Idle all over the place after earth mod
29 September 2007, 09:14 PM
#1
Idle all over the place after earth mod
I fancied a bit of tinkering under the bonnet today so I decided to carry out the earthing modification.
Got some good quality cable and made a nice tidy job connecting all the following points back to the battery negative.
ECU bracket, both struts, manifold and block (5 points).
When I took the car out for a run I felt a slight hesitation when cruising at 60 when I pulled up at lights, the idle swung from 0 RPM to 1000 RPM. Just before the lights change it settled back to 900 RPM. Each time the car idles, after a few seconds the same thing occurs.
The car starts fine, accelerates fine and feels as strong as it always has. I have checked for fault codes but there was nothing shown, I checked with my SECS unit for fault codes and it returned nothing either.
Any suggestions. Car is 2001 classic with 55,000 miles.
TT
Got some good quality cable and made a nice tidy job connecting all the following points back to the battery negative.
ECU bracket, both struts, manifold and block (5 points).
When I took the car out for a run I felt a slight hesitation when cruising at 60 when I pulled up at lights, the idle swung from 0 RPM to 1000 RPM. Just before the lights change it settled back to 900 RPM. Each time the car idles, after a few seconds the same thing occurs.
The car starts fine, accelerates fine and feels as strong as it always has. I have checked for fault codes but there was nothing shown, I checked with my SECS unit for fault codes and it returned nothing either.
Any suggestions. Car is 2001 classic with 55,000 miles.
TT
Last edited by tarmac terror; 29 September 2007 at 09:16 PM. Reason: typos
29 September 2007, 10:00 PM
#2
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Late classic ? Wobbly idle after disconnecting battery ?
Likely the MAF sensor. It has to be totally fubar before it throws a code.
If your secs can plot the voltage it should max out at ~ 4.6v under load.
Likely the MAF sensor. It has to be totally fubar before it throws a code.
If your secs can plot the voltage it should max out at ~ 4.6v under load.
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30 September 2007, 05:50 PM
#5
Rigga - did that, new terminals are connected to the original battery negative connector by the bolt. Removed and cleaned the original earth points too.
Not 100% sure it is the MAF, need to try disconnecting it to see if it affects the running. Leaning towrds it being the Lambda probe.
TT
Not 100% sure it is the MAF, need to try disconnecting it to see if it affects the running. Leaning towrds it being the Lambda probe.
TT
01 October 2007, 01:28 PM
#6
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I did earthing kit the other weekend, def had a change in restistance over engine components to earth but not much difference in running although I'm sure the starting was a little faster.
Interested in the fact you did the ECU earth - is that a known "bad" earth on classic and new age cars?
Interested in the fact you did the ECU earth - is that a known "bad" earth on classic and new age cars?
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