Alfa Romeo Forums banner

1 - 20 of 35 Posts

·
Registered
Joined
·
1,426 Posts
Discussion Starter #1
I am about to order up a new ignition ECU for my Spider, it has been giving me problems since I bought it 2 years ago. Once it is running, it does great, no issue, but every once in a while, it won't start, and I have confirmed this as no spark. I replaced everything under the hood ignition related, coil, plugs wires. I have tested both the flywheel sensors, always test correct. I have tested both the relays by the ecu, I have tested the vacuum sensor. It has been getting worse, so now it is in front of the house and just won't start. I put a new battery in it over the winter, and I have tested the voltage at start, at the junction under the hood, I am getting 10.9 volts when the engine is turning over. Is there anything else that it could be? Is there a way to test the ecu? Where can a buy a new/reman ecu? Anyone have a spare one I can test with to confirm this is it?
 

·
Administrator
Joined
·
16,405 Posts
10.9V is near the ECU's 'wake up and get to work' threshold (generally asserted to be ~ 10.3V to 10.5V). Our Spider (1984) reads 12.6V with everything off and ~ 11.8V during cranking. I'd suggest a careful investigation for voltage drops - iffy connections, corroded terminals, loose crimps, etc. A tenth of a volt here and a tenth of a volt there could add up and conspire against you. And some might be intermittant such that only when they are all acting up does the car fail to start.

My brother is into old jeeps but he has a page about electrical stuff that is universal enough to apply to our cars. It includes info about 'voltage drop testing'. (and if you have some time to waste, browse around his 'marriage & jeeps' section - some of that will apply to Alfa's, too.)
 

·
Registered
Joined
·
1,960 Posts
It may be the ECU, if you need a "check spare" I have one.

I bought one on eBay and I suggest you do the same. They run average $150 or so sometimes more sometimes less.

The most "friendly" scenario is for you to send it to someone to try in their cars. Most people would be leery to send out an ECU for trial in a car at "arms length".

I note that Vick seems to have a swap service, you may look into that. There are other ECU places that advertise "repair", but I would be very scheptical.

My thoughys, Elio
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #4
Thanks for the help, I will will give the Jeep page a look, I do have an 89 Grand Wagoneer, so it will be good info. I have done quite a bit of ground and eletrical cleaning, but I can always do more. Another thing that makes me think it might not be the volt drop is the fact that sometimes when this happens, I can crank on it for a while and it will start up, even after about 30 seconds of cranking. It really acts like a relay more than anything.

I will give Vicks a call on Monday, price the rebuild service, I think that maybe the way to go if infact it is the ecu...
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #5
Can anyone tell me where the ignition ECU gets the volts reading from? I think that pin #4 on the ignition ecu gets the volts reading, but from where? Is it the fuse box? I read on an old Alfa Digest that it comes from the starter solenoid, any truth to that?
 

·
Administrator
Joined
·
16,405 Posts
Send esteemed BB member PapaJam a PM, include your email address and ask for copies of his excellent color-coded wire diagrams. He will reply with some attachments that will make figuring out your Spider's electrical issues much easier.

Off hand, I think the ECU gets its electrons via a green/black wire off the fuse box. But, since that tidbit is via memory and I have CRS disease, verify that before proceeding further.
 

·
Administrator
Joined
·
16,405 Posts
Below is a snip from PapaJam's wire diagram for the ignition ECU (his chassis diagrams are all color coded). And also a snip from the Alfa Shop manual re: ignition ECU testing. Note the tests described in the shop manual are not directly to the ECU but rather on the female sockets in the wire harness - disconnected from the ECU. Do not use an ohm meter on the pins on the ECU itself. AFAIK, there is no practical test of the ECU itself. If all sensors and inputs test good, the only thing left is a faulty ECU. But before you rush to condemn it, make sure everything else is 100%.
 

Attachments

·
Registered
Joined
·
1,426 Posts
Discussion Starter #8
Sweet!!! Thank you very much, any idea where the violet wire attaches to the ignition switch? I had problems with my starter, even after a new starter and switch it would still sometimes not start, so I installed a relay, I wonder of the same "not enough juice" to start the starter is keeping the ecu from firing....
 

·
Registered
Joined
·
174 Posts
SamW:
I am experiencing the same problem. I have redone all of my grounds, etc., etc.

How do you test a relay? I need to test the two next to my ECU. I bought a new main relay, but that was not the problem, so now I have two of them. And, how do you test the flywheel sensors and the vacuum sensors. If you would prefer not to take up space with your reply, then PM me at mandlebaum at sbcglobal dot net.

Many, many thanks
Dean
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #11
Eric,

OK, I guess my question is how do I get from the black wire on the switch to the starter solenoid to the voilet wire going to the ecu? They have to connect somehow, am I thinking about this right? Does the voilet wire splice into the black wire?

Thanks for the help!

