82 replies to this topic

[genpop]

"As I understand it this is way to many steps for a cold engine?"

No, cold engine is max steps

Warm engine is about 30 steps.

30 steps at idle , that it can decelerate when needed.If condition of engine changes.

You may reset ecu but then you need some 30 to 50 km until ecu has learned again.

When you switch to ALLData you can see all values. For example pressing the accelerator.rpm, and so on.Give us a new logfile with mems scan.

 

Other idea!

Is this lever free moveable and is it at middle position when engine is warm?

Attached Files

•  lever.JPG   58.85K   0 downloads

Edited by genpop, 30 January 2020 - 04:35 PM.

[Robbie693]

The lever is free yes, it was a bit sticky at the start of all this but I cleaned it up and lubricated it with some light oil and it's now ok.

 

I am pretty sure the lost motion link is in the middle when warm, certainly is when cold as I just checked. Will look again tomorrow.

 

Do you mean do another logfile after I reset ECU?

[genpop]

Yes.,every time you hook up mems scan. It is free

[Robbie693]

 

I am a bit concerned about the battery dropping to 11.7V. I will monitor it but I can't imagine just the battery would call all these problems, I've had many a flat battery in the past with nothing like this happening...

[genpop]

You should compare volts at battery with volts from ecu,(At the same time) if they differ you have an earth problem.

[Robbie693]

No luck I'm afraid.

 

Did a log before the reset, just incase I needed to retrieve some settings, checked battery volts  right after start up - 13.7 at battery vs 13.5 recorded by ECU.

 

 MScan before reset.txt   277.19K   1 downloads

 

 warm after first log before reset .jpg   71.98K   8 downloads

 

Switched off, sharp intake of breath and pressed the ECU Reset button. Started it and did another log

 

 MScan after reset.txt   76.44K   1 downloads

 

 after reset.jpg   74.31K   9 downloads

 

 running after reset .jpg   80.27K   2 downloads

 

Took it for a 35 mile drive, still performing the same. On return Battery voltage was 14.0, ECU voltage 13.9. Did a third log, revs even higher.

 

 MScan after run.txt   218.08K   1 downloads

 

 After run.jpg   70.92K   3 downloads

 

 after run2.jpg   77.06K   0 downloads

 

Lost motion gap when hot was  slightly off centre up when running, slightly off centre down when off but there was still play before it contacted the lever

 

Running - 

 

 hot engine running.JPG   39.56K   0 downloads

 

 

Off-

 

 hot engine off.JPG   55.93K   0 downloads

 

What next please? 

[genpop]

It is getting to become a problem

You still have IAC at 0

First switch to actuators and set IAC to 25%, then

switch to adjustments in mems scan . Then set FuelTrim  leaner. Stft is at 103 to 105 at the moment, set it to 98.When you look to the logfile LTFT is at 128 at the moment it should fall to 125 then.

Have it running a few moments then set idle speed to 850.

If yoü doubt about this or it does not work for you you may reset everything again, then you should set IAC, with running engine watching IAC on ALL DATA, on the screw what should not be touched.

by the way Could you have a look to the logfiles with mems rosco?

[Robbie693]

Unfortunately I can't get the mems rosco charts to work, possibly as the laptop I am using for the diagnostics is ancient and running Win XP.

 

So today I went and tried the adjustments. Firstly I warmed the car up, switched off and advanced the IAC 25%, this gave me 44 steps.

 

Then I started up and tried to adjust the STFT, at first I leaned it off but that caused the STFT to rise so I went the other way and got to 8 points richer to bring it down to 98. It was fluctuating between 97-100.

 

This caused the LTFT to go up rather than down - rising to 136 so I decided to reset my adjustments as the pc was about to die. Why did it go up?

 

I've done a log while I was doing the adjustments, at the end I was knocking the trim back to 0 before switching off and pressing the 'Reset Adjustments' but I am not sure this does anything as the readme file says the facility to restore factory settings is not implemented yet.

 

The battery voltage was only 12v this morning even after a 30 mile drive yesterday so I think it's on the way out. Could the battery cause all these problems?

 

 adjustments.txt   267.35K   5 downloads

 

 

[Quinlan minor]

It's certainly not going to help.

I'd recommend fitting a new battery, first.

[genpop]

I still think it is a mechanical problem.Open the iac and check for rust.

Every time you step on the accelerator your idle rpm differs to the former value.

If you have a desktop with a newer system you could install mems-rosco there.As well i can open mems-scan logs with memsanalyser from rmrsoft.com

If you have excel on your pc and you are familiar with excel you can import txt files, select some columns and show them as graphs.

Edited by genpop, 03 February 2020 - 04:27 PM.

[Robbie693]

All the modern computers we have now are macs but interesting what you say about excel - I'll try see if the mac version will read the txt files, thanks.

 

New battery on order for what it's worth - I'll see how that goes before delving in to the IACV

[Robbie693]

New battery made no difference so I stripped the IACV down. Didn't seem particularly dirty or corroded and seemed to move ok but I cleaned it up with a bit of WD40 and it became very free moving, put a smear of grease on it and it became a bit less loose but it's actually the rubber boot that damps its movement the most. Never enough to not be overcome by the spring in the throttle linkage though. I also cleaned up and greased the cable pivot. Also re-tested the motor resistances before and after I put it back together. 

 

Starting it up it seemed to idle too low if anything for a cold engine - about a 1000rpm and the revs were hunting up and down - I could see the stepper moving in and out pushing the revs. After it warmed up it was back to as it was before. I did another log (attached) and noticed that when I gave it a good rev the 'Unusually low lambda signal' anomaly was recorded so I cleared this.

 

Whilst it was apart I did another test on the TPS and I couldn't get it to read a resistance beyond about two thirds throttle, wether this was because I was having trouble 

holding two probes on to the pins with one hand while moving the throttle with the other I am not sure but wouldn't a problem with the TPS show up as an error in Mems scan?

 

 after iacv rebuild.txt   219.33K   4 downloads

 

 

[genpop]

it is becoming very strange but when you have a look to the graph, you see the carbon canister valve working all the time. So check this. Squeze the hose to the canister valve, what happens?Disconnect the wiring to the valve, what happens?Why is it working all the time? Normally it opens only some times and when water temperature is >75 degrees.

As well there is an other idea.Somebody reported that the gasket for the electrical intake manifold heater was damaged and the engine got some additional air from there.Check this with some brake cleaner sprayed to the bottom of the manifold.What caused the spikes?Stepping on the accelerator?

Attached Files

•  air system.JPG   56.95K   7 downloads
•  afterIAC.JPG   49.93K   7 downloads

Edited by genpop, 06 February 2020 - 12:30 PM.

[Dutchdave's25]

by looking at the picture you took of the lever, I wonder if your intake valve can fully close.

the adjusting screw seems to be very far out, so far out that its always touching the plunger thats connected to your stepper motor.

 

I would suggest you;

1. disconnect your throttle cable

2. set the screw way back (like in my picture)

3. start your engine and see how you go

 

I have taken a couple of injection units apart and i've never a screw as far out as yours... ( what does happen is that the valve gets sticky, i havent found a solution to fix this..)

here's an example of 1:

 

if you need spares, I still have some lying around..

 

good luck!

[Robbie693]

Thanks both,

 

I have been reluctant to mess with the stop screw up until now as I know it has never been touched in the cars life and I worry that adjusting it would be just covering up another problem so I have left it until a last resort.

 

The purge valve is an interesting idea, the log started when the engine was already warm but if it is only supposed to open periodically then something could be wrong, I'll do the tests suggested.

 

I did rev the engine a few times during the log so I suppose that's what the spikes are