5 replies to this topic

[brivinci]

I had a thought the other day and wanted to see if my car is ever actually getting wide open throttle. Car was fitted with a mk1 pedal and paddy hopkirk pedal and I wondered if it was causing any issue.

So, I weighted the pedal to the floor and had a look. To my surprise, the throttle was hitting the stop BUT looking down the barrel, it don’t look right. Sure enough, it wasn’t really reaching what. The cable is pulling it to its stop, but if you push on the end that depresses the stepper motor plunger (by the lost motion thing), you can push the throttle, what I would think is a decent amount more!! Posted video which better explains it.

https://youtu.be/fjb...mbSKKBUCnKdWLH7

The lost motion is set correctly. Dead in the center. What do you guys think?

Edited by brivinci, 11 March 2025 - 04:57 AM.

[Steve220]

I had a thought the other day and wanted to see if my car is ever actually getting wide open throttle. Car was fitted with a mk1 pedal and paddy hopkirk pedal and I wondered if it was causing any issue.

So, I weighted the pedal to the floor and had a look. To my surprise, the throttle was hitting the stop BUT looking down the barrel, it don’t look right. Sure enough, it wasn’t really reaching what. The cable is pulling it to its stop, but if you push on the end that depresses the stepper motor plunger (by the lost motion thing), you can push the throttle, what I would think is a decent amount more!! Posted video which better explains it.

https://youtu.be/fjb...mbSKKBUCnKdWLH7

The lost motion is set correctly. Dead in the center. What do you guys think?

 

You potentially need to set the lost motion gap:

 

https://memsfcr.co.u...ost-motion-gap/

[brivinci]

I guess my initial finders could be off as I was doing this with the ignition off. I'll power it up, check/reset the lost motion and see where I am at. 

[sonscar]

You may find that you achieve 100%MAP without getting full opening of the blades.My understanding,which could easily be wrong, is that once full MAP has been achieved then further opening does no extra.Steve..

[brivinci]

I checked out lost motion and it was spot on BUT while reading through your link (TY), I clicked on the click about the stepper motor.

Ok, so I got the car up to temp and fired up to MEMsFCR. Right away, I was shocked to see the stepper motor was around 100!!! Was very interested seeing what I could achieve and how it could change the cars drivability. I started making adjustments and it started dropping slowly. I was taking my time to let the ECU adjust and settle between adjustments. I got the numbers down to within the 50's until the RPMs suddenly picked up and when settled, the stepper jumped back to high 90's. Noticed a blinking warning fault. The Lambda was now sitting at 0V!!

Now, the car was idling for a bit but the temp never went over 88. Everything else seemed ok and there were no other faults. The MAP was running 50-60. Once the lambda stopped, the MAP moved up 60-68. 

So, not sure what the story is here. I would like to think I can trust the numbers I saw and that the lambda is faulty. Thoughts? 

[brivinci]

Tonight’s update.
I decided to rerun it. I took it up to to fully warm and did a final adjustment to the stepper. It’s now fully dialed in, right around 33-38. My 94 Monte has factory spots/fogs across the front so a little higher was the target.
After a full 20 minutes of idling, the lambda seemed to still be operating as it should. (Video link attached).
https://youtu.be/vvL...GJryDe4tbN7U_2Y

I decided take it for a ride to see how it felt. Only did 15 minutes. I assume the ECU needs time to relearn things. Car drove ok. Didn’t stall but was slow to loose revs BUT when I got home, I hooked up MEMs and it seems the lambda is working as it should. Maybe last nights issue was with the MEMs connection?
https://youtu.be/vvL...vT8steaOe5SyR-0