Potentiometer -Flapper type EFI

[mike350]

I am sure that via these pages someone out there will know who is able to supply a replacement / or repair my throttle potentiometer ( I think thats how to spell it!)
Just recently on slowing down and on very light throttle the car misses and jerks badly. I have checked all normal things and when I wiggled the wires on the potentiometer the engine stuttered and all most stalled so I think this must be the route of my problems.
Thanks for any help.

[rev-erend]

Maybe it's the the contacts on the wires need re-soldering..

[mike350]

Thanks for reply but: No its not the connector, the iratic running only happens as you wiggle the wires at the point of them exiting from the potentiometer itself.

[gsx600]

Do you mean the throttle pot on the plenum, as if so I think I've got a couple of spares in my garage. Can't look untill friday as I'm in Bradford at mo and not in Reading

[wedg1e]

It's possible to cut away the back of the throttle pot and solder new wires in, if you REALLY get stuck...

[mike350]

If gsx600 could let me know if you have a spare potentiometer then I would be more than happy to reimbuse you.
Thanks.

[gsx600]

Where abouts are you mike, might be able to drop one off too you in my travels. Definately think have at least one from my spare engine, just need Dicky or Wedgie to remind us what to set it up too as I can't remember that after 4 bottle of sol on a hotel bed

[Gerry Attrick]

I got mine from a Range rover dealer a few years back. The cost was about £60. It took a while to get it so I did a repair for a while, as there are a couple of different types with varying numbers of bolt holes.

If you cut radially around the base of the pot, with a Junior hack saw, next to the shoulder, you can split the top from the bottom. You'll need to ensure the blade is no deeper than one quater of its depth, otherwise you'll cut into the contacts inside. When you've split the pot in half, you can see the contacts and track. Clean these up, with fine wet and dry, and re-solder if necessary. Smear a spot of grease on the tracks. A CD case is the same thickness as the saw cut so you can make a spacer / gasket from an old one using the pot base as a pattern. Bolt all three pieces together using a blob of hard plastic glue and "Robert's your mother's brother!"

[mike350]

Thanks Gerry for the info but without a spare I feel the risk would be too high. If I can obtain another one then I certainly will attempt to cut it open and investigate.

[gsx600]

Right I have 2 sitting in front of me, but both different,

1st 3 wires, yellow, red, green varible position- ie move it to get the correct set up voltage - DICKIE triangular type plug

2nd 3 wires blue, green, red with set position (no elongated holes), oblong connector plug

Which matches yours ?

I'll check them out on the multimeter if I get a chance this weekend

[wedg1e]

300mV +/- a bit is the figure you're looking for...

[dickymint]

325mV plus/minus 25mV says the SD1 EFI book. But then that is with the throttle plate closed. Wedges are set up with a slight gap (0.005"at idle so I would suggest 350mV as a starting point.

But then I could be totally wrong.........agian

[rev-erend]

Dickie - I'd agree but anyone with a hotwire - I think the throttle plate is firmly closed and has no gap.

[Gerry Attrick]

Paul, when you get out the multi-meter can you post the resistances between all three wires when open and closed, please. Comparing my set up; which I can't remember at the mo; it's different from that shown in the Bible etc. In other words when connected, the 325 mv is between a different pair of coloured wires than stated. Thanks. Don.

[mike350]

GSX600.
I'll just go and check to see which one I have but It will certainly be the first as I have slotted fixing points and a triangular connector, white, but not sure of the colours. I will e-mail you my address and confirmation.

To everyone else who has contributed, many thanks especially about setting up as I assumed that you just had to use trial and error to set it up, although I'm not too sure about testing for M/Volts but resistance would be no prob.

Thanks again.

[dickymint]

mike350 said:

GSX600.
I'll just go and check to see which one I have but It will certainly be the first as I have slotted fixing points and a triangular connector, white, but not sure of the colours. I will e-mail you my address and confirmation.

To everyone else who has contributed, many thanks especially about setting up as I assumed that you just had to use trial and error to set it up, although I'm not too sure about testing for M/Volts but resistance would be no prob.

Thanks again.

Put your meter on to DC Volts and check for 0.35 Volts

[gsx600]

Gerry Attrick said:

Paul, when you get out the multi-meter can you post the resistances between all three wires when open and closed, please. Comparing my set up; which I can't remember at the mo; it's different from that shown in the Bible etc. In other words when connected, the 325 mv is between a different pair of coloured wires than stated. Thanks. Don.

Hopefully do this tomorrow for you Don, if I'm not hooning it at around 14.00 as apparently the roads might be a bit quiet due to some local event going on Sat

[gsx600]

Ok now checked the pots

Mine

Red & Green wires
.31v - 4.04v closed to full throttle
.67 K ohms - 6.09 k ohms

Spare to be posted monday
0v - 4.29 - closed to fully open, but not on car hence full range
0.12 k ohms - 6.09 k ohms

Othere spare with strange connector so could not get volts to it
Blue & green wires
0.22 - 5.8 K ohms

Hope that helps

Cheers

Paul

[Gerry Attrick]

Paul. Thanks for the info. I'll check it this evening. Been away in the Malverns and Devon for a long weekend and only got back last night. Just what the Wedge was bought for. Hood down - country lanes - sunshine - barbeques - theatre - beaches. Bliss !

[Gerry Attrick]

gsx600 said:

Ok now checked the pots

Mine

Red & Green wires
.31v - 4.04v closed to full throttle
.67 K ohms - 6.09 k ohms

Thanks Paul. Mine's the same. Set my mind at rest.