Hi there,
1996 Ford Fiesta Encore with an engine revving problem.
When clutch depressed, engine revs away even with foot off accelerator until speed drops below 5 or so mph. Also works the other way (e.g in neutral, no accelerator, start rolling down a hill and engine revs run away). Car also acts as if it has cruise control, e.g. drive at 30mph, foot off accelerator and car continues at that speed.
I have heard said that the idle speed control valve could be a problem. Could this be the case and if so, is it an easy job?
Thanks in advance,
Terry (aka Old Suttonian)
Edited by Pugugly on 02/03/2009 at 17:23
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idle control arrowed
tinyurl.com/2x7e7w
ignition off
undo the two bolts 10mm and disconect the wiring connector,clean out the insides of valve with brake cleaner and replace,this cures the problem 50% of the time,do not stick a screwdriver in here as the valve is brittle :-(
the other thing is on this car there is an electrical connector connected to the clutch pedal (the bit your boot goes on) ,make sure it is connected properly so that when clutch is in normal position the switch is closed a multimeter will confirm
both these above articles need to work perfectly to cure your dangerous problem
a new idle valve is £50 +vat at my factor
scrappies sell lots s/h but can you be sure its a good one,i wouldnt bother unless local and they ley you borrow it to try/highly unlikely?
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Cheers, Bellboy.
I'll give this a go and report back.
Alll the best,
OS.
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Bell-boy that is a very disturbing picture in your phot-bucket file, is it somewhere by where you live ?
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Bell-boy that is a very disturbing picture in your phot-bucket file is it somewhere by where you live ?
>>>>>>>>>> which one i just cleared them all off?
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Armageddon - is West or South Yorks ?
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Armageddon - is West or South Yorks ?>>>>>
>>>>>>>>>it was in response to a post a few months back ,cant remember what though
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Terry
Your throttle position sensor is not getting the message to the ECU that the throttle is closed. [Ford have many TSBs out on "idle flare."]
The moment that the ECU gets a vehicle speed signal, it opens the idle valve to the "drive" position and gives the symptom that you have.
If you were to plug in a scanner and check the throttle status, you'd find that it was showing "part" not "idle" with the throttle closed.
You need to rework the wiring between the TPS and the ECU to let the message get through. The in-line multi-plug is the place to start checking for corrosion. There is a wire shortening mod, but it's not often successful.
If all else fails [and the dealers often do] drill out the brass bushes on the TPS's mounting screws and twist it backwards to fake the idle reading. Criminal bodgery; but it works.
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screwloose ive never had to do that on a mk4 its always been what i posted
i usually check speed sensers by having car in neutral and running and pushing the car forward,the revs should rise.
never had to do a tps on these but done loads on the old mk3"s
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bb
Lucky you. I've done dozens - and Pumas and Ka's. The dealers now send them to me. All their TSBs and upgrade dumps to alter the ratch voltage parameters don't seem to help....
A lot of them don't have clutch switches and, as you say, the revs do rise in motion - but, at closed throttle, they should drop instantly to idle once the hall sensor stops switching.
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thanks for the update Screwloose
knowledge stored :-)
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Cheers for that, Screwloose.
You mentioned corrosion. I spoke to a guy today and he mentioned that the ECU of the Fiesta Encore was prone to corrosion - some bad design allowing water (from wherever) to get at the unit/cabling/conector.
I'll have a look at the cabling/connector and also the suggestions by Pugugly.
Thanks guys,
Old Sutt.
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Guys,
Had some success today. Had alook during lunchbreak and pulled connector off Throttle position sensor and cleaned the blades in the connector. The socket had gold wipers (I hear that the mod from Ford is to fit a gold-wipered connector to replace the problematic tinned connectors). Did same to Idle control valve (just in case). The only thing I now get is a bit of overrev between gear changes. No engine runaway and no "cruise control" now.
Going to clean the Idle valve tomorrow.
Cheers guys,
Old Sutt.
