Sonny Jim went off in his old Fiesta this morning a came back a bit later saying he'd got some car troubles.
It seems it started off revving highly itself and ticking over very high (2k+).
He managed to get it home and we have just had the air filter off to check stuff out.
The contacts in the plug to the Throttle-plate control motor were a bit corroded and after giving them a few plug actions and some electrolube it seemed it then started behaving ok?
So now, from warm, you start the car and initially the revs go to about 2k then over the next few seconds drop down to a reasonable tickover.
However, he took it out for a quick test drive and feels that when say stopping at some lights or a junction the revs are taking a bit of time to drop as low as expected (he may be imagining it). ;-)
So, before we start looking at all stuff in that area, is this a known issue and if so any advice where to start please (I'm thinking ahead in case this is an early sign of something failing completely).
And then check a) the air temp sensor in the air filter, these engines can have a propensity to spit back and melt the ATS, b) the idle switch on the end of the stepper motor rod for being electrically open cicuit at all times.
Clutch (if fitted) and brake pedal switch. Wrong tail light bulbs back feeding into the brake light circuit will cause funny issues on these too.
And then check a) the air temp sensor in the air filter, these engines can have a propensity to spit back and melt the ATS, b) the idle switch on the end of the stepper motor rod for being electrically open cicuit at all times.
Clutch (if fitted) and brake pedal switch. Wrong tail light bulbs back feeding into the brake light circuit will cause funny issues on these too.
And then check a) the air temp sensor in the air filter, these engines can have a propensity to spit back and melt the ATS, b) the idle switch on the end of the stepper motor rod for being electrically open cicuit at all times.
Clutch (if fitted) and brake pedal switch. Wrong tail light bulbs back feeding into the brake light circuit will cause funny issues on these too.
I went out with him after my first post and watched when he gave it a rev (say to 4K). When he let off, it dropped quickly back to 1500 rpm and then slowly back to about 1000 over the next 5 seconds.
It 'looked' ok at first glance and is it something that can be measured with a DMM (Looking for resistance, any idea what values etc please)?
Ok, I also spotted that (and it's wiring / plug) so I can easily put a meter on that.
Wrong in what way please Tim? Fitting, wattage etc? We changed most of the lamps when he was given the car a few months ago and all has been fine till today but tail lights should be an easy thing to check (intermittent faults excluding).
I have heard of people with the same sort of fault curing it by disconnecting the battery for half an hour or so, the ecu then re-learns the sensor values and all is fine. you have little to lose by trying it, unless you don't know the radio code :)
Ah, ok, I have read that elsewhere for other vehicles as well.
Well, I'm pretty sure he'd sacrifice the use of the radio for a properly working car so as you say, nothing to lose. ;-)
It's funny, after all the issues we are still having with the Meriva I was hoping this 'older' car would end up being straightforward. I was hoping for a set of points and a carb but no such luck ... back to chanting magic incantations to the mystic semiconductor. ;-)
Cheers, T i m
p.s. They were (are?) going up to Scotland (from Norf Lundun) in the
50,000 mile Fiesta on Sunday, rather than using her 185,000 mile 1.2 Corsa.
Check the TPS at idle, needs to be under 0.8v for a good fall back to idle..
Tail/ Brake light bulbs offset pin v equal pins. If they are jammed in wrongly the tail lights can back feed the brake circuit and upset the idle control where the ECU uses it. VW's very common, but i've seen it on Fords also.
Ah, yes, I think we came across that on the way home from collecting it. Offset bulbs, contacts all cleaned and inserted properly. ;-)
Ah.
Ok, well I got him to run me up the shops in it earlier and it didn't do the over-revving thing again so that bit seems to be sorted at least (I believe some corrosion in the motor plate connector). It's quite possible that the slow settling of the tickover may have been there all along and only highlighted with this recent problem?
However, on the way back I further noticed a 'clonk' (during medium engine loading / unloading) and when we got home I gave the engine a push-pull and found the lower bolt on the o/s engine mount was half hanging out. The top bolt was also slightly lose and hence allowing movement in the mount. The end of the thread was a bit mullered so I ground it off with the bench grinder, ran a 10x1.5mm die down the remaining threads and a matching tap into the mount hole (you could just do it with the road wheel on full right lock). Just nipped the lower bolt up, fully tightened the top bolt and then finished the lower bolt. A quick road test and one less 'clonk'. I'll probably put a new bolt in there when I can get one.
I dropped them off at his works mean tonight and found the clutch very heavy? Also the temperature gauge wasn't really getting onto the gauge and whilst the heater was warm I'm not sure it was 'hot'. I'll check the actual temperature when I can but suspect a stuck (open) thermostat?
