BBY to BBZ change

C

coullboy

New Member
Guys I have a problem. My BBY 1.4 petrol engine died earlier this when low oil pressure took its toll. I found another BBY and found out that there are two variants of this engine! One to suit a 085 gearbox (Lupo etc) and one to suit 02 gearboxes, such as the A2. So the search started again. I found a BBZ engine locally and after a bit of investigating I found the block and head to be identical, but with bigger inlet manifold injectors and throttle body (100hp over the BBYs 75hp). So I changed everything off my old engine inc the sump and all ancillaries And started it. All good to begin with sounding good, good oil pressure and free reving. Pretty much as soon as it warmed up a bit it would not idle, then the EPC light came on. I checked on VCDS and found the codes
17961 - Barometric / Manifold Pressure Signals
P1553 - 35-10 - Implausible Correlation - Intermittent
17912 - Intake Air Sveter
P1504 - 35-00 - Leak Detected

Ah an air leak I hear you say. Nope. I have tried every possibility to find the cause of a leak. Mostly by capping off everything on the inlet manifold. So at that point I figured it must be the throttle body, so I changed over to the BBZ bigger inlet manifold, injectors and throttle and re plumbed.
This had the very same symptoms and fault codes. It also trips the EPC light. Quick one here… why does the EPC not show up on VCDS in Engine fault codes??
Anyway I’ve given up for the night! I’m 20 hours in and very frustrated!

I would love to know how these engines ‘close the loop’ without a MAF sensor. I assume it’s down to the MAP sensor. Is there some Other form of load sensor?

Any help would be appreciated
 
I figured that with me changing all the parts over to the BBY engines sensors, it was effectively a BBY. I don’t have the BBZ engine ecu so I can’t test it. Sadly.
 
this sounds like a variation on the AUA to AUB / BCB hybrid (now owned by @George Hogg ) that was initiated / undertaken by @celsisone - although Brett I think started by using the AUB ECU so that the control unit could "cope conceptually" with using the larger throttle body and higher rev limit as well as sensor feedback that would make sense to the higher performance engine.

I think Graham (@audifan )'s question above has come from the same vein of thought. Can you obtain a compatible ECU for a later / higher performance engine with suitable immobiliser deletion? I wouldn't have thought these would be too expensive given the age.
 
I’ll maybe have to go down that route. I still can’t see how with all the original BBY sensors and throttle etc fitted, why it won’t run reasonably well.
 
And all this is before we even consider different exhaust design and sensors, cam size and timing, valve size etc. If it ran as a BBZ then do so again and only swap the absolute minimum over, but would probably look for a compatible exhaust and certainly ECU.

At the end of the day it will no longer be a type approved A2 and that has implications with insurance etc If you were not intending to tell the insurance company then that is illegal even fraud..

So either get a BBY engine or get another car.
 
Don’t tempt Maurice with “the other car”!!!
Insurance was an easy thing for me and I’m sure it will be for Maurice as we’re not in the boy-racer age group Graham! Lol. Maurice also has a number of “interesting cars” so he’d be able to get collectors insurance.
Maurice I didn’t realised you’d swapped engine type but it seems worthwhile trying an ECU for that engine even though you’ve swapped sensors. If you now have a 100hp engine I’d imagine a 75hp ECU is having difficulties. Is it a Bosch or Magnetti Marelli ECU?
 
Robin_Cox said:
Plenty of BBZ ECUs on Ebay for £25 to £40 quid from Ibizas and Fabias. @George Hogg - they are Magnetti Marelli just like our AUA.
Click to expand...
For what it's worth, I think the BBZ will need the originals injectors, sensors, etc, to run correctly, (and give 100 bhp), with it's own ECU. Engine, and ECU especially the fuel and ignition mapping are an entity, not pic'n'mix.
Mac
 
My BCB/AUA has the AUA ECU and an updated pressure regulator to run best but yours seems to be a worse than “not running absolutely spot on” from your description and the screenshot you sent.
Any ideas gurus?
 

Attachments

  • IMG_5257.jpeg
    IMG_5257.jpeg
    915.9 KB · Views: 77
You must log in or register to reply here.
Back
Top