5 replies to this topic

[tmsmini]

I replaced the injectors on my car today and connected an SP ACR4. I should have taken a before and after reading but I did not. The SP info says expect 30 KPa at idle, but I am closer to 50. I get 100 KPa with the engine off which is what is expected according to SP.

I will remove and clean it tomorrow, but I am wondering if I should swap it.

Terry

[mykweb]

sorry there seams to be a confussion here

The MAP sensor will show 100Kpa when the car is switched off. This is 1 atmosphere of pressure.

The MAP sensor detects Manifold Absolute Pressure. This value will decrease when the engine is running.

You say you swapped the injectors??? WHY?

What is your original issue to make you think / swap the injectors or MAP sensor.

Mike

[Sprocket]

Low manifold vacuum can be down to bad valve seal, incorrect cam timing or an air leak. Im sure the engine is idling a little uneven?

What were the readings for

Ignition advance
Coolant temp
Air temp
stepper position
Lambda volts (changing)

[tmsmini]

Actually it seems to be idling quite well, right around 900 as much as an MPi usually does.

ECT - 97
IAT - 55
MAP - 45
Stepper - 21
Lambda is fluctuating quickly and regularly

I don't think the ACR4 gives an advance reading. I changed the injectors as I had a spare set sent out for refurbishment a few months ago. I meant to install them within the 30 day time period suggested, but I got distracted by the wife's Traveller.

I need to convert KPa to something else for the value to be recognizable by me
1 Kilopascal = 0.145037738 PSI
1 Kilopascals = 0.2952999 Inches Mercury

So I think I should be expecting 20 inches of vacuum, but I am only getting about 14.
Certainly lots of places for leaks on an MPi manifold.

I swapped the MAP sensor for a spare anyway as the tang to hold the electrical connection was almost broken off. These values are from this morning.

[tmsmini]

It would be nice if the ACR4 had data logging. It seems to be driving nice and off throttle I see the KPa value go to 30, but return to around 45-50 at idle when stopped. But I do not know what the values are for other sensors. You can save a screen, but there is a delay and it only gives 4 data values.

[tmsmini]

The car appears to be running well, so perhaps this is a case of too much information and i should just drive the car. We had our first cold(relative term) morning mid 40's F and the car ran well.

I did find this chart:


and although it is not specific to the Mini it indicates a range of values for MAP at idle. I was really just looking for a range of valid values for MAP, more than the expect 30 KPa at ilde that Sykes-Pickavant provides. It seems that I should be looking for a leak somewhere, but it seems to be running too well. perhaps that is a disadvantage of an adaptive system adapting too well to a fault.