Rovergauge help please

[A900ss]

For various reasons I haven't driven my car for about 4 weeks and its now running like a dog.

It's popping and banging and feels like its running on 6 or 7 until it clears its throat. (Well, it was but now it can't seem to clear its throat at all!!)

I therefore hooked it up to Rovergauge to see if any fault codes and there were none. It is running at 100% long term and short term trim for both banks. It also stinks of fuel and emits white smoke (petrol?) from the exhausts. It has now got so bad I need to hold my foot on the throttle so it doesn't cut out.

Screen shot at idle:


Screen shot stationary but with some revs:


Screen shot whilst driving:


Since I took these screenshots, its got worse and I'm having to use more throttle just to stop it from stalling.

Like I said, both long term and short term trim are at 100% and I notice that the fuel range that all screenshots I'm working in are deep in the bottom orange zone.

The last time I drove it was 1,000 miles in France and it run like a dream getting 25/27MPG which is the best its ever given.

I have recently replaced all plugs, HT leads, rotor arm, ignition amp, dizzy cap, fuel regulator and vac advance on dizzy. Replaced 6 months ago was the coil.

I know most of the above are electrical and with 100% trim, I'm guessing this is a fuelling issue rather than spark issue.

AFM? It's the original AFM to the best of my knowledge but I don't want to replace items just for the sake of it (especially an AFM as they are quite expensive).

Thoughts most welcome.

Karl

PS -How much does CANEMS/Megasquirt/Emerald cost fully fitted? I'm getting fed up with this.

Edited by A900ss on Thursday 31st July 17:14

[A900ss]

I thought -100% means the ecu is pumping too much fuel in so the trim to -100% is to reduce the fuel going in but as it's At -100% (ie can't help anymore), it's running rich.

It is the standard alarm so I will try an ECU reset. I assume that you just unplug the ECU from the cables in the footwell?

[A900ss]

Ok, ECU reset just done and fired her up.

She was running beautifully at idle after this. The car didn't get warm enough for long term trim to move from 0% after the reset but the short term trim was rock solid at 0%, engine running great at idle.

Quick dab of the throttle and the car went back to being a dog again. 1500RPM to 700 RPM hunting. Short term trim all at -100% again. All from touching the throttle (which I'll need to do if I want to actually drive the thing repeat her than just idle it!!!)

A few questions about the AFM:

How can I check it's the AFM and not the connections to it?

Are they just straight swap over to a new one or do they need calibrating?

Where is a good source of good AFM's as I know Blitz doesn't rate the copies?

Thanks in advance again.

Karl.

[A900ss]

danbourassa said:

Try unplugging the MAF to see if the engine runs better. Since you don't have a fault code, the ECU is actually using the MAF data, as bad as it is. Unplugging it should set a MAF fault. The ECU will then fuel based on RPM and TPS. This is usually not as good as using the MAF signal, but, in your case, it should be an improvement.

Ok, unplugged the MAF and these are my thoughts:

Let's use my car running normal as a base of 10

Before the ECU reset this evening it was idling about a 3 out of 10 and eventually stalling itself whilst idling.

After ECU reset, back up to 10 again however after a dab of the throttle it went nuts again, so back down to 3 out of 10

AFM unplugged and the idle is now about an 8/10. Dab of throttle and still about an 8/10. Back to idle and still an 8/10. It is not as good as normal but nowhere near as bad as it was. Still feels a bit 'fluffy' in engine pick up and idle though, if that makes sense with the AFM disconnected but then again I'm not sure how it's supposed to feel with the AFM off.

My battery has died on the laptop so can't connect Rovergauge up with MAF unplugged but will RG still give me trim values with the MAF unplugged because I can check them in the morning if it does?

Thanks.

Edited by A900ss on Thursday 31st July 21:02

[A900ss]

AFM's, what's good and what's not?

£168 from Clevor Trevor but seems to be pattern part
http://www.clever-trevor.net/TVR/Parts_details/E20...

Power want £250 but looks to be genuine Lucas that has been reconditioned
http://www.powersperformance.co.uk/store/slug/air-...

Any other (better) options?

[A900ss]

This one appears to be genuine Land Rover. Has anybody used these people? The Brtipart AFM'S are about £100 so don't want to pay twice that for this one if it turns out to not be genuine just with a LR sticker on it.

http://www.lrdirect.com/ERR5198-supplied-by-BRITPA...

[A900ss]

I know that this seems a bit cheap but......

Does anybody clean their AFM on a regular basis with any positive results? Has anybody had a dodgy AFM and cured it with cleaning?

I'm thinking for £4, it's got to be worth a try.

http://www.halfords.com/motoring/engine-oils-fluid...

[A900ss]

I've cleaned the MAF and it has changed things:

Before cleaning it was at -100% short term from all the time. It now reads zero (bang in the middle) at idle but then goes out to -100% when driving.

The long term trim was at -100% all the time before cleaning. It's now at zero as well. This is even after a 25 mile drive so it should have got warm enough to set itself.

Driving was delightful for the first 10minutes. If I hadn't had Rovergauge hooked up I would not have known that is was running -100% short term trim. It felt fine. It must also be said that the MAF on Rovergauge at this point was showing 34% when idling which I think is about right.

However more and more into the drive, when the engine was giving off more and more heat, it went back to kangarooing again and not being able to idle (hunting upto 1500RPM down to 500 RPM until it stalled itself).

So it got worse when it got hot but I don't understand why no long term trim was being shown.

Thoughts most welcome but I guess I now must face up to ordering a new AFM.

[A900ss]

Just to close the thread (and thank those who helped with the diagnosis), I have fitted a new AFM and she running well again.

I have cheated a little as I am 'considering' an after market ECU this winter and didn't really want to spend £200+ for a new AFM so have fitted a new Chinese copy at £46.50. Let's hope it lasts until winter....

Thanks all.

Karl.

[A900ss]

I fitted this:

http://www.ebay.co.uk/itm/171109203097