[Sc0tt]

Hi

I have a 16V 33 and I had a similar problem where after I cleaned the tracks in the AFM my car over fueled to the extreme and would hardly start, let alone run. For me it turned out that as the car wore and things became dirty the PO's mechanic would adjust the CO2 pot on the side of the AFM to keep everything running ok. When I went through and cleaned everything this setting was now way, way out. I can't for the life of me remember which of the wires out of the AFM to watch but you need to set this CO2 pot to read around 2.5V. Mine was about 4V. You should be able to just back probe the connector til you find the right ones.

After doing this and the usual maintenance I now get 7.6l/100km in heavy stop start highway traffic. Pretty happy with that.

cheers
Scott

 

[Sc0tt]

Hi

On the 16V 33 moving the distributor has no effect until you go too far, then no more spark. Go even further and then you will start sparking on the wrong cylinder. The dizzy in the 16V basically has nothing to do with timing. All aspects of timing are controlled by the ECU. The dizzy simply aligns the rotor to the right plug. The rotor has a rather large contact area on it so that as long as it is pointing roughly in the right direction, it will spark fine.

Moving the dizzy has no effect as the dizzy does not trigger the spark (through points or contacts) it is all done off the hall effect sensor attached to the fly wheel.

You should see a screw on the side of the AFM to the right of the wiring connector. This is the CO adjustment. Try moving it 2 turns in, then two turns out to see if it makes a difference. This is the adjustment I was talking about. If it ever stops raining here I will go out and check which pins to use so you can make sure yours is set at 2.5V.

The other thing is to make sure you have absolutely no air leaks. The Motronic system is very susceptible to air leaks. Just not having the dipstick seated fully can cause a lean mixture and make your engine ping. Weird but true as on the elbow of the intake between the AFM and the plenum is a line that runs to the oil filler. If the dipstick isn't seated you allow more air to flow through than is expected and voila, lean mixture.

cheers
Scott

 

[Sc0tt]

Hi

For me it made a lot of difference. If I recall mine was reading 4(?)Volts and would only just start, but would not run. At 2.5V it runs sweet as a nut.

Of course this is only a supposition that you could have a similar issue. Have you ruled out the other "basics" such as fuel filter, air filter, plugs, leads, air leaks, bad fuel and compression test.

What do your plugs look like? Have you put an Ohm meter across the leads (more than 1k Ohm per inch of lead and I would replace. Have you tested the primary and secondary sides of the coil? Start spraying a WD40 or the like around all possible areas of ingress for air into the system and listen for a change in tone of the engine.

How clean are your injectors? There is a video of cleaning the bosch injectors at home which I have used and it seemed to work great (I didn't get them flow tested afterwards so I can only speculate on seat of the pants feel).

Another thing to try is the fuel quality plug. You should have a plug, yellow or red "relay". Try removing the relay altogether. This is how I run my car now. It gives the most advance and ignores the O2 sensor (speculated see 'craigs place').

At least if you do the basics you have a known good base line to start from.

cheers
Scott

 

[Sc0tt]

Hi

I found the link, which funnily enough was on this website....

http://www.alfabb.com/bb/forums/164-168-1991-1995/158079-91-93-afm-testing-pinouts.html

What you want is about 3/4's down.

cheers
Scott

 

[Sc0tt]

Alfa33boxer, the fuel quality relay is on Motronic equipped cars only.

Patanga, on my car the cut out on the dizzy is closer to where your rotor is sitting from memory. That picture doesn't tell a lot unless you are at TDC on number 1. Can you rotate the engine to TDC and take the pic again? We can then see if you are maybe too far out of position to get good reliable spark.

The video on cleaning the bosch injectors is found at

They are a simple on/off switch, not like the TPS on most other vehicles. I can't remember if they are on or off when closed. If you check for resistance as you open the throttle as long as it changes state (ie goes from open circuit to closed circuit or vise-versa) you should be ok. I think the TPS just controls the fuel cut at throttle close above 1200rpm. Not sure how else it is used and what other effects it would have.

cheers
Scott

 

[Sc0tt]

Hey, cool, the video appeared instead of the link.

I mean, I meant that to happen.

cheers
Scott