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Terry
While your on a roll; find the black lump of an engine multiplug connector [about 15 pins - inside a plastic cover] on the bulkhead and give that a good clean too.
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Cheers Screwloose,
Just looked at both connectors. Someone had been in there before me! Gave things a wipe (looked like there was a smear of Vaseline on most pins). No further change as a result. Things are 100 times better then they were, though. Not sure whether to leave it as it is or pursue further. Not knowing much about these modern cars with ECUs, does the ECU "learn" as it goes along, and would pulling the power to it to reset it have any mileage?
Thanks again for all your help.
Terry.
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Terry
Very commendably; Ford do grease those terminals. [French makers please note!]
The idle "ratch" voltage is a floating value that constantly re-sets itself; so I'd not risk de-powering the ECU.
The ratch will set itself to the lowest voltage that it's seen in that drive cycle and assume that the throttle is closed if the TPS signal voltage matches it.
That's where the problem lies with these Ford EEC systems. Any slightly poor connexion that gets even a tiny bit worse as it warms, won't let the signal drop down to the current ratch value.
The ECU then thinks that the engine is still at part throttle and keeps the idle valve wide open in the drive position.
Adding a simple "closed throttle " on/off switch to the TPS would have saved so much grief.... A classic case of being a bit too clever.
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The cruise contol thing is what mine has when you release the throttle the car dosn't really slow down. Ironic as my olf MK3 had a similar TPS fault.
I just feel like I am getting the run around all the time, TPS, idle control valve, wiring loom.
Screwloose you really seem to know this engine more than anybody else I know, so I am goingto look at the TPS before do anything else.
On my MK3 I just cut the wiring and made my own loom but it was a tempory measure as I knew the car would be scrapped (ironicly its back on the road now after new owners but a new HCS in) and it probably runs a lot better than my new one!
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Rattle
First do bb's rolling test; just stop on a slope, wait for it to idle and let the brakes off. The revs should rise, or the vehicle speed sensor[VSS] isn't getting the message to the ECU.
Once the VSS is proved; check the wiring plugs and the TPS plug, which should be gold - don't put silicone on them.
Last resort; drill out those TPS brass bushes.
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Thanks, is this test done in gear?
Am I suppose to let the car roll back and do Itouch the throttle?
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No; just stop on a downslope; footbrake on; into neutral - then just let it roll forwards at walking pace and the revs should rise, then drop back to idle the moment it stops.
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Thanks what happens if the revs do/or not rise does it indicate anything? Is this directly related to the TPS?
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If they do not rise, then that indicates that the idle valve hasn't been pulled open to the "drive" position.
Possible causes; the VSS signal not received by the ECU; the idle valve - or many other things.
This isn't a TPS-related test.
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Hi HJ
Having revving problems myself, and spotted this!, just to say if you need to disconnect the speed sensor to cure the problem, then the speed sensor is working perfectly, and telling the engine management that the car is moving. this means the problem lies elsewhere.
I bet you get the same effect if you remove the TPS plug which removes the throttle position input. the car will probably run perfectly without one or other , but do the "cruise control" thing with both inputs
Has anyone found a real and permanent cure for this problem ?
Cheers Wee Jim
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Wee Jim
I get loads of these sent my way from various dealers. The cure [after making sure everything else is in order] is to make sure that the ECU is in no doubt that the throttle is in the idle position.
These have a unique constantly-learning system for what TPS voltage level means idle. Ford call it a "ratch" voltage. If it's reading a shut throttle as part-throttle, then it keeps the idle control valve in the driving position - fully open - all the time it sees a speed input.
As you so correctly say; [I wish more people saw things as clearly] disconnecting the VSS is not finding the problem.
What engine code and year is yours?
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Hi Screwloose
Its the HCS 1.3 EFI 60PS ENGINE , vehicle built on 15 05 97 and using EEC 1
Cheers, Wee Jim
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My son's 1996 Fiesta Classic 1.1 is behaving exactly as the 1.3 Endura described . The problem gets much worse when the engine is warm.
