Mgf donor car: building an MG Allegro VVC!

[edk83]

Hi Dave, do you know if it can be checked on pscan? If so I'll buy one before stripping the vvc down.

The head was replaced in 2009 by MGOC in Cambridge, while it could have been done wrong it wasn't done by a random garage.

[bod1066]

Hi I don't know, I have got a T4 Testbook, and at idle I think its should read 235, but as I said have done 4 or 5 that were from other garages that were out, it shows you how to set them up in the workshop manual, Dave.

[edk83]

Shame your not in the Midlands, could just do with getting a testbook on it!

[Rob Bell]

Pscan reads VVC advance angles

[edk83]

Awesome, I'm pretty much sold on one, just emailed them in fact.

Hoping they are fixing the issue with live data from the mem2 mgf though

I'm assuming its the cam sensor that feeds the vvc angle data to the ecu?

[edk83]

Just looked at my ecu and the number on it ends in 1 so hopefully it will be fine with pscan

[edk83]

Just been on pscan, here are my results - cam period was at 216 degrees, this was with the engine pretty much cold at idle, didn't seem to change much when I revved it.

Looks like I have a duff map sensor and maybe a fuel temp sensor if it has one.

[bod1066]

HI, if the 2 cambelts are spot on and the reading is 216 degrees when warm, and not 235 degrees at idle, then the vvc have not been set up correctly.

[edk83]

Hi

It seemed to stay at 216 degrees but I didnt run it for more than 5min. I read that the ecu will push it to the minimum when its in grouped fueling mode which im.hoping is the case with the map sensor not giving an output.

Would be a shame if the vvc wasnt put back in right as it has a full history and MGOC did the work.

Bought a replament map sesnor, will have to wait for that, might try my other cam sensor and see what the period reads.

[talkingcars]

Did you run it long enough to switched into closed loop?

[edk83]

How long is that?

[pscan.eu]

Is it anything to do with "Closed loop fuelling status" which is one of the parameters that you can read with your pscan?

[talkingcars]

On a warm up cycle the ECU will run "open loop" which is like having the choke out, once warm the ECU switches to "closed loop" fueling which is more controlled, it will switch to "open" on hard acceleration or over run.

If the ECU isn't switching it could indicate that the ECU isn't seeing an input such as coolant temp. As Philip says it shows in the pscan readings.

[edk83]

Interesting, will have to play with it more.

I did see the coolant temp at 11c before I started the engine, so should be about right.

It shows no value for the manifold pressure at all and its logged as a fault so thats my first fix.

The ambeiant air temp reading was there and working too.

It had just about lowered the idle rpm to 900 when I had to go back in so isnt that the same as the choke being back in?

A memeber of the mini forum says thier vvc will rev to 7k from cold!

The cam period on mine is reading 216 degrees, hoping this is due to the ecu forcing the min value due to error state and not a jammed mech, have been told min should be 225.

[talkingcars]

I don't think mk1 VVC with MEMS 2.0 have a manifold pressure sensor, they definatly don't have a pressure sensor in the ECU unlike later MEMS 3 cars.

Closed loop fueling doesn't mean that the engine will run faster, it adjusts the fueling etc to run richer.

[pscan.eu]

They appear to on the Lotus
see http://www.sandsmuseum.com/cars/elise/i ... 2_of_3.pdf
it's the same ECU as far as I know

[edk83]

Yeah they do have them, on the end of the intake. Mine is looking old although it is plugged in!

[talkingcars]

I stand corrected, that guide is useful and duly book marked.

[pscan.eu]

I asked another of my customers to check his numbers on a cold idle with pscan. This is what he sent me:-

Engine Speed 1172 rpm
Coolant Temperature 38deg C
Camshaft signal okay
Cam input history Input was low
Cam position 1deg
Requested cam period 225deg
Measured cam period 226.2deg
Inlet valve open angle 717.4deg
Inlet valve closed angle 223.6deg
Closed loop idle control status Active

He said that Intake manifold pressure engine off is 100kPa and at idle (engine warm) 25 kPa

Hope that helps

[edk83]

Thanks for posting that up will be good to compare.

I need to look at my value for requested cam peroid as that should be the clue on if the vvc mech is able to give what the ecu is wanting.

New map sensor should come begining of next week.

Going to start stripping the interior and front end tomorrow. Need to get on with it and if the vvc mech does need to come out I'll do it further down the line. The mgf is holding me up working on the Allegro!