Running lean

[ChrisLeeBoost]

Lads just checked diagnostics on the Glanza and got code 25 (lean air fuel ratio) is there any way or narrowing down the problem as there could be loads of reasons?

[satyrs]

check map sensor and lambda sensor. these will calculate the amount of air/fuel being used for the engine. if these check out correctly you could check for any vacuum leaks in the manifold. an extra dosis of air in the manifold could lean out the mixture.

or your fuel delivery system is to low. (broken injector, blocked fuel filter/line), broken FPR.

cheers,

wouter

[Bug679]

Just checking Google came across this seems it was an Earth on the throttle body for this lad , but as you say it could be any amount of things never heard of it before now 😬 Could have a leak somewhere before the o2 sensor causing It to not read the a/f correctly? Or a leak in one of your vacuum pipes maybe

Hopefully someone can point you in the right direction 😀

http://www.toyotanation.com/forum/59-tercel-paseo-starlet-sera-forum/72614-92-paseo-check-engine-code-25-running-too-lean.html#/forumsite/20543/topics/72614?page=1

[ChrisLeeBoost]

Had a look around engine bay and noticed that my screamer has burnt the shit out of my lambda wire? Is this possibly the reason for the leanness? Because I was led to believe that when the lambda is broken the engine runs rich as a safety feature? Or is that a load of b****x?

[ChrisLeeBoost]

What way can I test the map sensor?

[richardc9052]

It's not bollox but if the wire is frayed instead of broken then it may just be getting a weak signal, telling the ECU it's running lean no matter what it does. May not actually be running lean.

[daniel_g]

Ive had a starlet run lean till the point of melted piston, never got EML code 25.

I reckon youre not actually running lean, and its just a wiring fault.

Could get a wideband for peace of mind.

[ChrisLeeBoost]

So it's possible it could be the damaged lambda cable? But if it's just a fault then it's more than likely not the cause of the chugging? Is there any chance that a dizzy that's not timed right could cause it to chug and splutter?

[richardc9052]

Fix the wiring, reset ECU and then recheck codes. Move on from there then

[ChrisLeeBoost]

Reset ecu by pulling efi fuse?

[satyrs]

yeah that's the way to reset. and to test the map sensor its real easy. turn on ignition and measure voltage of sensor at stationairy. should be around 1.4 volts (thats normal for most vehicles) and let some one Wot it should go to 4.5/4.8 volts.

[ChrisLeeBoost]

Fixed the lambda sensor up and no joy with the spluttering, checked all my vaccums around inlet and no joy, checked map sensor all looks good will check the fuel lines and filter soon my heart is broke with this car

[satyrs]

if that is not the problem you could try and upload a video while at idle and while driving so let some tech guys from here take a look and listnen.

good luck!

[ChrisLeeBoost]

Lads what is the white screw thing off the black plug on the coil ? Is it for adjusting something?

It's such a faint sort of chugging that you wouldn't be able to see it in a video

[ChrisLeeBoost]

Just noticed that when you get to about 4.5k rpm or so and you boost a bit it starts to pop and backfire a bit ? Is that the dizzy then?

[richardc9052]

Could be or knock sensor

[ChrisLeeBoost]

Only just realised that this problem only arose after I changed my plugs?

[daniel_g]

I had a similar issue today, missfires, engine light flashing, wouldnt rev etc. and it turned out to be the earth on the inlet

[ChrisLeeBoost]

My engine light isn't coming on at all and it drives fine just when you try to boost or anything up in the rpm it chugs and stutters and if you give it to 4500 rpm or so it pops and backfires? Strange I'm goin to try change plugs back to other ones and see if it sorts it, is 0.9 the usual gap on a plug for these engines?

[satyrs]

on boost u need "extra fuel" and some more retardation (dunno if it is good english) of ignition. if this is not provided it could missfire.

special when you say that this problem came after plug replacement, check brand/gap of old plug and new. replace the old ones and see if problem is solved.

something that could happen to al techs is not putting the cap good on plug. thus no sparksz

goodluck

[ChrisLeeBoost]

Just changed to another set of plugs and the chugging has gone seemingly ! Hopefully it stays gone

[patman]

I thought you gap was 0.8mm would 0.1mm really make a difference?