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Discussion Starter #1
On the flywheel, on an 89 injected model there is a pin or dowel that triggers the ignition computer. My question is: is there one or two of these pins? A picture would be nice?
 

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Yes, there is a small nib (not sure what is the correct name) for the position (timing) sensor. I think the speed (RPM) sensor 'reads' the ring gear's teeth. And thus there is a specified orientation to install the flywheel (it is not doweled to the crankshaft - it can be installed in six positions - five wrong & one right).

For more info about the L-jet system in our cars see the link in my signature.
 

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Discussion Starter #3 (Edited)
Thanks, I installed the flywheel as per the Alfa manual. So there is only one pin on the flywheel? I built the engine a few years ago then I pulled apart the engine in my 87, parts car, there are two pins 180 out from each other? So I’m confused. This engine ran well too?
 

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that second 'pin' is just a bolt some PO stuck in there.....that isn't original (but why is it there is the question?) Perhaps a PO put it there to somehow lock the flywheel and forgot to remove it after he was done?

I have taken the liberty of showing your photos below, so it is easier for others to see and comment on (rather than opening a link each time)
first photo is factory pin at 9 oClock
second a bolt at 3 oClock

link below shows timing mark and pin in relation to each other:
https://www.alfabb.com/bb/forums/213088-post11.html
 

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Discussion Starter #7
Thank you for posting the pictures for me I use an I pad and I’m not too savvy With this type of stuff.

So the engine pictured came out of my 89 spider. It was running fine at the time. I removed it along with the transmission, due to the loss of first and second gear. Me being the hot shot master mechanic that I am( sic), I decided to pull the engine and transmission out of my rusty but complete 87 spider. I replaced the clutch and had the flywheel machined. Put it all together and installed the 87 in the 89. There are very few differences between the model years. When I got it started only two cylinders were firing. That’s about where I stand now, other than checking each sensor, disconnecting wiring harnesses to ring them out and checking many of the grounds. Haven’t had a lot of time in the garage lately but would love to make some headway by spring.
 

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When I got it started only two cylinders were firing. That’s about where I stand now....
which cylinders are not firing?

I am not so sure the ignition ecu would be at fault if you have 2 cylinders firing. And if one of the flywheel sensors were bad, I think you would have a no start.

check if you have spark on all 4 cylinders (if not, might just be a bad lead, or plug or two.....it can happen!)

you sure you have the firing order correct? (if dizzy leads were removed and replaced in the wrong position, for example. check for 1-3-4-2 firing order)

if spark is on all 4 (and leads and plugs are confirmed good........you can swop over some to test) then you should either be looking at very low compression on those 2 cylinders, or, a fuel issue (clogged injectors, injector signal, injector connector plugs etc)
 

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Discussion Starter #10 (Edited)
It is consistently firing on two cylinders. Plugs are out so I can see them fire or not. Swapped cap, rotor, wires and plugs from another working engine. Same result. I’m at my wits end, very close at least. I have a spare ignition computer but don’t want to risk damaging that because I may be missing something. Well at least I have till spring to figure this **** thing out. Firing order at this time is not important because they are removed for trouble shooting. I may reinstall the previous flywheel just to make sure...
 

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if all 4 plugs are sparking, and you have fuel, then it sure sounds like the flywheel is not aligned correct (although you say you installed it per the book)

it would spark and you'd have fuel, just not timed when you need it!

iirc: when the flywheel timing mark is up at 12 oclock, the little magnetic nub should be at 2 o'clock
(I believe the trigger pin/nub is actually magnetic, so that bolt a PO put in the other flywheel probably is not doing anything!.....but someone correct me if I am wrong)

one way to be sure, is to look for the flywheel bolt hole (there is only one with slightly recessed threads) and align this to the TDC flywheel mark....see photos here:
https://www.alfabb.com/bb/forums/6824673-post16.html

but only go by the factory mark.....don't rely on paint marks unless you are sure they too aling with the factory mark.

For instance here on the photo of your odd "2 pin" flywheel, there is a paintmark (I circled it red) and if that is supposed to be the TDC mark, then the timing nub (circled in yellow) is a 9 o'clock, not 2 o'clock!
In fact, I would almost hazard a guess that the faded paint mark (green arrow) is aligned to TDC......so paint marks themselves need to be double checked before assuming what they are for;)
 

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Discussion Starter #13
There are only two plugs firing. All plugs are connected to the wires and sitting on top of the engine. When I crank the engine only 2 plugs fire. Number 1&4. With two sparks per revolution It’s like the computer skips a revolution. The engine, when I put it back together, starts up but runs, well like it’s on two cylinders! Compression is even across all four cylinders. I forget the value though. I swapped the magnetic pickups too, no help. I’m lucky to have two complete cars for trouble shooting. I’ve gone through a lot of cigars leaning over this baby, that’s not a complaint. Man am I gonna know how this things works by the time I’m done.
 

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how odd. you swopped cap rotor and leads from the other car, so leads are likely ok.

the only thing that distributes the spark is the rotor in the distributor. The coil gets the tachymetric signal from a single white wire from the Ignition ECU (pin #1) to coil negative side (check. you have the whites on the coil negative?)
The coil is obviously delivering a spark to the distributor (or you will not have any spark at all)

You presently have plugs #1 & #4 sparking:
try swopping over lead 1 & 2 on the distributor cap (yes, you are putting them in the wrong order, but just do it to test)......is sparkplug 2 now sparking and 1 not? in other words do you now have plugs 2 & 4 sparking?

I have never heard of this before, but sounds likethe IGN ECU is only pulsing half what it should.

In which case swop over the IGN ECU from the other car.
Check though first, is the IGN ecu the correct one?: Bosch # 0 227 400 003
 

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Here's a helpful post from @ghnl on another thread on AlfaBB:
flywheel installation

...and a photo from my engine rebuild thread, showing all the marks to mechanically time the engine:


I looked through my camera to see if I had a wider-angle view of the installed flywheel that shows the magnetic pickup, but I don't. @ghnl's photo with the tape measure should help with the magnet location.
 

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I looked through my camera to see if I had a wider-angle view of the installed flywheel that shows the magnetic pickup, but I don't.

the link in my post #6 above has a decent photo...TDC mark at 12, pickup at 2

@ Farina? any further news?
 

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Discussion Starter #17
I swapped the ignition computers and no help. the part numbers are the same too.so next...I don't know just what to do next. i may reinstall the old flywheel, in spring! the number 1 and number 4 spark plugs fire away just fine.
 

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You said the 89 engine was running fine, just had a transmission problem.

Was the 87 engine also running fine prior to the swop into the 89 spider?

do both engines still have the original bosch distributor (so nothing inside but a rotor)?
 

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Discussion Starter #19
The 87 donator car had a blown head gasket. Both cars were a “gift” from a friend of a friend, who’s wife gave him an ultimatum! My wife still likes the cars, for now. The 89 always ran. I could expound further on their history’s but I think that is enough for this discussion. I consistently fire on 1 f 4, the distributors ore with their original engines. Now you’ve made me think about swapping them for fun! It is getting to the point where I may put the other flywheel in this engine. Have I obfuscated the problem enough?
 

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Discussion Starter #20
Could it be weak coil? It’s only firing one per revolution. Just sitting here thinking and looking at the wiring diagram. I could be full of it too!
 
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