I converted my brother's T12 Bluebird from the carby CA20S setup to CA20E. In practice it meant to replace the entire electrical system, the fuel tank (pump's in the tank now instead of in the engine bay) and the head and intake manifold + ECU installation. The car's completely assembled now and all the accessory stuff works perfectly. Wipers, lights, interior fan, rear defogger etc etc.
All parts are stock parts, there's no fancy custom aftermarket stuff under the bonnet of this T12. Except for a hose to a vacuum meter.
![Razz :P](./images/smilies/icon_razz.gif)
To get to the point; the engine starts up and runs on all 4 cylinders but it gets way too much fuel. The smoke cloud coming out of the exhaust looks like the soot coming out of a truck exhaust when it's -30 degrees centigrade outside and the truck engine is cold. A lot of black stuff, almost enough to cover up an entire unit of soldiers.
![Razz :P](./images/smilies/icon_razz.gif)
In normal "closed loop" running mode the ECU reports no errors (red led doesn't blink nor light up) except for a rich condition in the exhaust (green led is off). When I put on the ignition, before I crank the engine, both leds light up so the ECU is getting all the power it needs and seems to be working properly. But some nut has disabled the diagnostics screw so I can't change ECU mode to check for error codes.
![Crying or Very sad :cry:](./images/smilies/icon_cry.gif)
Giving the engine some revs (for example up to about 2500) makes it give the engine even more fuel when the pedal is pushed so apparently the afm is operational, as is the throttle sensor. After a while the engine starts to splutter because of the constant rich condition. I've tried changing the exhaust gas sensor but that had no effect. Also, the intake vacuum is very low at idle (10-15 inHg) and of course a bit unstable too.
I'm thinking fuel pressure regulator failure, since everything else seems to check out. I took it out and tried to operate it... but the valve did not move at all. It seems to be stuck. Putting some pressure (below 0.2 bar, didn't want to blow up the diaphragm) on the vacuum side made it close, so I thought maybe it's OK to put it back... only to realize the valve must have opened completely, stuck open, and let through way too much fuel pressure because the engine was still running rich after exercising the regulator.
There is another thing I have been thinking about: we didn't change the crank and rods and pistons, just the head. So the compression is a whopping 9.6:1 (which is standard on the CA20S) instead of 8.5:1 which the CA20E should have. Plus the engine displacement is 1960cc instead of 1974cc which the CA20E should have. Can this cause rich running conditions too?
I haven't ever had an EFI car before, so I really don't know if I'm at it or completely lost. The guys at ZXOC couldn't help me because the CA20E is rather unusual in the UK. Well, it's unusual over here too so I don't know any people in my country that can help me out. So I thought maybe some of you petrolheads at this forum might be able to help me out, even though this is not a N12 but a T12.
I'm open for comments and suggestions. I need to get the engine running properly ASAP. I don't think it'll be long until this problem is solved, since the engine is running on all 4 and always starting up without problems. But where to look for the troublemaker; that's the big question.
I've got a workshop manual for the CA20E engine, but unfortunately it does not tell me where to start with this kind of a problem. And the manual is for a S12 Silvia so it differs on some points.
Cheers,
Jan