mightymidget 0 Posted March 30, 2008 Report Share Posted March 30, 2008 Hi all,I'm looking to replace my OBD2 2.8 AAA block and head with a 2.9 ABV OBD1 block/head. I'd like to keep my OBD2 management and current loom (+ECU). Wondered if anyone here has done the same and could help me answer a few questions? Besides the extra 100cc does anyone know if the 2.8 and 2.9 blocks are the same? I'm a little concerned that the 2.9 block might have a few missing sensors to run the OBD2 management? (ie, knock sensor, crankshaft position sensor etc..) To keep the OBD2 management I'd have to use my current OBD2 throttlebody, inlet manifold, coilpack, top timing chain cover to delete the dizzy (the 2.9 I looking to buy is the older dizzy type). I plan on using the 2.9 head with my OBD2 top cam duplex gears to ensure the camshaft sensor is the same. Anything else I'm missing here? Did the older 2.9 have EGR (exhaust gas recirculation) ? Hope someone can help clarify, Cheers, MM. Link to post Share on other sites
Lizard Racing 0 Posted March 30, 2008 Report Share Posted March 30, 2008 Same block but 82mm pistons. Everything you said is correct. Not sure why you need to change the head though if you just change the timing case, single or Duplex will run the same so long as you have the pickup on the cam sprocket. Cant help with the EGR valve, possibly blocked off some how. Link to post Share on other sites
mightymidget 0 Posted March 30, 2008 Author Report Share Posted March 30, 2008 thanks for your reply. I'm looking to replace my worn-out 2.8 with a recon 2.9. The head on the 2.9 has been rebuilt so wanted to throw that on along with the block. Not really looking for any performance gains. Does anyone know if the 2.9 ran EGR? if so I guess it's just a matter of blocking off with a cap to run my OBD2 mani and TB. Still a little concerned that the 2.9 head/block might have some missing sensors even with my OBD2 attachements. Link to post Share on other sites
UnitedMotorsport 55 Posted March 30, 2008 Report Share Posted March 30, 2008 2.9 Engine has ALL the snesors OBD2 requiresIf the 2,9 is from a UK Corrado, there will be no EGR to worry about. Link to post Share on other sites
mightymidget 0 Posted March 30, 2008 Author Report Share Posted March 30, 2008 thanks C2 MS. Much appreciated. That's twice you've answered a question for me this weekend Link to post Share on other sites
FishWick 21 Posted March 31, 2008 Report Share Posted March 31, 2008 US cyl heads have a secondary air injection port at the front between cylinders 4 and 6. That is the only difference (mechanically) between US and Euro 12V engines. 2.8 and 2.9 parts are all interchangable.The 2.9 was cobbled together to get the Corrado up to 145mph for marketing purposes. I prefer the 2.8 engine myself, in OBD2 flavour. Link to post Share on other sites
matty.vrt 120 Posted March 31, 2008 Report Share Posted March 31, 2008 ive just converted a 2.8 obd2 to 2.9 block + head it runnes fine but i made the mistake of putting cams in at the same time so i dont no wether it isnt idling because of the cams or the fact its running a 2.8 fuel map,ignition etc..... Link to post Share on other sites
mightymidget 0 Posted March 31, 2008 Author Report Share Posted March 31, 2008 ive just converted a 2.8 obd2 to 2.9 block + head it runnes fine but i made the mistake of putting cams in at the same time so i dont no wether it isnt idling because of the cams or the fact its running a 2.8 fuel map' date='ignition etc.....[/quote']thanks again everyone for your input.matty - Have you had it on a VAG-COM to check for error codes? It would be strange if the extra 100cc caused it not to idle.. You might need to do a TBA (throttle body adaptation) or possibly reset the ECU to get it to adjust to the new cams and additional capacity.Certainly like to see if you can get this sorted before I proceed along the 2.9 OBD2 route. Anyone else have any ideas as why matts idle has disapeared?? Link to post Share on other sites
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