Wedge 350i running lean ..

[mrzigazaga]

Hi Peeps.

Took Poppy for her MOT this morning which she passed with flying colours...The bloody headlamp pods and lights all worked as they supposed to?????..However that was short lived as when i got back home abnormal service was resumed...

Now all was good but the tester said she is running a tad lean so my question is....

Is it a simple matter of adjusting the AFM screw?...Is it clockwise for rich or lean?..

Its not something i would normally play around with...


Cheers


Ziga

[Wedg1e]

The AFM screw only adjusts idle CO, it won't alter basic fuelling. It's more likely that someone's been fiddling with the flap spring tension...

[mrzigazaga]

Wedg1e said:

The AFM screw only adjusts idle CO, it won't alter basic fuelling. It's more likely that someone's been fiddling with the flap spring tension...

Thanks Ian.

There is no evidence of tampering around the lid...But that doesn't mean much...

When i had the car Dyno'ed a couple of years ago it was slightly over-fuelling but the fuel pressure was lowered and that cured that...I guess i would need to have two things to achieve or check the CO...

1. A CO tester
2. A CO tester taped to the car...

Cheers


Ziga

[Number 7]

I got a Gunson one bought years ago - used once IIRC. You're welcome to borrow it.

[mrzigazaga]

Thanks Paul.


Im sure its not too much of an issue as the MOT tester knows his stuff...If it was that bad he would advise me to sort it el pronto.

I have no pinking/Detonation and will check the plugs..I would ideally need a rolling road or I'm sure i can tape the lambda in the exhaust and drive it with the tester in the car...

Cheers


Ziga

[The Hatter]

The MOT only checks mixture at idle, if it's lean at idle it doesn't mean it's lean elsewhere. If it's running OK then I wouldn't touch it.

But if you really must fiddle; the screw on the air flow meter is an air meter by-pass screw, if you unscrew it you'll get more air (leaner) and if you screw it in you'll get less (richer). If you do choose to twiddle it then make sure you know where you started so that you can get back to the original setting. I suspect you'll find it makes very little difference; and I would guess if it wasn't lean last year then what you're actually seeing is an air leak into the plenum somehow, and nothing to do with the AFM.

Edited by The Hatter on Friday 7th October 18:59

[mk1fan]

Tut. Coming on hear with sensible advice. I don't know

[mrzigazaga]

Thanks Martin.


I will probably leave it alone as its pulling like a train.

I could check for an air leak..The car is really hard to start in the mornings irrelevant of outside temperatures.

It never used to be...

Cheers

Ziga

[Number 7]

mrzigazaga said:

The car is really hard to start in the mornings irrelevant of outside temperatures.

It never used to be...

Cheers

Ziga

Back Street Car Salesman said:

I told you not to disconnect that cold start injector

[ElvisWedgely]

Number 7 said:

mrzigazaga said:

The car is really hard to start in the mornings irrelevant of outside temperatures.

It never used to be...

Cheers

Ziga

Back Street Car Salesman said:

I told you not to disconnect that cold start injector

Tony. TCB.

[The Hatter]

I haven't laughed so much in ages Stuart!

Thread meandering... The cold start injector has a purpose, as does the plenum heater. However cars are designed to start in seriously cold arctic conditions and these devices contribute to that. I suspect the effects in the UK climate are not very significant; there's plenty of info on the internet that will tell you all about it.

[jon haines]

Stop worrying and fannying around Zig get it out and give it a good thrashing and all will be resolved.

[jon haines]

Stop worrying and fannying around Zig get it out and give it a good thrashing and all will be resolved.

[Wedg1e]

The Hatter said:

I haven't laughed so much in ages Stuart!

Thread meandering... The cold start injector has a purpose, as does the plenum heater. However cars are designed to start in seriously cold arctic conditions and these devices contribute to that. I suspect the effects in the UK climate are not very significant; there's plenty of info on the internet that will tell you all about it.

Absolutely; when Lucas first developed it they had in mind fantastic British executive saloons that would be sold in huge numbers all over the world... particularly California where the emissions laws led (or hindered) the world. Said cars would convey captains of industry to high-flying business meetings in all weathers, to say nothing of the wife to her Bridge club and the kids to ice skating tournaments in St. Moritz.

In the real world... my car has both throttle heater and cold start removed, bypassed, blanked off and never fails to start in any weather I've chosen to expose it to. If it's -20C and 6" deep in snow I'm probably not going out in the TVR and I'll trade that minor inconvenience for the ability to remove the left-hand rocker cover without stripping half the injection system first. Why? fk knows, but at least I can if I want to

There should be no need to disconnect the CSI: the theory goes that if it sticks open or the thermotime switch is somehow faulty then you get tons of fuel going in. In practice, because the CSI gets 'exercised' every time you crank the engine it should have no reason to stick open; it's getting flushed with the same fuel the rest of the injectors are seeing, after all. On the other hand if it sticks shut then it's no worse a situation than trying to start with it disconnected.

