Earthing the intake manifold even though it looks properly earthed

R

Rev

Member +
I have been tracking idle issues for years improving gradually including removing aluminium oxide ( white powder ) discovered on the intake manifold earth bolt thread.
Cleaning the bolt thread made an improvement but after a short time even with the bolt sealed very tight the poor idle and white powder returned. ( I should add I live near moist salt air so it happens faster for me ) and maybe i should have cleaned the thread inside the manifold as well but it doesnt matter as I put a separate earth wire from the battery negative to the earth bolt on the manifold and the car has never performed better.

So just because all the wires look good it doesnt mean you are getting the best performance you could as this earth directly effects your injectors performance.

Before when the car started it was on the turbo timer ie running on battery only the engine revs dropped very noticably when all four blinkers flashed, now you can't hear the engine revs drop at all.

So if your if your engine revs on idle are sensitive to current draw think about a new earth and enjoy
a very responsive car when you put your foot down. :)
 
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dac69er

dac69er

Super Moderator
moist air, come to the uk ;)

good grounding can make all the difference. even with the ground on the intake manifold made off really well, if the intake manifold itself has a poor connection to ground, then it wont help.

a plan for when the rain stops is to add some extra ground points to mine.
 
R

Rev

Member +
dac69er said:
moist air, come to the uk ;)
if the intake manifold itself has a poor connection to ground, then it wont help.
Click to expand...

I don't know the full situation but think some grounds will be ok eg. the earth wires for the injectors go directly to the bolt I made sure the new earth contact touched these wires without going through the manifold , just squeezed them together with the manifold bolt.

Also I made my own earths with high grade copper ,and not as thick and heavy as some kits you see ( 8mm , 60 amp I think it was).

I am also hoping to check the other grounds over time too eg. wonder which earth is best for a healthy knock sensor reading.
 
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J

japakos

Member +
I'd recommend that to everyone here. I put some heavy gauge wire and run it to different places to have ground everywhere as I was running out of options because my car was bogging down and did anything you can imagine. Every single problem I had disappeared. It's like I bought a new car no joke here. DO THAT mates!
 
5e colin

5e colin

Member +
great thinking there
next time use copper grease with it it will never oxidate again and improve conductivity
 
rb69

rb69

Member +
So all we really need is some proper connections from the - terminal to any grounding points in the bay? Will this make much of a difference even to a pretty standard Starlet?
 
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G

GP82

Member +
So you got the extra earthing point to the inlet manifiold where the injector earth is, then the gearbox earth, what other points in the engine bay would you benefit from extra earths?
 
dac69er

dac69er

Super Moderator
it can make quite a noticeable difference. it tends to be in regards to idling, starting and the use of electrics in the car.

just going round the standard grounding points can be enough. most people just buy a grounding kit and notice an improvement when simply going over the existing ones would have made as good an improvement anyway.

for the cost of a grounding kit (if you cant make one up yourself for free) it is definitely worth a go.
 
T

triple j

Member +
I got this for sale
IMG137_zpsd4a8b4d6.jpg
 
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