Throttle Pot.. *groans* how much and where from?
Discussion
"The Throttle Pot has gone dear" I casually said to my better half as I struggled to control my wildly lurching S2 down a straight road last night.
"Its a very common problem on S2's. I've read about it so many times, from other owners, on the web. I was always wondering when my one would go. I'll get a new one in the morning and everything will be fine" I tried to explain.
Anyway, today I went to my local motor factor, armed with the motoquip part numbers people had so kindly posted here, but they didn't have and were unable to order one for me.
So, can anyone tell me where I can get one of these? I do not mind if its the gold Ford or Cerb part, plus the wiring mod. Some idea of the price would also be useful.
"Its a very common problem on S2's. I've read about it so many times, from other owners, on the web. I was always wondering when my one would go. I'll get a new one in the morning and everything will be fine" I tried to explain.
Anyway, today I went to my local motor factor, armed with the motoquip part numbers people had so kindly posted here, but they didn't have and were unable to order one for me.
So, can anyone tell me where I can get one of these? I do not mind if its the gold Ford or Cerb part, plus the wiring mod. Some idea of the price would also be useful.
Throttle pots from a Ford dealer will set you back about £50 and they will tell you to get the new gold connectors as well. I spoke with Mike at Austec a while back and he said the part number on the Cerbera TP is the same as the S but costs half the price. There are 2 for the cerbera so you need the right one. I ordered mine from Castle TVR and had it within 2 days. Should say that I have an S3 so I don't know if it's any different to yours.
esmyth said:
Crebera 4.2 TP is about £22 from local TVR dealer - part number E1586 (I think) - generally regarded as a better replacement
That's the one!
Although myself, F908TIM and others have noticed a less lively throttle response using this one but at least it's reliable!
I have a different one to standard (not the cerbie one) fitted at the moment. I'll post up the part number when I can get time to go have a look. There are several Ford ones too!
NickP_S2 said:
"The Throttle Pot has gone dear" I casually said to my better half as I struggled to control my wildly lurching S2 down a straight road last night.
"Its a very common problem on S2's. I've read about it so many times, from other owners, on the web. I was always wondering when my one would go. I'll get a new one in the morning and everything will be fine" I tried to explain.
Anyway, today I went to my local motor factor, armed with the motoquip part numbers people had so kindly posted here, but they didn't have and were unable to order one for me.
So, can anyone tell me where I can get one of these? I do not mind if its the gold Ford or Cerb part, plus the wiring mod. Some idea of the price would also be useful.
Disconnect the pot in the interim. This will put the car into a "get me home" mode - which runs a little richer but without the lurching ! Obviously if the lurching doesn't stop - then it also proves that the problem is not the throttle pot and something else instead ...
Hoover33 said:
I've got a cerbie throttle pot.... if anyone is afterone.
I tried it and was not impressed by it. It has covered approx 10 miles.
Make us sensible offer and you can have it.
Likewise on the unimpressed - although for the £20 it cost I'll probably keep mine in the glovebox as a spare.
GreenV8S said:
Hoover33 said:
I tried it and was not impressed by it. It has covered approx 10 miles.
Anything particularly wrong with it, or did it just not cure the problem you had?
With Cerb TP, mine ran rich and lumpy as hell with the outer wires one way round (popped and banged on overrun like a fireworks display) and ran a bit flat with them swapped.
More worryingly though was that at full throttle position, the engine cut out briefly with the Cerb TP in place. I was guessing this could have been due to a returned resistance value that the ECU could not interpret and it just cut everything ??
Mine definitely runs better with the original Ford TP, although the following symptoms are starting to appear:
runs rough for first 5 minutes after not being started for a few days.
tickover sets itself to 1200rpm when warm (this is rectified by turning the engine off and back on again).
Maybe I have issues other than of than the TP ?
>> Edited by SotonS2 on Monday 14th February 12:45
GreenV8S said:
Maybe I have issues other than of than the TP ?
Does sound like it. Maybe it's due for a service?
Ironically, she's just had one. New leads, cap, rotor, plugs, oil, filter etc etc.
