Emeralds + MAP Sensor hose

[M Collins]

Hello All,

I am swapping my ECU. My Emerald ECU has no Manifold Air Pressure hose inlet, so, the idiot question is :

1) How does it know the MAP?

2) Should I blank the hose with something?

Sorry if this is a bit lame for you tech guys

Best regards,

Mark

[robin]

The emerald doesn't (usually) use a MAP sensor - it is mapped using throttle position and engine speed. It applies a trim for ambient air temperature (same as the normal ECU). It does have the ability to use a MAP sensor, but I have yet to fathom whether it can use it as the primary load indicator or whether it just uses it to trim fuelling for atmospheric pressure (i.e. the MAP is actually on the atmospheric side rather than the engine side of the throttle body).

If you want to bother with a MAP sensor (and most people don't!) you can use the VVC type sensor which is a combined MAP and temperature sensor - a so called TMAP.

Hope this helps,

Robin

[M Collins]

Brilliant!

Thanks for the replies!

Mark

[M Collins]

Ok, all in and following the first test run I am happy.
I am fiddling with the overrun settings (it does not unload very fast at teh minute) and should be mobile soon.
Thanks for your help.

And if anyone with a PTP170 is considering doing this, I'd definitely say that the speel about it being "plug-in and driveable" is balls (the throttle pot and IAC are guaranteed to be wrong). The ECU is not a standard lotus unit, it is some weird thing with an adaptor spliced into the power... Fortunately beneath all that resides the standard lotus loom. So not only do you end up cutting through/unsoldering splices but also have to fiddle with a laptop until you can get it to stop hunting under idle...

An educational couple of hours

Best regards,

Mark

[mac]

Hi Mark,


You want to tell us all a little bit more about yourself, where you are from and what your driving?



Cheers


Mac

[M Collins]

Hello,

I am currently in Cambridge (borrowing a friends computer), but I now live and work in Edinburgh. The car I drive is a dark silver R reg (mk 1). If you see me on the road, say hi!



Mark

ps. I have an electronic copy of the lotus workshop manual (pdf) that I can let people have a look at if anyone wants.

[robin]

An educational couple of hours

Best regards,

Mark

I assume you have an S1 PTP 170 and are fitting an Emerald in an attempt to make it idle better and run on very low throttle positions without kangaroo-ing?

For the S1, the PTP170 ECU has a metal adapter box that converts the K-series MEMS loom into what the Ole Buhl (sp?) unit requires. You should be able to just unplug and remove these two components and end up with the original 36-pin connector.

There is just one splice to the +12v to provide a permanent live to the ECU which for some reason isn't present on the MEMS connector.

The throttle pot needs configuring for every car - the tolerances on the pot are too wide for a single standard setting to be used for all cars.

The IACV setting is also vehicle specific - each car requires a different position to achieve the perfect idle; again it's down to tolerances but also engine wear, etc.

All ECUs need to learn these two things (including the original MEMS!).

The overrun issue is probably because you don't have the fuel cutoff set in the map, or possibly you do, but with the wrong parameters. It should cut fuel on near-zero throttle above 2,500rpm or so.

Cheers,
Robin

[M Collins]

I assume you have an S1 PTP 170 and are fitting an Emerald in an attempt to make it idle better and run on very low throttle positions without kangaroo-ing?

The overrun issue is probably because you don't have the fuel cutoff set in the map, or possibly you do, but with the wrong parameters. It should cut fuel on near-zero throttle above 2,500rpm or so.

Yes, it is an S1.
I have changed the throttle pot setting that causes it to cut the fuel, it should now cut off the fuel if the engine is running over 2500 rpm and the throttle is lifted. It still feels very light though, and I am not used to the change down requiring so little "blip".

Robin, from your description, I assume you have either used one or own one, so did you find engine braking was very much lighter with the Emerald, or have I missed something somewhere?

Overall the Emerald has been an interesting project. The car is smoother, quieter, and probably faster (feels sharper) fuel economy seems unchanged. Whilst tinkering my brother discovered the clutch actuator was missing a split pin, and the manifold was chewing one of the coolant return pipes! These things just "happen", but dont compare to discovering that the air intake was no longer anchored, and was free in the engine bay!
The PTP head was fitted by sinclairs, I assume it was them who cut the old intake off, and so I assume it was also them who cut the replacement ducting 2 inches to short and failed to secure it to anything

The last thing we noticed in this flurry of tender loving care, was that she was practically out of oil - last serviced 7K miles ago. Does anyone else find that they are drinking quite a bit of oil?