I have removed the air filter and found a solenoid to the right of the air intake which carries a piston in the centre of it, pushing against the accelerator mechanism. If I push back on the mechanism, the revs drop back to idle but as soon as I release the pressure, the piston moves back and the revs increase to a high level again. I am not sure what this solenoid is called but I suspect, following the discussion that this might be the idle control valve.
My local garage is not very keen to get involved in its' repair - is it too specialised? I shall begin myself though and clean all of the appropriate spade ends and see if this makes a difference.
I would be very happy to have any additional advice or guidance that is on offer.
Jeff
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Jeff
Ignore everything above; you've got a Bosch single-point throttle body that is a completely different animal to the Ford multi-point systems above. There are dozens of variants of these fuelling systems on this engine alone.
That motorized throttle stop is told what to do by the ECU. When you first turn-on the key, does it power in and out to set the throttle for starting? If you let the car roll forward in neutral with the engine "idling," do the revs rise?
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Screwloose,
Many thanks for the prompt reply. No wonder my garage is fighting shy of the problem!
This is going to be a difficult one for me as the car belongs to my son who does not live at home anymore, so I only see the car infrequently.
He is going to bring it round this afternoon though, so I will see what is happening then. I will certainly check out the two points that you mention. The second one might be a bit of a problem as it's a bit flat around here. I'll have to get him to push it.
I'll be back on the message board when I have checked the car. Many thanks, again.
Jeff
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hi screw loose im having exactly the same problem as evey1 eles , seems u know what ur chatting about , where can i find the speed sensor ? also if it dosent rev while starting from stand still and rolling down a road what will it be then ?
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finchy
I hate tack-on faults as it all get too confusing; what car, year and type of injection has yours got?
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it a mk4 fiesta 1.3 encore multipoint injection its a r reg so its a 96/97 only done 48,000 miles, bacically it all started i was driving home from work it started doin it i parked up for 5 minutes got bk in it and it was fine for about a week , now its just constant , only dose it while moving when foot down on clutch and put in to nutral whilst moving, iv read all these diferent posibiltys , and i want to try and narrow it down so i dont have to waist money replacing everything iv read
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OK; that clarifies things a bit. It's supposed to rev quite high when moving in neutral, but drop to idle once stationary.
Has yours got a clutch position sensor and does it have power steering?
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there is a plug at the top of my clutch pedal so im guessing it dose have clutch sensor , but it dosent have power steering , if im driving along and i put my foot down on the clutch the revs just go mad untill i slow down , same as if im goin along and take it outa gear completly
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If you coast in neutral; it should rev at about 3,000 revs, as the idle valve stays wide open in normal driving. Depressing the clutch should stop it revving.
This could be a clutch sensor fault, but it seems a bit severe, so the most likely cause is the "closed throttle" signal isn't being received.
Check the in-line engine loom connector for water and corrosion. The ECU plug suffers too; but that one is a pig to access.
Edited by Screwloose on 16/11/2008 at 20:18
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iv cleaned all the plugs i posibally can except ecu , where abouts is the ecu ? also how do i find the speed sensor? also its not only when the clutch is depressed it dose it if i slip it out of gear without depressing the clutch , but as soon as iv slowed down it will stop
Edited by finchy on 16/11/2008 at 21:44
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If it slows as you stop; then the speed sensor [on the top of the gearbox] is obviously working fine.
The ECU is in the passenger's kick-panel. Under a security plate, unfortunately.
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ahh rite dose sound like a pain to get to, ill give it ago , sounds like might be the plug on the ecu because iv bin having alot on damp in there recently and that maybe the cause .thank you , u have been a great help ,
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just wanna say thank you for your help, i managed to get the ecu and took the plug out it was full of gunky crap so cleaned it all out and its now running smooth , so thanks
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Hello,
I have a Ford Fiesta 1996 1.25 Ghia. It is doing exactly the same thing -- the revs are high between the gears or even when in neutral whilst the car is moving. I know that the idle valve was cleaned by a mechanic. I also replaced the MAF which cured some other problems (loosing power on high rpm, although this sometimes re-appears, but very rarely). So what should be the first thing to look for now?
