running lean

[roybaser]

hi to all ive not had my pulsar long and it seems like ive sorted 99% of the crap work the old owner gave me
i have put in a innovate afr gauge its reading all fine when your on the move 14 ish middle of the gauge.but on idal its 22.5 of the gauge is this normal?
ive changed

vac hoses
maf
lamb
could it be the standard fpr has died

thank mick

 

[Metcallf]

I had the same problem a few weeks back, its turned out for me that was fuel pump was knackered

 

[roybaser]

when i got the car it had a new pump a sytec one but he never told me how old it is. so cant rule it out but dont think its that. thanx for the reply

 

[PobodY]

It will be reasonably high on idle; I don't know that it should be that lean. - There's no load on the engine at idle, so there's no need to throw fuel at it so you can have a stiochiometric burn; I'd guess it should read about 15.

When you're on the power it should be reading more rich than 14; probably about 12 getting progressively more rich as you approach WOT to give you some protection against DET.

 

[campbellju]

It might be lean at idle but I'd be surprised if it was that lean. If the reading were true you'd get a lot of lean misfires.

Is it idling okay or does it sound rough?

Maybe their is a reading issue? Where is the sensor located? Could you be getting air leakage at idle but once moving the dilution effect is much reduced so the afr's become normal?

 

[MarkTurbo]

It might be lean at idle but I'd be surprised if it was that lean. If the reading were true you'd get a lot of lean misfires.

I had a play around with idle afrs once when I was bored and i'm pretty sure mine is nearly stalling at 19/20 afr at idle and sounds pretty rough so I'd be surprised if it really was that lean. Sounds like it's reading ok if you're getting 14 when cruising, did you do the free air calibration properly?

 

[roybaser]

just changed the pump no change at all
the lab for the afr gauge is in the de cat pipe and ive set it up 4 times and still no change

 

[roybaser]

oh and if i un plug the lamb plug it dose not change a thing its got power ect
thanx for the help so far

 

[geoff pine]

You need to change the sensor or better still try a different make of wide band I had one the same make as yours it lasted 3 months and very little mileage before it just stopped working .

 

[campbellju]

How is the car running at idle? At 22.5 it wouldn't run continuosly. Misifres can cause lean readings as the unburnt mixture has not burnt the oxygen. Again if your car was continuously misfiring you'd know about it.

If your car is idling smoothly, no smell of petrol and your plugs look normal then it's more likely to be a measurement issue. Doesn't mean it's faulty just means it's likely an incorrect reading and you need to find out why. Air leak, electrical noise, wiring fault, sensor fault, meter fault etc.

 

[PobodY]

Does the innovate require you to fit a capacitor across two of the wires, or is that only if you're trying to use it to emulate a narrow-band lambda signal?
I'm just wondering if it's a base-line correction (so it's always out by ~2 for example).

 

[fubar andy]

Also check your injectors, make sure they are not faulty.

I had a problem with mine going lean as one was not working correctly. You can listen to them by sticking a screwdriver on to the injector (while the engine is running) and then put your ear to the bottom handle of the screw driver.

You should hear a regular ticking noise (the sound is transmitted up via the screwdriver) if one of them sounds different, that might be the cause?


...Just an idea?