Cheers,

Mark

[GregR]

Oil consumption has been experienced on here before, and led to a replacement engine - search for 'shugmobile conversion thread'. I think he was using 1l per trackday though

[Shug]

Oil consumption has been experienced on here before, and led to a replacement engine - search for 'shugmobile conversion thread'. I think he was using 1l per trackday though

To be fair, that engine was extensively 'loved' by me for 2 years running a good 180bhp before it started that nonsense

170bhp is, however, getting to be the limit of what's regarded sensible for a stock K series bottom end...

[robin]

Yes, it is an S1.
I have changed the throttle pot setting that causes it to cut the fuel, it should now cut off the fuel if the engine is running over 2500 rpm and the throttle is lifted. It still feels very light though, and I am not used to the change down requiring so little "blip".

Robin, from your description, I assume you have either used one or own one, so did you find engine braking was very much lighter with the Emerald, or have I missed something somewhere?

Had an S1 PTP165 but with their ECU, not the emerald. Now have an emerald on an S2, though not running yet

I don't think the ECU will influence engine braking at all - if you notice it now being different from what it was with the PTP ECU fitted, then you haven't got the overrun settings right (or you have a manifold leak - did you plug all the holes left by redundant sensors?).

/nit/ there is a small possibility that a little bit more air will get pulled through the IACV if you haven't told the ECU to adjust it dynamically - but this is peanuts and I would be amazed if it made any difference to engine braking /nit/

You can tell if the overrun is working properly. Accelerate hard in 3rd to 5,000 rpm on a nice straight bit of road, preferably a quiet one, and if you can engineer to end up going down hill, all the better. Lift right off the gas and watch the tacho as the engine slows and hence revs drop - just around the 2,500 (or whatever you've set) mark you should hear the burble as the fuelling comes back in and the sparks kick off a wee pop of the unburned fuel in the exhaust.

The PTP head was fitted by sinclairs, I assume it was them who cut the old intake off, and so I assume it was also them who cut the replacement ducting 2 inches to short and failed to secure it to anything

DIY, it's the only way to know what's been done and what's been bodged; and then you also have no-one but yourself to blame afterwards either

TBH, it could also be whoever changed the fuel filter last - these are notoriously hard to remove and are attached to the backside of the plate that the ITG airbox usually fitted with PTP kit mounts on to.

The last thing we noticed in this flurry of tender loving care, was that she was practically out of oil - last serviced 7K miles ago. Does anyone else find that they are drinking quite a bit of oil?

Engines fitted with PTP kit (and properly "loved") go through pistons and rings much quicker than standard cars. You've probably lost some compression and are burning a bit of oil (and this may fit in with the engine braking being light too, but only if it was always really like that).

Best solution to this problem (without regard to cost) is to purchase a new bottom end from our pals at PTP - ITRO 1200 quid, but will last another 50-100K+ depending on how you drive it.

A cheaper solution is to buy a low mileage 2nd hand bottom end, preferably out of something like an MGF that's had a low mileage front end write off. But then you don't know how well cared for that engine ever was (e.g. does it have saggy liners that will give you HGF repeatedly). An EU3-based car is a better bet (both in terms of age and in terms of the changes made to tolerances on things like liners) than an EU2 - EU3 will have plug top ignition and no distributor, so easy to recognise.

An apparently cheap, but usually costly, route is to strip and rebuild the engine. The only advantage this has over a factory built bottom end is you can fit forged pistons which will survive PTP170 and beyond levels of abuse for much longer than standard pistons.

Hope this helps - the PTP kit is great and you will enjoy it - is it destined for the track?

Cheers,
Robin

[Lawrence]

did you find engine braking was very much lighter with the Emerald, or have I missed something somewhere?

If you take out the advance settings at zero throttle above 3k and replace them with 5 degrees or so, then that may help provide more engine braking by killing the engine's power quicker.

[M Collins]

Thanks for the advice, the engine braking definitely vanished when the ecu was swapped. I am certain that the MAP hose is plugged and is air tight. I'll tweak the advance a little over the weekend and see what happens.

I'd love to take her to the track at some point, but I am a) scared and b) very busy. I'll try to get some tuition time this spring and then by summer hopefully work will have lifted a little.

The long term plan for the car is to obtain a new(ish) k-series and give it to turbo-technics to play with. That will require a more time and money though, so it will probably be in a year or two.

Cheers,

Mark

[M Collins]

I think Turbo Technics have stopped supercharging the k-series.

So who is ?