9 replies to this topic

[hulsmeier]

Hi

I'm using the MEMS ROSCO diagnostic from MEMS fcr

I'm aiming for a stepper position of 35 as recommended but my count on the software is 69-90. This is with the temp >80°C

Does this mean my stepper is duff? I checked the coils and they all measured the same resistance, and also reflowed the solder

Thanks!

Cal

[genpop]

69 to 90 is too high.At idle IAC should be around 30 or better what hot idle says. On the webside of MEMSFCR.co.uk

 you can find a description how to set IAC.

Edited by genpop, 29 July 2022 - 04:49 PM.

[hulsmeier]

Yeah I cant seem to get lower than 60. If I drop it too far from where it is now the engine begins hunting then eventually stalls. All sensors are reading okay with now faults registered

[Pops_Guild]

How are you trying to adjust the steps? There’s a very specific way to do it.

Are you sure you’re at full temperature? You say >80degrees. It needs to be greater than 88degrees to be sure. Some engines are bit less, some need a bit more.

[hulsmeier]

I couldn't get the temp to 88c. I will try again and try and get it to that temp.

[Pops_Guild]

See how you go. Once you get it to near 80, if then hold the rpm at 2500 for 3-4mins that should bring up the temp substantially. Wait a couple of mins to see where it settles and if not 88+ try again.

If the temperature does not rise by doing this, then you likely have an issue with a blocked or semi-blocked inlet manifold. Might get solved by a high pressure flush through.

You need to get the temperature at 88.

You haven’t answered how you were trying to adjust the steps? That too is important.

[hulsmeier]

Hi
Thanks for the advice.

I read a bit about possibly the temp sensor in the throttle body not getting the flow so I'll give that a flush next. I'm also wondering if the thermostat could be at fault too so I'll replace that for the sake of it.
As for the process I'm following the guide in the memsfcr, however given that I can't get the stepper at 35 I have been going off the idle speed and getting close to 850rpm. When I've been adjusting it so the screw is further retracted to get a lower stepper count the engine starts to hunt and fall below 850rpm so I move it until I get a stable engine speed but I am guessing the problem is I haven't reached 88c. when adjusting the screw I was leaving around 1min for it to settle, but again the value on the stepper count was still high that any adjustment wasn't making much of a difference

Thanks again

[Pops_Guild]

Funnily enough, the guide on MEMSfcr are mine, so if you’re following those, you’re doing it the the right way 🙂 (the ClassicMiniNLA FB page is mine, and where I put the post originally)

You absolutely need to get it to the correct running temperature before you adjust the steps. Trying to adjust it when it’s not will make things more wonky unfortunately.

I assume the app is telling you there are no other faults and your MAP sensor has a value of around 35?

If you have other faults, they need to be addressed too before making any stepper adjustment.

Have you set the Lost motion gap correctly too?

Edited by Pops_Guild, 30 July 2022 - 12:39 PM.

[hulsmeier]

Ah great! Thank you for sorting the guide out it's a great source of information. And being able to monitor these things on spi easily is a great tool to have.

I have ordered a new thermostat and temp sensor Incase they're the issue and will give the throttle body a good clean through too

I'll check the map value again I can't recall what it was now, the fault indicator was flickering on off I wasn't sure if this could be indicating an issue as it wasn't permanently red.

I have set the lost motion gap too.

Thanks again and appreciate your help

[hulsmeier]

Hi just finished setting the car up. Changed the temp sensor and thermostat, the thermostat was the right one but changed anyway. Didn't think it was ever going to go to 35 but it did. Very pleased to know it's set right now
Thank you for the help!