Hello guys and girls,
This is my first time posting on this forum, so apologies if I've got anything wrong.
I'm having a nightmare of a time with this Fiesta and I've lost faith in my mechanic (family friend so I can?t be too harsh on him).
Symptoms the car is showing:
1) The car idles at a higher rpm. About 960rpm according to the pcm reader. And this doesn?t problem doesn't disappear once the engine has heated up.
2) There is a small stutter when pulling away in first or second gear.
3) The throttle is sticking in-between gear changes i.e. coming out of gear at 3000rpm, the revs will stay there even if the car is put into neutral. The only way I've been able to get it down is using the clutch in a higher gear or waiting until it drops - but you look like an idiot if you wait for the latter.
4) This one is intermittent. Whilst travelling at any speed, the engine will stutter intermittent. The stutter causes the car to lose acceleration and power, such like if the turbo was broken on a diesel. Increasing the throttle only causes the stutter to get worse; eventually the power does come back. Or I have to put the car into neutral and use full throttle until full revs come back. It?s almost as if the engine was seizing or fuel mixture running way too rich; the latter of which explains why increasing the throttle worsens the problem!
5) On disconnecting the throttle position sensor, the idle drops 100 rpm to about 860 rpm, but symptom 2) becomes a lot more noticeable and if you come off the accelerator fast enough, the engine cuts out.
Solutions that have been tried:
1) Sprayed the intake with carb cleaner with little change
2) Fitted a new Idle Control Value with no change
3) Fitted a new Throttle Position Sensor with no change
Any ideas on what it could be?? Thanks in advance :)
Regards,
Dil
Edited by Dynamic Dave on 13/09/2008 at 13:04
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Dil
Glad you've got access to a scanner; makes it a lot easier.
In live-data, at idle; what is the throttle status? Part, full or idle?
What TPS voltage is shown?
What is the power steering pressure sensor status?
Check; the PSP switch wiring; the engine loom connector.
If you've the means; also check the fuel pressure.
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Using a program called ScanTool.net 1.13..
There's nothing that says what the throttle status is. Rather the Absolute Throttle Position is 16.9% and Fuel System 1 Status is closed loop.
The car doesn't have power steering so that sensor is not going to be possible either.
Using a program called Digimoto..
I can also tell you that the car doesn't even have a sensor for the fuel pressure.
It's got a live-data recorded and I've manipulated that into a graph:
img143.imageshack.us/my.php?image=77146309yt8.png
Don't really know if it'll help much, but there it is!
There were some codes the first time we connected the reader but, to get a better idea, we cleared the codes and I'm waiting on anything to come up. Will be driving 50 odd miles tomorrow so that'll probably cause it come up.
This car was the most basic model at the time. No ABS, no PAS, they just about gave it airbags lol.
Cheers, Dil
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Dil
Ah well; better than nothing. At 17% it's pretty certain that the throtle status would have been in "part" and the idle control muzzled.
Time for legwork; measure the exact voltage on the centre pin of the TPS; all connected, with just the key on.
[As a temporary test; disconnect the vehicle speed sensor [3-pin plug above the clutch] and see if that improves it.]
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Need to go buy a 9v battery for my multimeter (doh!), so I'll get the voltage for you tomorrow.
I disconnected the VSS and the revs sticking inbetween gears has gone (thank goodness !); but that stutter while goin into gear has gotten worse. As for the idle rev, after running the engine a few minutes (with the VSS off and the coolant at 58 degrees), it stayed at around 1000rpm.
Also, those error codes I mentioned earlier. Well the original ones never came back; however, there's a new set:
P0401 Exhaust Gas Recirculation Flow Insufficint Detected and
C3100 No Description
Surely clearing the error codes should only have made the original ones come back, rather than new ones appear??
Edited by Webmaster on 25/08/2008 at 02:04
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It's got an EGR system?? What's the engine code in the chassis plate?
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Screwloose,
Sorry mate, had to get rid of the last laptop so haven't had access to the site!
Right, i presume the engine code is JAS (sounds like an engine code??)
I checked the voltage across the TPS:
+ve to chassis was +5.05v
signal to -ve was +0.86v at idle and went all the way to +4.68v on full throttle.
Also had a look in the main in-line loop for the TPS and voltages seemed to be consistant, so i'm ruling out corrosion there.
Cheers, Dil.
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Just saw that the theard heading states the car is a '99 year - that's wrong! It's actually a '97 R plate {Amended - DD}. Hope that doesn't make much difference :/
Cheers, Dil.
Edited by Dynamic Dave on 13/09/2008 at 13:05
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hi guys, new member here..
please could you let me know if this issue was resolved?, as im having the exact same trouble.
i have no access to a scanner or any diag tools, and as i'm on the skint side, need to keep costs down to a minimum.
my problems are pretty much as described by the OP.....wildly varying idle revs, loss of power when setting off (unless i boot it...and end up wheel spinning away), and also "jumpiness" or juddering when im cruising in 3rd, 4th and 5th...unless i again increase the revs, which obviously makes me go faster than i should be doing. THis happens when the engines cold and hot.
im afraid that my mechanical knowledge is minimal, so please talk to me as though im stupid. :)
thanks in advance.
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