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Discussion Starter #1
Hi evryone - this is my first timeposting - hope you guys can help me:

2 years ago I got this 89 alfa spider essentially in a box. Just got done putting it together & it will not run. Found that I’m not getting fuel & that the ground pulse is non existant. If I ground one terminal on an injector it will spray – the very confusing Alfa manual shows that power comes from the main relay feeding all 4 injectors & the other leads to each injector are coming from the ecu. Im assuming that the ground switching has to happen at the ecu, but it’s just a solid power from it. Any suggestions?



Thanks so much



Fidel E. Colman
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Welcome! Lots of good info is available here. Run a search for no-start conditions - you'll find plenty of posts.

1. Do you have the Alfa shop manual? I have a copy on CD from CarDisc.com
It includes a step by step troubleshooting section so you can work things out logically & not miss things.

2. The Bosch FI & ignition computers have to get a signal from a pair of flywheel sensors to know that the engine is turning - otherwise they do nothing & you get no spark or squirt. They are easy to test with an ohn meter. You can test at the connections in the engine bay and also at the large connector to the ignition computer (will check the integrity of the wiring).

3. The computers are also sensitive to voltage. If they don't see adequate voltage - again nothing. If your battery is slightly weak (like after multiple cranking attempts), the voltage can drop during cranking to a level below the computer's threshold.

Here's a link to a thread I started when I couldn't get a spark on the 'basket-case' Spider I resurrected: http://www.alfabb.com/bb/forums/showthread.php?t=23817&highlight=flywheel+sensor . There is a link in that thread that goes to other 'no-start' threads. Should give you lots to consider!

HTH, Eric
 

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Discussion Starter #3
no ground for injectors

Eric - thanks for the reply - i do have good spark, just no fuel. I'll be using a scope tonight to see if i have a signal from both rpm & crank position sensors. Also have the paper repair manual, but i'm not very good at reading it yet. all i know so far is that its getting power from the main relay to the injectors & constant power from the ecu. just not sure if the ecu is fried, has a bad ground or if the rpm/crank position sensors are not working. Battery is new.

Fidel
 

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Hey, Fidel! Must have gotten the engine back in.

Just remember that the Bosch system on your Spider is identical to the Bosch systems that are on all of the VW's you work on.

Now, I'm not an expert on this particular installation, but I do know that you need a signal from the air meter before it will start injecting fuel, so make sure it's working correctly (move the plate while looking at the voltage out put- it's a 0-5V signal).

And you need to find out where the engine is getting the crank signal, and make sure it's correct too.

Eric S.
 

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i hav the air flow meter wedged open to simulate the air intake while i was checking thing last night. i'll check again tonight -

ps the only wire i have that is not connected under the hood is a red wire w/a black stripe. comes out of the harness near the intake. it has power when the ignition is on, but low voltage - any ideas where it goes?
 

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You can test the flywheel sensors with just an ohm meter. One of the threads I mentioned previously has the parameters.

Also, forgot to mention - the flywheel must be installed with it's timing mark lined up with #1 on TDC. The mark is very small and the flywheel isn't 'doweled' so it is possible to install it incorrectly. There is some info here: http://www.international-auto.com/index.cfm?fa=ad&aid=24

Also - the FI system is very sensitive to intake air leaks. All incoming air must pass through the air flow meter. Make sure there are no vacuum leaks or cracked/loose hoses. Is the large (black plastic) intake duct in good shape? Some develop cracks in the 'accordian' section.

Eric
 

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Fidel said:
ps the only wire i have that is not connected under the hood is a red wire w/a black stripe. comes out of the harness near the intake. it has power when the ignition is on, but low voltage - any ideas where it goes?
hmmm, on our '84 Spider I was puzzled by a white wire with a red stripe that exited the FI harness. Finally found out that it connected to a pink wire that is in the harness near the hood catch. It may have been intended for an inertia shut off switch. It seem not all cars had this switch.

edited to add a link: http://www.alfabb.com/bb/forums/showthread.php?t=23523

Eric
 

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Discussion Starter #8
I'm really suspecting that the flywheel may be on wrong since i did not pay attention to this detail when i put the engine back together. it looked to me like the flywheel could only go on one way, but i must be wrong since there are documented cases of this being possible. trans is coming out tonight.............
 

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Yes, the bad news is the flywheel can be installed wrong.

Before you remove the transmission, try this: remove the upper flywheel sensor. Position the engine with #1 at TDC. I think that in that position, the small nipple in the flywheel's circumference would be visible through the upper flywheel sensor hole. If not at exactly that positon, it'd be close. If your flywheel is incorrectly installed, that nipple won't be any where near the upper sensor location. (Then you'll have to proceed with removing the transmission.)

