Rovergauge help please

[MGB3405]

Clever Trevor no longer stock despite being on site, i used David Gerald not OEM though......

[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...

[EGB]

Have used Servisol cleaner on mine also on ECU plug/socket. After 12 years in damp UK climate they could do with a clean up.

[blitzracing]

A900ss said:

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...

This issue is the hot wire can get muck on it, so disturb its temperature / resistance response. Some modern AFMs run a little "cook" cycle to heat the wire enough to burn anything off it, but not on the Lucas set up. You have to appreciate just how tiny the hot wire is, and spurting a bit of cleaner on it is unlikely to do much.

[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.

[EGB]

blitzracing said:

Testing is performed in the following manner. Peel back the rubber boot on the airflow meter connector and leave it plugged in to the airflow meter. Set up the digital multimeter to read voltage. Insert the negative probe into the Red/Black wire (sensor ground), and the positive into the Blue/Green wire (Airflow signal).

Mark. This is a pic of my AFM from the nearside. No green or black. Where do I stick my + & - probes to measure sensor and airflow? Thanks.

[Colin RedGriff]

EGB said:

blitzracing said:

Testing is performed in the following manner. Peel back the rubber boot on the airflow meter connector and leave it plugged in to the airflow meter. Set up the digital multimeter to read voltage. Insert the negative probe into the Red/Black wire (sensor ground), and the positive into the Blue/Green wire (Airflow signal).

Mark. This is a pic of my AFM from the nearside. No green or black. Where do I stick my + & - probes to measure sensor and airflow? Thanks.

I think the red/black is red with a black tracer and blue/green is blue with a green tracer.

[EGB]

Colin RedGriff said:

EGB said:

blitzracing said:

Testing is performed in the following manner. Peel back the rubber boot on the airflow meter connector and leave it plugged in to the airflow meter. Set up the digital multimeter to read voltage. Insert the negative probe into the Red/Black wire (sensor ground), and the positive into the Blue/Green wire (Airflow signal).

Mark. This is a pic of my AFM from the nearside. No green or black. Where do I stick my + & - probes to measure sensor and airflow? Thanks.

I think the red/black is red with a black tracer and blue/green is blue with a green tracer.

Thanks Colin. Yes after a very close second look with a LED torch. The two terminals from the left hand side. Will test according to Blitz this morning. Now, after a coffee and a morning prayer!

Unable to make test, since multimeter probes can not be made to contact in AFM terminal block. More prayers needed!

Edited by EGB on Sunday 3rd August 18:19

[EGB]

My AFM looks about ok on idle at 40%. Perhaps a touch high by 5% instead of 35%. Lamdas also look ok. Again no fault codes. Good 14mm sparks on all ig leads. Wondering if it's a slightly touchy Coil and or Ig Amp. RG doesent measure these, pity!

Checked volts to the fuel pump. 2.7 volts, strange. Should it be near 12 volts? Could it be fuel pump with a low fuel pressure because of low volts. It primes ok on start up.

[EGB]

Long term Lamda.

[davep]

EGB said:

Long term Lamda.

I agree, most parameters do look slightly high. I'd hazard a guess and say that your car has had a 'tuner' chip installed and has probably been mapped.

As for the voltage drop on the fuel pump feed I'd do some continuity checks on that ASAP.

[blitzracing]

Cant think the pump would even spin at less than 3 volts...

[EGB]

blitzracing said:

Cant think the pump would even spin at less than 3 volts...

Agree. I'm surprised. Will re-measure again tomorrow and then use an extra earth (black wire)to chassis. Fuel pump primes ok and engine starts ok. The blue socket for the fuel relay is getting the 12 volts. It may be a partial break somewhere from the relay which clicks on test, to the pump.

[EGB]

blitzracing said:

Cant think the pump would even spin at less than 3 volts...

Rechecked with better ammeter clip connections to pump. On priming I get 9.7 volts. With engine running 11.4 volts. Battery voltage 12.6. No worries.

[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.

[EGB]

A900ss said:

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.

Pleased for you. Keep us updated on the Chinese AFM. Where did you get it from? Glad the RoverGauge helped pin point the problem.

[A900ss]

I fitted this:

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