6 replies to this topic

[Buckles23]

Hey, 

 

I've had a few issues with the old Spi. Initial issues where that if failed its emissions with a high o2 and believe the car to be running rich or just not running like it should. a little sluggish. 

 

I managed to setup Memsfcr so that i could have a closer look and see if i can find out whats happening

 

Here's what i have noticed so far and any help and detail as to how i might get it running nice would be great. 

 

 

On start up i seem to be getting this fault appear 

 

 02 fault shortly after start from cold.PNG   59.24K   5 downloads

 

However the Lambda voltage is going up and down as you can see on the graph and the Loop status is closed, which i believe is the correct process. This all happens before the car gets to any kinda running temp.  Can the sensor do this but the heater element to the sensor is broken therefore causing the fault ??

 

Here's a look at some of the data as its warms up with this fault already flagged

 

 Warming up.PNG   107.98K   8 downloads

 

Not sure if anyone can see what might be going on. 

 

 

Some other things i've noticed

 

Temp is only reaching 81 at idle and also after a quick blast up and down the road it remains at 81/2 .. Is this a case of just replacing the thermostat?? to see if it increases the temp. 

 

I checked the Heater relay by switching on and off and can hear the click of the relay

 

If i rev the car the Lambda voltage flags as a red high reading and Loop jumps to open for a moment or 2 (I can add chart if it helps) 

 

 

So really just wanting to know how i might resolve some of these issues and if i can provide any more info that might help to get the wee car running nice 

 

 

 

 

 

 

[sonscar]

If the water temp is too low it will still be running some warm up enrichment.88degrees is the magic figure I believe.Steve..

[Buckles23]

I have just checked the thermostat and surprise.. someone has used a 82 temp.. I have now replaced it with a 88 temp thermostat and waiting for sealant to dry before testing.

My basic understanding what might be happening is heater not working on lambda sensor and therefore resulting in a 02 fault and then car never reaching 88 temp so it never getting to run as it should.

If car able to get to 88 would that mean heater would turn off anyway and car would work as normal?

So short term emissions would be ok if car at 88 temp

[Buckles23]

Ok so Thermostat changed has raised the running Temp to the Magic 88

 

Here's a snap shot of the data

 

 Magic 88.PNG   117.03K   11 downloads

 

 

Only thing i am seeing now is when rev on and off then Lambda sensor gets a very short error, which causes the o2 fault to come back...  Is that normal or if not what might be causing this  ?? 

 

 tapping the rev.PNG   81.46K   11 downloads

[bergxu]

Weird, my ‘93 is getting the same fault. Voltage switches quickly but when you rev it and let the rpm then fall back to idle, it briefly drops the signal and will trigger an O2 sensor fault in MEMSFCR. This is with a fairly recent Bosch O2 sensor with not many miles on it…will be curious to see what you come up with. I was going to order a replacement but at the price they’re asking for them, figured I would wait to confirm

[Buckles23]

Yeah thought it was a little strange. I did replace the vacuum pipe from the metal pipes which run along the back of the rocker cover to the purge value as it had a crack in it. My thinking was this might effect the map readings if it had a leak. Haven’t re tested it yet to see if fault gone.. I also have a spare o2 sensor which I might change if I get the time to do it. If u find anything which helps then let us know

[R32Egor]

For information -

 

First read some of the guides regarding the SPI pinned ant the beginning of this section - loads of information and also tells you how things should be working - I know from 1st hand experience on getting and SPI running correctly (took me about 1 year in the end).

 

About the Lambda sensor -

 

The Sensor will be in *closed loop* after a certain amount of time after starting (people say it only does this at 88Degs, but my experience says this is not so it will go closed loop before reaching temperature) and will stay in closed loop at idle or only at steady cruise rpm. Outside of this criteria and the Lambda circuit will be in open status. ie -when blipping the throttle.

 

The lambda sensor its self works in hot temperature - so the heater for the sensor comes on when the car is cold and turns off at some point (cannot remember if this a time or a temp thing).

 

There is also information pinned that can show you how to test the sensor pretty easily.

 

good luck