The only 'service' item not replaced was the air filter although this looks like it has hardly seen any use.
More investigating required then...
Throttle pots are becoming the bane of my life at the moment 
As of last night, I am back on the Cerb TP. She runs sweeter (particularly from cold) than either of the Ford TPs I have, both of which seem to have gone duff.
I still have the problem of the engine cutting out at max throttle position though. Rather than spend another £22 or £50 on a fourth TP, I am seriously considering making an ECU reader. Once I get the pinouts for the ECU, they only seem to consist of a switch, an LED and a current limiting resistor. At least this way the ECU can tell me what IT thinks is wrong !
Whilst on the subject, does anyone know what the output characteristics of the TP are supposed to be ?
I hooked up a Ford TP to a 5v power supply and did some measurements. With the TP spindle hole facing you, Pin 1=left, Pin 2=centre and Pin 3=right.
I reckon:
Pin 1 = +5v
Pin 2 = ground
Pin 3 = Vout
At throttle closed, Vout = 110mV
This rises steadily to about 3v at 95% throttle open.
Above 95%, Vout 'jumps' to 4.5v.
Does this sound about right or is 4.5v above the max voltage the ECU expects to see ?
Oh, and for reference, both the Cerb and Ford TPs measure between 3.9k ohms and 180 ohms from throttle closed to fully open.
Will update as and when.
As of last night, I am back on the Cerb TP. She runs sweeter (particularly from cold) than either of the Ford TPs I have, both of which seem to have gone duff.
I still have the problem of the engine cutting out at max throttle position though. Rather than spend another £22 or £50 on a fourth TP, I am seriously considering making an ECU reader. Once I get the pinouts for the ECU, they only seem to consist of a switch, an LED and a current limiting resistor. At least this way the ECU can tell me what IT thinks is wrong !
Whilst on the subject, does anyone know what the output characteristics of the TP are supposed to be ?
I hooked up a Ford TP to a 5v power supply and did some measurements. With the TP spindle hole facing you, Pin 1=left, Pin 2=centre and Pin 3=right.
I reckon:
Pin 1 = +5v
Pin 2 = ground
Pin 3 = Vout
At throttle closed, Vout = 110mV
This rises steadily to about 3v at 95% throttle open.
Above 95%, Vout 'jumps' to 4.5v.
Does this sound about right or is 4.5v above the max voltage the ECU expects to see ?
Oh, and for reference, both the Cerb and Ford TPs measure between 3.9k ohms and 180 ohms from throttle closed to fully open.
Will update as and when.
GreenV8S said:
Don't know the numbers for that ECU, but I don't think jumping is ever right.
Neither do I - I assumed the TP would have a linear rather than 'stepped' output ! If its an exponential output, its a mighty steep slope over the last 10% of throttle travel.
I did a bit of net trawling last night looking for TP output graphs but didn't come up with much. Will have another look tonight.
Your are correct.... the Cerbie 4.2 TP is a ford part..... IMHO not the right one for the S.
Yes, it sort out lumpy running when cold....but
Hestenancy when throttle appilied at low revs, and no where near are responsive at top end of rev counter. All the "fizz" seemed to dispaear.... if you know what I mean.
Yes, it sort out lumpy running when cold....but
Hestenancy when throttle appilied at low revs, and no where near are responsive at top end of rev counter. All the "fizz" seemed to dispaear.... if you know what I mean.
Yup, both TPs are Ford parts but have different part numbers stamped on them.
Checking the resistance values (albeit on suspected duff TPs) suggests they are in the same ball park but not identical.
I haven't checked the voltage output of the Cerb TP - that one's bolted on the car at the moment.
It seems some S ECUs cope fine with the Cerb TP, others do not - bizarre, I know. But then that's TVR for you
Checking the resistance values (albeit on suspected duff TPs) suggests they are in the same ball park but not identical.
I haven't checked the voltage output of the Cerb TP - that one's bolted on the car at the moment.
It seems some S ECUs cope fine with the Cerb TP, others do not - bizarre, I know. But then that's TVR for you
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