Poor running problem
Discussion
My '90 S2 has recently developed a running problem, it's very lumpy on idle, almost cutting out before the revs jump again and "kangaroo-ing". It's more noticable when the engine's hot. Any idea's as to what's the problem, reading other threads I'm thinking it's the throttle pot... if so, any ideas as to where to get one ASAP and cost?
Thanks chaps!
Thanks chaps!
wonderland said:
My '90 S2 has recently developed a running problem, it's very lumpy on idle, almost cutting out before the revs jump again and "kangaroo-ing". It's more noticable when the engine's hot. Any idea's as to what's the problem, reading other threads I'm thinking it's the throttle pot... if so, any ideas as to where to get one ASAP and cost?
Thanks chaps!
does sound like the standard TP symptoms. 2 options.
1. Go to Ford and get 2.9 direct replacement = £52 (or thereabouts) and breaks again within short period.
2. Contact TVR dealer and buy cerbera 4.2 TP for around £30 (or thereabouts) and fit meaning it will have a longer life.
Before you spend any money, test to see if it is the TP at fault:
www.tvrsseries.com/throttlepot/throttlepot.htm
www.tvrsseries.com/throttlepot/throttlepot.htm
chingers said:
Swapping out to a Cerbera unit sounds easy to fit are there any wiring mods required? I've just fitted a std Ford unit and had to do the plug change to fit the later spec. Next time (which is probably not too far away) I'd like to go for the Cerbera unit.
Chris P.
No wiring mods needed on my S1.5 - just plug 'n play (or is that plug 'n pray ??)
bugsy said:
I hate to put a spanner in the works but this need not necessarely be the throttle pot, there is an idle valve sensor that could give you these problems.
I would personally plug my car into a ford computer to see what fault codes came up before I wasted my money.
or unplug the TP and see if the "get home" setup runs the car ok
Throttle pot problems on mine never showed on the diagonistics (at least my crude light bulb connected to ECU and counting the flashes...).
I don't think it goes out of range, just 'noisey', think it may be down to oxidation of the wiper or track exacerbated by the heat.
As said earlier easiest test is to unplug and see if the problem goes away.
I don't think it goes out of range, just 'noisey', think it may be down to oxidation of the wiper or track exacerbated by the heat.
As said earlier easiest test is to unplug and see if the problem goes away.
Well... I got the new throttle pot anyway 'cos the original part looked like it had been there forever and still the problem remains... gutted! The car accelerates smoothly once up over 2,000 revs but on small throttle openings it's extremely lumpy and sounds like it's constantly backfiring... any ideas?
Sorry to hear that the infamous TP did not resolve the problem.
Where to go next ???
As bugsy points out, the idle sensor may be worth a look. After that - coil, leads, dizzy cap, rotor......
Any mechanics local to you who are very familiar with the Ford 2.9 V6 and its 'characteristics' ??
Happy hunting (no pun intended).
Where to go next ???
As bugsy points out, the idle sensor may be worth a look. After that - coil, leads, dizzy cap, rotor......
Any mechanics local to you who are very familiar with the Ford 2.9 V6 and its 'characteristics' ??
Happy hunting (no pun intended).
Right... here goes:
Idle speed - normal at <1000 rpm. But it does start to fail and lose it before it jumps back and settles at normal speed again
Front wiring loom looks OK, no visible damage
Think it is running rich, lots of bangs and pops and smells of petrol
Pick up from idle is crap, very lumpy and jerky until after about 2000 rpm
Disconnect TP is virtually the same, replaced because the old one looked knackered anyway
Haven't disconnected air bypass valve - what is it and what does it look like (sorry for ignorance!)
Idle speed - normal at <1000 rpm. But it does start to fail and lose it before it jumps back and settles at normal speed again
Front wiring loom looks OK, no visible damage
Think it is running rich, lots of bangs and pops and smells of petrol
Pick up from idle is crap, very lumpy and jerky until after about 2000 rpm
Disconnect TP is virtually the same, replaced because the old one looked knackered anyway
Haven't disconnected air bypass valve - what is it and what does it look like (sorry for ignorance!)
Ok
If you want to sort this yourself, you have all the ticks in the boxes for either the auxilary air control device sticking or Knackered, you can clean this apparantly but if it's internal, you will also have to replace it.
The other option which will also give overich mixture and that is the thermotime switch pumping in extra fuel when not needed and you may have to replace it.
If you want to sort this yourself, you have all the ticks in the boxes for either the auxilary air control device sticking or Knackered, you can clean this apparantly but if it's internal, you will also have to replace it.
The other option which will also give overich mixture and that is the thermotime switch pumping in extra fuel when not needed and you may have to replace it.
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