brand new one 4k miles ago, when I serviced the car. Also, a dirty filter doesn't make this much difference, trust me!
This I reckon, I had the same symptons on my Mk1 (I think from what you've written above - what feels like a massive dead spot?) and it got to the point where it cut out. Cotton bud + isopropyl alcohol to clean the sensor sorted it.
Does make sense come to think of it. I'll get the Haynes out in the morning, MAF sensor should come out easily am I right in thinking? Very easy to get to on my old VAG cars anyway... Will get it off and give it a clean if I can.
petrol don't have an MAF as such it was replaced with TMAP witch is on the inlet manifold about size of match box held in with one screw (star type) with wire connector about half wasy down,its pain to get to mind you
From link
I've had this twice on petrol Mondeos and both times it was the Catalytic converter that had failed. On both cars the honeycomb had broken up and was restricting the exhaust flow. On the 1st I replaced it but on the 2nd I took it off, smashed the insides with a long screwdriver, emptied the crap out then refitted the empty pipe. Both worked but the one with the Cat replaced drove better and could pass the emissions test.
http://www.picoauto.com/applications/lambda-sensor.html
Look at the bit about O2 lambda sensor and loss of power on here
http://www.gomog.com/allmorgan/ZetecIdleIssue.htm
It could be a thousand and one things - best bet to start with is to get the fault codes read (not all will flag up a warning light on the dash).
I've had this twice on petrol Mondeos and both times it was the Catalytic converter that had failed. On both cars the honeycomb had broken up and was restricting the exhaust flow. On the 1st I replaced it but on the 2nd I took it off, smashed the insides with a long screwdriver, emptied the crap out then refitted the empty pipe. Both worked but the one with the Cat replaced drove better and could pass the emissions test.
Arse! Cos guess what... My Cat has been rattling a bit! Hoping it's not this.
Gonna try and eliminate as many factors as I can today, but have a feeling this is going to cost to fix properly! 🙁
Might be worth a look my old Metro Turbo had the same symptoms when a baffle collapsed in the silencer box
We had the same problem with a Toyota. Took ages to sort then found out the inside of the exhaust had collapsed inside.
Could be the air/fuel regulator as well but you would have to plug into a computer to find out probably
Anybody know/own anything for reading fault codes on old Fords?
I've been VAG TDi almost exclusively for years, then Beemers before that. Never owned a Ford before this, and bought it cos it was cheap and in good nick and had an LPG tank (and the car cost less than the cost of an LPG conversion would have done!).
Is there an OBD style port anywhere that you can plug a fault code reader into?
There might be one under the steering wheel
http://www.talkford.com/topic/158824-obd-location-on-mk2/
on here
http://www.ebay.co.uk/itm/Car-fault-reader-code-scanner-diagnostic-tool-OBD-2-CAN-/230644533100?pt=UK_Diagnostic_Tools_Equipment&hash=item35b37c476c
and cheapo code reader
If you were nearer I'd read the codes for you, sorry!
Rear springs gone eh?
Too much "back seat fun"?
eh?
Cheers coffeeking, I can get the codes read, but it'll probably cost twice as much as one of those boxes to actually do it! Think I might have to invest...
Just been to the post office and back in it. Almost certain it's an issue with the Cat, so thanks above for pointing that out. The car is 12 years old, and has only done 44k miles from new, and has never had a new exhaust. Thinking the cat (which was rattling quite a bit last week, and is now eerily silent) is blocking the exhaust. Put it this way, it drives like a scooter with a washer still in the exhaust. Pulls fine up to about 2250rpm, then power tails off very rapidly. It's definitely not misfiring, I've had a good listen. Just feels very asthmatic.
Right, next question before I go and get ripped off... How much is a new Cat for a Mk2 Mondeo likely to cost? And how long should it take to fit?
Buy exaust,,,,,
You mad ,
Take it to your friendy exaust center and get them to cut the top open remove cat bits reweld it refit and still mot legal
20quid should cover it
Stuarty
I meant price on the parts to be fair. It would fail it's MOT in 4 months without a cat, as would anything built since 1992, though for the meantime it would run reasonably ok.
How much is a cat these days? Labour's not so much an issue, got a guy that providing he's free enough charges me £15 an hour generally so all good.
Does it run fully electronic ignition, or is it dizzy, or a hybrid?
Mine (an 80s engined 90s vw) has been suffering from increased power, running rough, idling and intermittent cutting out at low rev's but never actually misfiring.
Then one day after it was running particulary powerfully, wouldn't restart. the coil had finally let go, but also the crazy electronic/mechanical hybrid dizzy + rotor was heavily worn which gave the effect of running about 20degree's advanced + its own advance.
Another thing thats worth checking is vacuum hoses, never underestimate how these affect an engine. Used to run a late 90s fiat coupe 20v turbo and that thing was completely anal about its vacuum/breather system, had to replace every last hose + junction (some are inaccessible without engine out), and then it ran fine, for about 18months when yet another hose expired (everything else on it was solid though).