Here are some pictures I took a long while ago when another poster needed help finding the timing mark (after a machine shop did some work on the flywheel). Note that the timing mark is very small. For the picture I had wire brushed it and added some paint to make it show up. The nipple thingy is what the sensor senses. It is almost exactly 6 inches of circumference away from the TDC mark. I think that should correspond pretty closely to the upper sensor's position in the bell housing.
 

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Discussion Starter #10
thanks for that very important piece of information. i'll post my findings monday.

thanks everyone for your help!
 

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Viewed from the back of the engine, piston No. 1 at TDC, flywheel mark at 12 o'clock, the pin that triggers the reference sensor must be at 2 o'clock (ie the trigger pin is in alignment with the second bolt from the top bolt in the clockwise direction).

You see the timing mark on top and the trigger pin on the right :

Flywheel timing mark on top at TDC.jpg

The reference sensor hole is located at about 4 o'clock, so if the flywheel is correctly installed the pin is not visible through the hole.
 

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Fidel said:
...ps the only wire i have that is not connected under the hood is a red wire w/a black stripe. comes out of the harness near the intake. it has power when the ignition is on, but low voltage - any ideas where it goes?
Although I don't have an 89 wiring diagram, Alfa has traditionally used a red/black wire is this area of the engine bay for the oil pressure sender. A low voltage reading on this wire would seem to confirm this. The sender is screwed into the right rear of the block above the starter. Is there a wire on this sender? If so, what color is it?
 

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denis said:
Viewed from the back of the engine, piston No. 1 at TDC, flywheel mark at 12 o'clock, the pin that triggers the reference sensor must be at 2 o'clock...

The reference sensor hole is located at about 4 o'clock, so if the flywheel is correctly installed the pin is not visible through the hole.
Better info than my quess! (I should remember not to trust my memory...!)

So, using this info, maybe you can still figure out if the flywheel is correctly installed. First put #1 at TDC then calculate how much to turn the crankshaft in order to put the flywheel nipple near the sensor mounting location. If you are within a few degrees I'd say the flywheel is installed right. Unfortunately there are 5 ways to install it wrong and only one right way (if one were to install it randomly).
 

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Discussion Starter #15
The good news: The flywheel was indeed installed incorrectly. Now i have spark & fuel - of course this was after reailizing that i had crossed the rpm sensor with the crank position when reconnecting to the harness - at that point i lost spark & fuel. After switching the connectors i got spark & fuel.

the bad new: engine still will not start - not even with starting fluid. rechecked ignition timing & crank position - 1-3-4-2 Right?

compression seems good, though at my final test showed 150psi on #1 cyl at midnight last night, & did not check any further since the battery was tired & would have most likely given me an incorrect reading down the line. will be rechecking compression again monday.

ps if i misinstalled the cams, or if slightly off on the valve adjustment, would i get that type of compression?


Thanks Dennis for the picture of the oil pressure sensor wire & the flywheel

Thanks Eric & Eric S for getting me on the right direction on the flywheel & the fuel injection course

Fidel
 

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Fidel said:
The good news: The flywheel was indeed installed incorrectly.
Good news?!? Or is that a typo?

rechecked ignition timing & crank position - 1-3-4-2 Right?
Timing is controlled by the ECU (computer). If you look inside the distributor all that's there is a drive shaft & rotor - no centrifugal or vacuum advance, etc. Firing order is 1-3-4-2. IIRC the distributor turns clockwise. (but see my comment about the worth of my memory...) Is is also possible to install the cam drive 180 off. (The cam drive is off the oil pump.) Position the motor with #1 at TDC and look where the distributor rotor is pointing. (Supposed to be towards the front of the motor.) If not, just install the plug wires where they need to be in order to get spark to the correct cylinder.

i.e., if the rotor is pointing forwards when #1 is at TDC on compression stroke, put the #1 spark plug wire into the cap at the corresponding position. If the rotor is pointing towards the back of the motor, put #1 plug wire there. Then install the other wires following the firing order 1-3-4-2.

compression seems good, though... the battery was tired...
150 psi should be just fine. Most important is that all the cylinders measure about the same.

Remember that the computers must see a certain minimum voltage before they wake up. During cranking the available voltage will drop. A weak battery might give seemingly adequate cranking speed but not leave enough voltage for the computers.

if i misinstalled the cams, or if slightly off on the valve adjustment, would i get that type of compression?
The cams or valve clearances would have to be way off. Remember that the engine is an 'interference' motor, though. IF the cams were way off, valves would be hitting pistons, I fear.
 

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Eric - good call again. The ignition distributor was 180 degrees off. She runs great! Thanks for your help & thanks everyone that helped with this thread

Fidel
 
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