Alfa Romeo Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hi All.
I have just bought a 146 TS, it had a suspected blown cambelt, bought it sight unseen. Checked it over and sure enough. So decided to buy 2nd hand engine, which when it arrived, happened to be the plastic top type, thought no problems changed everything over except cam sensor as I did not want to remove cambelt.
The car goes, but it hunts at idle. My first thought was airleak, but cant find one anywhere.
My scan tool does not have the Fiat 3pin plug adaptor. And the check engine light is on, so possibly a sensor? Im thinking oxy sensor, but I disconnected it and after a further while it hunts again, disconnecting throttle sensor makes it stop but idles at 2000rpm. Allowing air into throttle body bypassing airflow drops the idle. Vacuum gauge reads between 15 -20 inches as idle hunts. Have sprayed brakeclean around manifold but seem to make no differance in running.
Have been reading the forum and see about throttle reset, but does it work on alloy top?
I already own a 146 Boxer eng and am keen to try the twin spark:)
 

·
Registered
Joined
·
8 Posts
Discussion Starter #2
Found a snapon ethos scan tool that would talk to it and fault came up with phase sensor, (cam sensor?).
Have tested sensor with LED on trigger wire and is working. Check the sensor off the old engine and configuration is the same. Im now thinking that position of sensor between alloy top and plastic top engine may be different, OR there is more than one gap in the sprocket on the later engine? Will have to pull covers off to check.
Update on hunting, was unable to purchase idle valve, or I could ex Italy $800, via the agents or a Bosch one $450 plus $150 freight bill.
So had another look and used a screwdriver to move the spindle and managed to get it to move, the more I played the more free it become, now is back in vehicle and is now constant idle at about 900rpms.
 

·
Registered
Joined
·
1,503 Posts
Plastic top and alloy top engines have different camshaft sensors and the cut outs in the back of the exhaust pulleys are also different. You can't use a plastic top camshaft and pulley with the ECU from an alloy top (and visa versa). This is why you will be seeing a cam sensor fault in the ECU.

There are some pictures of the different exhaust cam pulley cutouts somewhere. I'll try and find them for you.
 

·
Registered
Joined
·
1,503 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #5
Thanks for that, just hopped online to post the fact that I had to change exhaust cam sprocket. And yes there is only one cutout in alloy top as opposed to multi cutouts in plastic top. My engine light is now out.
Incidentally I did not have cam locking tools, but lifted two cam bearing caps on each cam put a piece of cardboard under bearing caps and nipped them back up again then used rattle gun on cam sprocket bolt, held onto belt then slipped other sprocket on. Wound up the tensioner again which the only thing that bothers me, I dont think the tensioner will overtighten the belt? will it?
About to test drive, finally.

Thanks for your reply and help.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6
Update. While doing the test drive a whine developed under the bonnet, dropped fanbelt and cam cover and sure enough tensioner, so changed tensioner and idler, problem fixed.
Unfortunately had only just reassembled so didnt want to remove rocker cover again. So made up a bracket with two holes to screw into inlet cam sprocket and cable tied to engine mount, to remove tensioner and idle, did one at a time so didnt drop belt altogether as I had marked everything while at TDC. Bit bodgey I know but it worked.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
Just incidently I would say that my boxer 146 sounds better and seems quicker of the mark than the twin spark 146.
 

·
Registered
Joined
·
1,503 Posts
You may find your lack of performance in the 146 TS is down to the way you've done the belts. Without the cam locking blocks it's quite easy to get one of both of the cam pulleys a tooth out (that's also not to say they might have already been timed up a tooth out before you got the car so it might be a previous mechanics fault if they didn't have any blocks). I know of other owners whose cars have been timed up by garages without the proper cam locking blocks and the car has come back lacking in performance. A re-time using blocks has sorted the issue. If you're intending on keeping the car for a while then a set of blocks are certainly worthwhile investment and they can be picked up quite cheaply these days :)

To get the correct tension there is a special tool available but you can safely improvise quite easily with other methods. The important thing is that the pointer on the tensioner ends up "hovering" around pointing to the hole in the tensioner mounting when the engine is idling.
 

·
Registered
Joined
·
1,503 Posts
Ahhh...OK. Thought you were in the UK as I saw your county was shown ad Canterbury but completely missed your country stating NZ :D

Not sure what shipping costs are from the UK to NZ but you can get some from TotallyAlfa.
 
1 - 10 of 10 Posts
Top