An observation by me (which hasn't been mentioned in this forum or anywhere else) is that when I depress the the clutch in idle, the revs go up for about 500 and will stay so until the clutch is released. Basically, depressing the clutch on my Fiesta is the same as putting the foot on the throttle.
Edited by streever on 04/12/2008 at 23:46
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I think I'm on the verge of solving a similar problem (I just need a dry day and the car).
Ours is a 2000 1250 Zetec LX.
(apologies to the endura guys)
Our car has an annoying habit of letting the revs 'hang' when pulling up to a stop with the clutch in. They usually go up to about 1500rpm - 2000rpm and then a few seconds later settle back down to a normal 900rpm (?) idle.
You can pump the throttle at a standstill and it revs perfectly normally and always settles back down to the normal 900rpm idle.
I have cleaned the throttle position sensor, the idle control valve, the air mass sensor, I've unplugged the battery to reset the computer.
Nothing made a blind bit of difference......and the fact that it revved normally at all other times had me very sceptical that it would tunr out to be any of those parts.
I did turn up one interesting line of enquirey though and I thought I'd share it in case it helps someone esle.
It seems a likely culprit is the 'Power Steering Pressure Switch' (on the drivers side right near the front on the power steering lines).
There are 2 wires in a very exposed place and a little switch unit.
If the switch or the wires have corroded then this, apparantly, can be the cause of all sorts of weird revving problems.
It's all to do with the sensor/switch telling the engine/CPU when you are at full steering lock and the load is high on the engine, it's supposed to up the revs by about 100 or so rpms.
The switch is normally closed.
If the switch or wiring is donald ducked the CPU sees the circuit permanently open and so you get all sorts of odd things happening.
If it's all working properly the engine speed should drop if the connector terminals are shorted together and then increase when the short is removed.
If the engine speed doesn't change when shorting the connection then there's definitely a fault.
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Just to round off the story.
I had a look at the wires going into the switch connector (and one wire promptly fell off the connector).
I tried shorting the 2 wires going to the Power Steering Pressure switch and the engine did not respond at all, so obviously the wiring was duff.
I cut the wires and traced them back behind the headlight (Fiesta mk4s are so easy to take the lights out of) and cut away some insulation. Now when I shorted the wires together the revs dropped a little.
So, I have effectively by-passed the PSP switch and now all my rev problems have vanished.
Edited by gixxerman on 22/02/2009 at 19:18
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hello. I have a 1996 ford fiesta lx 'n' reg car.
i am having some trouble unravling the answer to the over revving problem.
i have this problem as I have noticed that some of you have mentioned, of "cruise control" and high revving when out of gear. when coasting the revs will drop to 1,500 then go back up again sometimes up to 3,500 revs. when slowing it seems to get more violent and higher revs. When coming to a stop the revs will still be up in the high figures and then after 20 seconds will drop to 700 revs until almost stalling. sometimes (intermittent) the car when in neutral after applying the breaks the revs will become so low the car shuts off. very embarrassing.
I have taken it to quite a few mechanics and even an auto electrician. none seem to know what to do with it.
any help will be most welcome.
thank you!
lew
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Hi
I have the reverse problem of this I think
The car keeps stalling (not cutting out)
I have a 97 1.4 Fiesta
It's happening when I'm in first and let the clutch off (not every time) and is very frustrating.
This is not down to my left leg or driving ability.
Does screwloose still post on here?
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Phil-
sorry, but no, he doesn't.
Shame, eh?
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for the endura-e crew on here i had the same problem on my 1.3 escort and after reading this forum i cleaned the icv as instructed above and disconected my battery for an hour and its been running smooth ever since. i had cleaned the icv previously with no change so i'd say its the resetting of the ecu that did the trick. but i now know why they called it the endura engine.......because you have to endura lot of crap from it. happy motoring :o)
Edited by mk6escortkid on 09/03/2011 at 11:48
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