Wedges that don't start easily usually have other issues than the absence of the trivial extra bit of fuel provided by the CSI.
If it won't start first crank (say 5 seconds), by now the fuel rail should be up to pressure, so ignition on, kick the throttle a few times which triggers the 'acceleration pump' feature of the injection (like the good old days of carbs, remember? ). So now you have your extra fuel sloshing around in the inlet tracts. Crank again: if it still won't fire it's not from lack of fuel (dead fuel pump aside).

[Wedg1e]

The Hatter said:

The MOT only checks mixture at idle, if it's lean at idle it doesn't mean it's lean elsewhere. If it's running OK then I wouldn't touch it.

IIRC given the age of the (non-catalysed) RV8 the MOT allows up to 3.5% CO; on that basis I don't know how the MOT man decided it was lean!

[mrzigazaga]

Wedg1e said:

Wedges that don't start easily usually have other issues than the absence of the trivial extra bit of fuel provided by the CSI.
If it won't start first crank (say 5 seconds), by now the fuel rail should be up to pressure, so ignition on, kick the throttle a few times which triggers the 'acceleration pump' feature of the injection (like the good old days of carbs, remember? ). So now you have your extra fuel sloshing around in the inlet tracts. Crank again: if it still won't fire it's not from lack of fuel (dead fuel pump aside).

Hi Ian.

When my CTS was playing up...(The crossed wires) the car used to start within 5 seconds..My CSI is plugged in...The fuel rail gets up to pressure on the first couple of cranks...Its a bit chuggy when it starts but soon smooths out...One thing i have always noticed is that the rpm is never higher than 950rpm which is what it is when its warmed up...Maybe i have an air leak which would account for the thinning out of the extra fuel for cold start?...Could that be a symptom of a failed EAV?...I have a brand new one if it is...

[Wedg1e]

mrzigazaga said:

Hi Ian.

When my CTS was playing up...(The crossed wires) the car used to start within 5 seconds..My CSI is plugged in...The fuel rail gets up to pressure on the first couple of cranks...Its a bit chuggy when it starts but soon smooths out...One thing i have always noticed is that the rpm is never higher than 950rpm which is what it is when its warmed up...Maybe i have an air leak which would account for the thinning out of the extra fuel for cold start?...Could that be a symptom of a failed EAV?...I have a brand new one if it is...

My car fires up OK , runs for a minute or so then starts hunting but once it's warmed up a bit ot smooths out. It's done it as long as I've owned it. Idle speed is about 750-800, it will go down as low as 600 (all lights & fans on etc.) but still runs OK. It also doesn't fast idle and then slow down; that seems to be common with the RCV8 whereas the Ford V6 had a very prominent fast idle (was a bit of bugger on the old Granada hearses as they would 'creep' rather badly, not want you want when the Director is walking three feet in front of the bumper!).
If you had an air leak then yes it'd be lean and yes it could affect starting but it'd also tend to be evident through the range... unless it was over-fuelling in which case the extra air would be welcome.
The EAV starts off open and closes as it warms up so if it was stuck shut it could make starting harder as you'd have cold-start fuel but no air to go with it; you'd tend to notice it in the exhaust though. If it was stuck open then it wouldn't make any difference to starting but would once the coolant temperature warmed up.

[mrzigazaga]

Thanks Ian.

I might just give the ole throttle a kick then...

[mrzigazaga]

Well I tried the throttle kick...Checked the overrun valve..Checked the coil for spark..Checked the hoses for splits..Checked the crankcase breather...Injector connectors...Timing is okay.

Cranked it over a few times and removed plug No.2 but it was dry... And does look a bit lean...However there was a strong smell of fuel coming out the exhaust
BPR6IEX

Compared to a B7ECS that was in there for two months and fouled up a fair bit but I think was mainly due to the CTS not working.
B7ECS

The pink is the injector cleaner.


Im now thinking that it could be the 2nd earthing point on the LH rocker cover...There are two there and I haven't managed to get to the lower on...Now this is for the CTS and is connected to 5..13..15..16..17 pins of the ECU which I'm not sure all do, However if these are for the injector bank then I may have an easy fix on my hands...If not then I'm totally stumped....

Here is a video of the cold start...I have cranked it prior to the video so around 10 rotation previously....

https://www.youtube.com/watch?v=8MsV7BH_INU

Any thoughts??


Cheers


Ziga

[Wedg1e]

PM sent.

ETA it's usual for all the injection earths to be on the same stud on the cylinder head.