He's only young and whilst keen, never really had any parental mentoring / guidance / support with all this (he's our live-in SIL to be). I always had an ear for the odd / new noise and would always question anything and everything I heard. I also stripped and rebuilt my first engine (a seized Fiat 850 I bought for 15 quid) when I was
14-15 so all this is just part of what I assume everyone would have the same interest / feeling about. I'm regularly reminded that isn't the case (especially these days).
I like resolving all the nuts and bolts stuff, it's just all this electronics stuff that gets on my wick (mainly because of the complexity of testing and exchanging stuff).
After a 100 mile round trip in the Meriva yesterday, watching the speedo (and revs / temp) bouncing around worse than the one in my old Morris Minor Van all those years ago, I got home and whilst daughter watched the rev counter I pulled the plugs / loom about onto the ECU. It did seem that there was some correlation between what I was doing and what she was seeing on the rev counter but to eliminate the ECU (leaving a bad wire / plug etc) I would have to find (borrow) a suitable sound ECU and program it in (if I can with an OpCom unit? If not then it's going to cost a few quid (to someone with a Tech 2) just to find out if it is the problem or not) ;-(
Regarding the temperature gauge, the temperature sender on my 1998 Fiesta (with a 1.3 petrol engine) failed, causing the temperature gauge to read cold (can't remember whether the needle moved a bit or not at all).
Mine also did the over-revving thing intermittently. Unplugging and re-plugging all the accessible multi-pole connectors *seemed* to help, but that might just have been my imagination.
Yeah, I've changed a few senders in my time and I think you can get different variations that could impact the temperature readout. I'm not sure I'd play with that sort of thing on anything with an ECU though. I think the first thing would be to just change the server and maybe put the IR thermometer over it and check what is going on.
Or it could have been like with us and definitely signs of corrosion around some of the pins. Un / re plugging would 'wipe' the connections to some degree.
Yeah, this one seems to be as well and especially nice that it was given to him. ;-)
And at ~50mpg he's not doing too bad with any company mileage either. ;-)
if the engine is not coming up to temperature (either in reality or just misreporting to the ecu) then it is pointless to look further till that problem is solved. A fiesta should be putting out serious heater warmth within a mile pf a cold start.
I have never seen a petrol fiesta that will get significantly better mpg than 38, so either your one is incredible or there is a fault in the calculations.
I had a 1998 1.3 petrol Fiesta, and I consistently got 50mpg (I was a bit obsessive about measuring fuel consumption). I think that was partly because it was a bottom-of-the-range model without power steering or air conditioning, and as a result Ford had decided to fit a slightly taller final drive ratio, compared to models with more power-sapping anciliiaries. I also did most of my driving on motorways.
Well, quite, but I only noticed this temperature thing after all the other stuff. However, the temperature readout doesn't seem to have changed since he got the car (apparently) but the over revving thing has (been and now gone it seems).
Hmm, when I drove it for the first time properly yesterday (and from cold) I'd say it took more like 2-3 miles before I noticed any heat heat as such.
He has been keeping a paper log since he got it and the transferred it to the Fuelly app and carried on with that since.
2752 miles 323.3 litres so that's your 38.7 average (don't know where the 50 mpg came from then).
That said, when on long runs it does seem to get quite a bit more. I'll get him to check it up to Scotland and back.
We changed the oil and filter today and I'd have to say the revving thing seems to have gone away (in any case ... so hopefully *was* just corrosion on the connectors). When they get back I'll probably get him to replace the temperature sender and stat as well. Not something I wanted to risk just before a long trip (except I would have done it if it were my car as I would have questioned it sooner (in fact I did (here) when we first got the Meriva and did the cam belt, tensioner and water pump at the same time as the stat).
Cheers, T i m
p.s. Talking of the Meriva ... yesterday morning that fired up on the button, ran for possibly 1 second and then died. It took a couple of attempts but then started and ran fine. I drove it for about 15 miles (mostly with no temp, revs or speedo) then left if for a couple of hours. Then it wouldn't start so left it for another 4 and initially it did the same thing (ran for a second, died and wouldn't restart). I removed the neg battery lead for a few seconds gave the dash a bash (partly out of frustration, partly to see if it was a connector issue) and then it seemed to start (and run) fine.
Then the other day after a 100 mile round trip (again, mostly with the
3 missing dials and a constant ignition light), it 'seemed' that moving the loom / plug on the ECU made the instruments to cut in again? Two (or more) faults?
I think our SIL (to be) has seen plenty of similar results also when on the longer runs (initially bringing it back from Bristol to London when he got it).
It's (hopefully) going to be doing 1000 miles over the next few days as they visit his folks in Scotland so that will be a good time to check for the long run stats. ;-)
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