Low power 4200ccc

[daglocks]

Driving my son to training yesterday, the car had very low power. About the same as my wifes Hyundai i20, meaning I could get up to speed, but accelerate only slowly.
I had a coil pack fail last year after I got water on the engine cleaning it (stupidly!), and it was a similar loss of power to that, although the engine wasn't lumpy or rough.

When I got to my destination, i plugged in an OBD reader and used OBD Fusion app on my phone which showed no error codes. I reset the error code memory.

After an hour, I drove home, and the car was back to normal, with good power. What could the problem have been?

On another matter, the lamp in my clock has failed, how do I access it to change? Its annoying me!

 

[Zep]

Hmmm, that’s an odd one. I’m thinking maybe throttle potentiometer.

As for the clock, you won’t believe it, there isn’t a bulb. You need a good used clock.

 

[philw696]

Happened to me 10 years ago somewhere in the Alps.
Battery reset and went and had a good lunch.
Back on and never missed a beat for the rest of the trip.

 

[2b1ask1]

It is just being an Italian Bella, Zep & Phil have it covered.

The clock is a blown ballast chip on the photo luminescent driver, I looked into repairing these years ago and nobody had any of the chips remaining, the manufacturer would make me a 10,000 unit run of the chips no problem but I couldn’t really justify the £1,000 outlay. So I did develop an LED replacement array but it was just patchy and looked cr@p no matter how much I diffused it. So yes, just buy a working used one.

 

[mjheathcote]

Hmmm, that’s an odd one. I’m thinking maybe throttle potentiometer.

As for the clock, you won’t believe it, there isn’t a bulb. You need a good used clock.

Or a cheap tarnished one for the gutts!

 

[2b1ask1]

Link to the clock fix: Post No.27 onwards

 

[lambertius]

Link to the clock fix: Post No.27 onwards

Do you still have the details for the part numbers? A lot has changed in parts and availability since 2011!

 

[lambertius]

Hmmm, that’s an odd one. I’m thinking maybe throttle potentiometer.

As for the clock, you won’t believe it, there isn’t a bulb. You need a good used clock.

Makes sense - according to one of the service books I read, resetting the codes/battery cut off makes the car run a throttle learn on the next start up.

 

[2b1ask1]

Do you still have the details for the part numbers? A lot has changed in parts and availability since 2011!

i can have a look if I have it recorded.

 

[TimR]

Makes sense - according to one of the service books I read, resetting the codes/battery cut off makes the car run a throttle learn on the next start up.

This is true...
Its a good reason not to use the isolator switch. Everytime it is switched off and resets, you probably need to actively manage the relearn.
Conversely, it has its place. I swapped to a pod type filter, and will be changing out secondary cats - and will reset.

 

[Navcorr]

just buy a working used one.

Someone put one up for sale here a short while ago. Looked at your notes at the time, and a few other references, which indicate the faulty chip is HV825. For reference:

HV825 - Display and LED Drivers - EL Backlight Driver ICs

Inductor Based Single Lamp EL Driver

www.microchip.com

I've not tried one of their chips (my clock is fine) but they offer small quantities at decent prices. Maybe worth trying before shelling out for a 2nd hand clock.

 

[philw696]

Maf260 had one for sale if I remember.
We don't see much of him these days since he became a Bentley Boy.

 

[lambertius]

This is true...
Its a good reason not to use the isolator switch. Everytime it is switched off and resets, you probably need to actively manage the relearn.
Conversely, it has its place. I swapped to a pod type filter, and will be changing out secondary cats - and will reset.

The process is just to turn the ignition on and wait 20 seconds before starting the car. I shouldn't be affected by the filter or the cats, the process is checking the minimum (closed) and maximum (open) position and then using the self generated values to calibrate a curve between those points. It allows the TPS to remain accurate even as the sensor wears out.

Someone put one up for sale here a short while ago. Looked at your notes at the time, and a few other references, which indicate the faulty chip is HV825. For reference:

HV825 - Display and LED Drivers - EL Backlight Driver ICs

Inductor Based Single Lamp EL Driver

www.microchip.com

I've not tried one of their chips (my clock is fine) but they offer small quantities at decent prices. Maybe worth trying before shelling out for a 2nd hand clock.

https://www.digikey.com.au/products...pmic-lighting-ballast-controllers/751?k=HV825 If that is the correct chip then is is $1.5 AUD plus shipping.

 

[Navcorr]

Digikey, Mouser, etc. will typically have a minimum quantity requirement for these type of chips.
Usually in the 1000s. Think this is what 2b1ask1 encountered previously.

 

[lambertius]

Ah yes, of course I didn't look properly.

If you identify the correct variation of the chip, I have a colleague who works for Microchip and can ask directly. Also - if you contact a lot of those places directly and ask for 'samples' you might be able to get away with 10-100 (I do a lot of times). I just had a quick search on ebay and found 17 for $80AUD, so I think that it is accessible if you need!

 

[TimR]

The process is just to turn the ignition on and wait 20 seconds before starting the car.

certainly isnt the method that was relayed to me...
I understood it to reset trim tables values....

 

[lambertius]

certainly isnt the method that was relayed to me...
It basically resets all the trim tables AFAIK

I know someone how codes the Bosch ECU that these cars use, I'll ask him but AFIK the trim tables are live based on the knock sensors. Every time you turn off the ignition they reset.

 

[TimR]

Be surprised if they arent constantly being 'trimmed' but not reset...whats the point of that...really ?
A so-called 'adaptive parameter'

 

[2b1ask1]

Someone put one up for sale here a short while ago. Looked at your notes at the time, and a few other references, which indicate the faulty chip is HV825. For reference:

HV825 - Display and LED Drivers - EL Backlight Driver ICs

Inductor Based Single Lamp EL Driver

www.microchip.com

I've not tried one of their chips (my clock is fine) but they offer small quantities at decent prices. Maybe worth trying before shelling out for a 2nd hand clock.

Great link Navcorr, indeed if you scroll down it looks like they don't have minimum orders. At that sort of price it is worth getting say 10 and punting them out.

It is the correct chip I'm sure, just 8 x contacts to dry and then float the new one on. TBH nowt to loose but a half hour sodding about with a screwdriver and a soldering iron.

I didn't keep the PL panel out of mine I don't think, I could have a look on the desk here but it will be 9-years buried! the LED clock is here somewhere.

 

[2b1ask1]

Be surprised if they arent constantly being 'trimmed' but not reset...whats the point of that...really ?
A so-called 'adaptive parameter'

Tim, The adaptive part takes care of fuel variations but more importantly altitude in the mix, on various SM road trips we have gone from sea level to high Alpine passes and back in a day and generally it is imperceptible. We have had princesses that have thrown restart strops though