2.8i Overfuelling issues

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gaz7952
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2.8i Overfuelling issues

Postby gaz7952 » Sat Apr 06, 2019 6:21 am

Hi All,

I have an overfuelling issue with my 2.8i all of the plugs are carboning up and it runs terribly warm or cold (ran it for 30 mins). It has been stood on and off for 12 years. So far I have done the following:

1. Checked the ignition system all ok new plugs, leads and coil.
2. New fuel (98 octane + Valvemaster plus)
3. New fuel filter
4. Checked operation of throttle butterfly
5. Checked the plunger in the metering head operates ok by moving the diaphragm plate up and down.

So where to next I want to try and follow the fuel path. Any help greatly appreciated.

Cheers Gaz

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Andrew 2.8i
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Re: 2.8i Overfuelling issues

Postby Andrew 2.8i » Sat Apr 06, 2019 7:29 am

Hi Gaz,
I find the info on this website very useful for troubleshooting:
https://www.zeepoort.nl/jetronic/K-Jetr ... oting.html

:goodluck:

Andrew.
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Peter-S
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Re: 2.8i Overfuelling issues

Postby Peter-S » Sat Apr 06, 2019 4:37 pm

gaz7952 wrote:Hi All,

I have an overfuelling issue with my 2.8i all of the plugs are carboning up and it runs terribly warm or cold (ran it for 30 mins). It has been stood on and off for 12 years. So far I have done the following:

1. Checked the ignition system all ok new plugs, leads and coil.
2. New fuel (98 octane + Valvemaster plus)
3. New fuel filter
4. Checked operation of throttle butterfly
5. Checked the plunger in the metering head operates ok by moving the diaphragm plate up and down.

So where to next I want to try and follow the fuel path. Any help greatly appreciated.

Cheers Gaz


When you say you have checked the plunger moves are you sure it does? Just because the air sensor plate moves freely it doesn't mean the plunger is. If you lift the air plate quickly up you might detect the plunger drop down a second later but if you are not certain then really you need to take the metering head off and check and clean the plunger if necessary.

You could also try disconnecting the 7th injector electrical connector (left side of the plenum as you stand in front of the car) in case it is running constantly.
The warm up regulator could also be an issue as it allows a richer mixture on cold start up and should restrict the flow as the engine warms up although if you have the problem from cold this seems an unlikely culprit.
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Caprifan Rob
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Re: 2.8i Overfuelling issues

Postby Caprifan Rob » Sun Apr 07, 2019 5:09 pm

Peter-S wrote:
gaz7952 wrote:Hi All,

I have an overfuelling issue with my 2.8i all of the plugs are carboning up and it runs terribly warm or cold (ran it for 30 mins).



You could also try disconnecting the 7th injector electrical connector (left side of the plenum as you stand in front of the car) in case it is running constantly.

I had this problem when I first had mine. It’s permanently disconnected now & ive had no further issues. It’s worth trying first as it’s so easy to disconnect before you start eliminating anything else.