Help, -- Too rich on idle and to lean on boost

[boosted]

Hello,

Hopefully somone can point me in the right direction.

I'm helping a friend on his 1981 lancer Turbo, which is basically the same engine like the JA starions.

The thing is, on idle it's running a lambda /Afr of 0.85 / 12.5
and on boost it first starts to richen up a bit goes back to 14.7 and eventually goes to a Lambda 0.91 Afr 13.4. And this with only 0.5 Bar of boost (7.25 psi)

It also feel lean and doesn't pull freely.
A couple of years ago, we measured the lambda and was rich on load
Lambda 0.78 Afr 11.5 and that was with one bar of boost (14.5 psi).




I changed so far..

-measured fuel pressure, also on load.
-Thottre potentiometer
-Map sensor
-AFM
-ECU


Don't really know what could cause this....


As far as i know the main load used for injection is the AFM or is the Map sensor aswell a main load?


Any help, very welcome...


Cheers

[dirtygalant]

could there possibly be a manifold leak anywhere?

[redzone]

fuel pump, not enough flow. sometimes they will have enough pressure but not enough flow..

[boosted]

that could be a thing, but what also confuses me, is that in on idle it runns way too rich..

damn old ECI ;)

Will check further this evening..

[redzone]

does it have an idle mixture trimpot like an early starion?

[boosted]

Yes, thats on the same loom like the TPS sensor..
Do you think i should try to adjust that to a good mixture on idle? and check for the lean issue afterwards?

The strange thing, is i also changed that one with mine, which was for emmision test a couple of weeks ago and it's the same (way too rich).

What about these 2 white resistors, are they common to break? what would the affect be?

Cheers

[boosted]

i also forgot to mention, that the car also doesn`t make the overrun fuel cut off, how does that get activated?

[JPC]

The two white resistors are the in the power supply line to the injector solenoids. If these break, more than likely the car won't run at all. From memory, they should be 6 ohms.

[redzone]

yes i'd be adjusting the trimpot for the best idel then chasing your other problem :)

[boosted]

After 8 hours more of searching the problem, i'm stil at the same spot!!!

Checked and measured out nearly EVERYTHING, all fine and giving good read outs to the ECU.


Next to do..
-Check injectors
-check ALL grounds

The problem is still the same, running lean on WOT, 2 or 3 times we managed to see some better readings, towards AFR 12,4.. But wasn`t repeatable.

If theres no solution in the next (let's say) 5hours of searching, we'll probably rip the whole "ECI Sh..." out and go for a MPI.


Its' really frustrating not to know what causes this!!!

Time for a beer ;)

[panda]

I have seen in the past where an air/fuel ratio gauge read abnormal due to faulty O2 sensor in the exhaust. However, that motor was running fine.