Poor acceleration on my S1

[ed666]

Since I've had the S1, I've been going through a process of elimination to get its running sorted. ie Plugs, plug leads, distributor cap, fuel filter and finally fuel pump.
Its destroyed two fuel pump relays too!!
Now... the cold starting is difficult, doesnt want to run reasonably until well warmed up. Seems like the 'Kaltstart' relay is faulty, open circuits everywhere and a compnent thats fallen off the circuit board.
That all said, the acceleration seems to me quite slow, with a reluctance to rev much above 4000rpm. The previous owner didnt really use the car and I wonder if that has contributed to the problem. I would have expected this car to have been quicker off the mark than my previous car, a Mondeo 2.5V6, but it aint. Help!!

[Le TVR]

Hmm, destroying fuel pump relays sounds like an iffy pump or intermittent connections to it.
The kaltstart relay can usually be removed without noticing any difference!
Topping out around 4k suggests (IMHO of course)lack of fuel pressure or lack of spark energy.
Don't forget to check warm-up regulator, and ignition ballast resistor too.

Good luck

[ed666]

Thanks for that!
Any idea where the ballast resistor is?

[Ali B]

my ballast resistor is on passenger side of engine bay between ignition module and exhaust/top wishbone area, bound up in the bit of loom which heads off around front of engine.
it is light grey 5mm diameter and folded in thirds
of course, yours may be nothing like this!!

[Birchy]

I would suggest one of the following:-

The Kalt Start Relay simply ends an electircal current to the cold start jet if a sensor fitted next to the warm up regulator says the water is less than 30oc. If the sensor is faulty then the kalt start is on permanately as is the cold start injector effectively enriching your mixture beyond comprehension. It will feel like you have hit the rev limitor at or around 2500-4000 RPM. A stcuk kalt start relay will give the same sysmtoms.

Secondly, the warm up regulator contains a biametalic strip which reacts to the water temperature progressively reducing the mixture enricment. If it is faulty then you mixture will be to rich gagging the engine under load.

The air intake has a sort of valve that opens at a rate equivilant to the throttle opening. This can stick if not used regularily and requires freeing and lubricating. Effectively, it will not open sufficiently again over enriching the mixture giving the systoms you described.

Given what you have done, try 3,1 2 since that is the order in which the expense will be incurred. Mine was simply a stuck kalt start relay which after a good clean has not returned for the last two month.