Bidju

I have begun an epic journey of trouble-shooting an EA I just purchased.

The problem is it's using about 20-25 litres of fuel per 100km in city driving, where it SHOULD use about 14-15 max and 10L/100k on the highway.

I have replaced any leaking vacuum tubes, plugs look good, injectors have been flushed, it appears to have a brand new O2 sensor. It has weird high idle happenings even at operating temperature, although I've read the CPI EAs will do 61km/h at idle.

A mechanic ran the onboard diagnostics and it came up with a faulty MAP sensor. He ran it a second time and it came up good. A new one was installed it worked for a while (a few seconds) then went back to running too rich.

The manifold pressure was tested ok, so no leaks supposedly. However the fuel pressure was way too low indicating a blocked filter or a dead pump.

Looking into the throat of the intake manifold, is the fuel meant to splurt lazily out of the injectors in large droplets and splash onto the throttle butterflies and pool around for a while then finally over the edges into the manifold? Or is it meant to spray out of the injectors in a fine mist?

One theory I have come up with is that with the low fuel pressure, the fuel isnt atomising properly and the ECU is compensating by pulsing the injectors more.

I'm also suspecting an O2 sensor fault, or perhaps the wiring is causing a wrong reading due to faulty wiring. I'm not suspecting thermostat or temperature sensor faults at this stage as the temperature gauge reads normal operating temp and the engine fan kicks in, although there is the weird high idle problem that occurs at times.

Any thoughts?

Axeman82

I am assuming its a 3spd? Well sorry to disappoint but if it is then there is really no way to get 10L/100kms on the highway - it's just not going to happen, not in the real world. I average 14L/100kms on a good day which is mostly country driving and I admit I am not the softest driver out there but I don't flog it either.

If its a manual then you may get close to those figures and with a 4spd you'll probably be a little short of them. Depending on your driving style.

If the fuel pressure is low then when you sink the boot in, the car won't be able to supply enough fuel and it will die. This is exemplified by people doing MPFI conversions and not changing the fuel pump (just an example - doesn't apply in your case).

How old/what condition are the leads/dizzy/rotor button?

High idle can be due to a faulty throttle position sensor (TPS). A blocked catalytic convertor can also lead to poor fuel economy and other running issues.

I probably haven't helped much.

Daniel..

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Bidju

It's a 4 speed. I got about 160Ks out of 40L of Sloptimax. CRIKEY!

Bidju

I ran the self diagnostics today and heres the results:

Key On Engine Off:
(same result for cold engine and running temperature)
22 - MAP sensor out of range
63 - Throttle sensor voltage too low
(closed throttle)

Key On Engine Running:
(cold engine)
21 - ECT Sensor out of range
(running temperature)
Test OK

Symptoms are blowing black smoke all the time, and only getting 160km out of 40L of premium. Intermittantly idles high when engine is at operating temperature, has stalled going down a hill once in 3 weeks. Otherwise idles and drives well.

Any ideas?

Bidju

I havent looked at the dizzy yet. It appears to have a new O2 sensor. A tuning place tried swapping in another MAP sensor but it still ran rich.

Walkinshaw

change your coolant temp sensor. Your car thinks its cold and is running rich to try and warm it up.

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Ive been described as a vault of usless random knowledge.

Ill take it as a complement i think.............

xfspacsix

I had the same sort of problem with my el. Try starting the car, unplug the map sensor and jam it back in hard and hold it there. You said you changed the map sensor and it worked for a few seconds, this could be because it slightly loosens and doesn't quite connect. When I had this problem I immediately looked at that plug and saw it was in so I didn't know what else to check, (I was in phillip island on my way how when this happened) I took the car to the mechanic and found that it was the map sensor and he had to glue it in place, 10 months later and my car is still fine.

Bidju

Ah... what did he glue in place? the electrical connector or the vacuum hose? I replaced the hose with a new one... I'll investigate

Bidju

Yeah I'll try tampering with the temperature sensor... maybe it's giving a bad reading

xfspacsix

It was the connector, it was "clicked in" but just didn't sit in there enough to properly connect.