Too much fuel

[Gremlyn]

I have a 20v silver top in an AE92. The conversion was done about 2 years ago. The car has always run a little rich but recently the engine is getting way to much fuel and fouls the plugs. I am unable to drive it any where as it just splatters and then dies out.

The car will idle when the AFM is unplugged but still runs rich but is drivable in first gear as long as you don’t get to heavy on the accelerator. As soon as the AFM is plugged in it stalls out.

Should note that it is blowing black smoke.

I have changed the AFM, no change and as it will idle with out the AFM I have ruled out leaking injectors.

Has any one had similar problems or have any suggestions on where to look next

[ViPeR_NiPPleX]

checked ecu for codes?

[Gremlyn]

The diagnostic plug doesn’t work, I have been informed that you cant get any codes from the 20v.

[ViPeR_NiPPleX]

that sounds like crazy whack talk to me.... feck the diagnostic plug if its shagged... just go straight to the ecu connectors

[slide86]

how bout faulty coolant temp sensor? that might be sending a message to the ecu that the coolant temp is cold, this would then richen up the mixture ie cold start conditions.

How bout the O2 sensor? false reading from the exhaust may say that the engine is running lean and try to correct it with increased fueling....

Apart from these two sensors and the AFM, there isnt much more that controls mixtures (that i can think of at the moment) apart from the ECU of course.
People more than welcome to jog my memory

Check these out and see how you go.

[30psi 4agte]

Tend to agree with slide 86. Could be o2 or coolant temp sensor.
Another one to think of is fuel pressure. Faulty pressure reg or blocked/crimped return line.

[CrUZida]

Does the 20V run a vane/flap type AFM?

[mullett]

I take it that this is an AFM silvertop? Maybe the injectors are knackerd, pull them and get them cleaned. Apart from that, get a jaycar A/F adjuster one you get this problem sorted, and get it tuned. I just finished building mine, great bit of kit.

RM.

[mrshin]

Sure it's not just a busted wire?

[ViPeR_NiPPleX]

i wouldnt use an interceptor to try and solve the problem assuming nothing has been changed...

broken wire is possible eh

[Gremlyn]

Thanks for the tips, i will check them out this afternoon and get back to you all if problem fixed.

Cheers...

[wilbo666]

how bout faulty coolant temp sensor? that might be sending a message to the ecu that the coolant temp is cold, this would then richen up the mixture ie cold start conditions.

That sounds like an excelent thing to check IMHO.

How bout the O2 sensor? false reading from the exhaust may say that the engine is running lean and try to correct it with increased fueling....

The O2 can only adjust 15% max or a small value such as that, I don't think that would be enough to cause the symptoms put forward here.

Oh and fix your diag plug, you should be able to get codes out of a 20V.

Cheers
Wilbo

[CrUZida]

Does the 20V run a vane/flap type AFM?

. .

[Gremlyn]

It runs a flap type AFM

[CrUZida]

Thanks,

Well there is your reason why it stalls when you unplug it.
The AFM is what keeps the fuel pump running.
You unplug the AFM, and the pump stops, and the motor will eventually stall.

So my money would be on injectors leaking.
Get them serviced.