Dean,

If you have a couple of wires, unplug the simple relay and get a spare battery (I keep a little motorcycle battery for stuff like this) hook the positive side of the battery to pin 85 (it should be marked on the relay) and the negative side to pin 86, then check the resistence between 30 and 87, should be no resistence when 85 and 86 are hooked up to the battery, if you unplug one from the battery, 87 and 30 should be an open line. As for the vacuum, I just listend for this one, you should hear it click when you start spinning over the engine and then click again after the engine stops spinning with the starter. I did not check to make sure it worked, I assumed it was working because of the click. For the flywheel sensors go to hiperformacestore.com and look under the Spider L-jet, he gives a really good description, you test the resistence between two of the three pins, but you will need his photo and range to get it right. I don't mind sharing the post, we are chasing the same thing!
 

·
Administrator
Joined
·
16,405 Posts
A relay is essentially an automatic switch. A 'trigger' signal energizes a small electromagnet which then makes or breaks internal contacts to 'relay' the signal to make something happen. The other relay (called the drive relay) in your Spider is a little odd in that its trigger is a tachymetric signal (pulsing) from the coil. The tachymetric signal tells the drive relay the engine is running (as the coil charges & discharges to make sparks) and the output from the drive relay powers on the fuel pumps. If the drive relay does NOT see a tachymetric signal (engine not running) it turns off the fuel pump's power supply.

So, to test a relay you need to check for input (the trigger signal) and output (what ever the relay is supposed to make happen).

To test the flywheel sensors, peruse the Spider L-jet diagnosis page. Link is in my signature.

The most common problem with the vacuum sensor (aka MAP sensor) is that it leaks (will not hold a vacuum). Does your's moan, groan or whistle? If so it is likely leaking. BTW, be sure you are sitting down when you check the price of a new vacuum sensor...
 

·
Administrator
Joined
·
16,405 Posts
...how do I get from the black wire on the switch to the starter solenoid to the voilet wire going to the ecu? They have to connect somehow, am I thinking about this right? Does the voilet wire splice into the black wire?
Yes, up under the dash next to the stering column you should find where a short cable exits the column surround. It has two connectors, one with two wires (a third spade connector is not used), the other with one wire. The violet wire splices in where the black wire connects to the short harness from the ignition switch.

If your model Spider has the knee bolsters they may be somewhat in the way. But that is where the purple & black connect.
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #14
Ahh!!! That is what I was looking for, someone (PO) installed a serious stereo and they spliced wires all under the dash, I have been slowly putting them back to normal as I find them, I replaced the switch, so I should be able to find this, I was not sure if I needed to start looking at the fuse box or under the hood. Thanks again!! After work, all these test will be checked and I will let you now what I find!!!
 

·
Trained (ex)Professional, , 1953-2018 RIP,
Joined
·
16,232 Posts
Sam,
The diagram in post #9 has an error in that the violet wire should connect to the ignition switch connector in location #1 (wire #50), NOT #2 (wire 15/54). The diagram has since been revised to correct this error.

If the violet start signal wire on your 89 is like the 86-88 Spiders, this wire does not go directly to the ECU. It first makes a stop at terminal 87b of relay N10 (interior light timer) then makes it's way to connector G121 located behind the glovebox where it then splits 5 ways; one each to the ignition & fuel ECUs, one to the Thermo Time Switch (TTS), one to the Cold Start Injector (CSI) and the fifth goes to terminal #50 of the drive relay (to energize the fuel pumps during cranking). Since this is from memory, I'll check the diagrams this evening to be certain.
If you'd like the diagrams for an 88 Spider (if not seen Alfa published diagrams for an 89), please PM me your email address.
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #16
Thanks Jim, corrections noted! I sent you a PM, but I will keep the thread going for the benfits of others who might follow.

I think my '89 is an early one, I have the L-Jet fuel system. Is the N10 relay in the fuse box? My interior lights don't turn on unless you do it manually, so it is worth looking at that too. The G121 connector, when you say it is behind the glove box, can I get to from under the dash, or am I going to have to pull the glove box out again like I did when the cowl drain hose split?
 

·
1966-2013
Joined
·
13,741 Posts
Is the N10 relay in the fuse box?
Yes.

My interior lights don't turn on unless you do it manually, so it is worth looking at that too.
Before getting all happy about trying to find the all but unobtanium, and horrifically expensive if you do find one, you might wanna check/clean the contacts at the doors and make sure that the lamp housings are actually wired correctly as the lamps can indeed be mis-wired and still work as you describe. (door switches are just grounds, or rather contacts that engage ground when the door(s) are opened)
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #18
OK, I went through all the test and everything came back A-OK, so I guess I have a dead ignition ECU... Anybody got a Bosch 0-227-400-003 for sale?
 

·
Registered
Joined
·
1,426 Posts
Discussion Starter #20
Anybody have a picture of a series 3 fuse box? I looked at mine and I have a normal silver realy where the linterior lights timer is supposed to be, I am guessing that the longer black relay next to it is the interior light timer, but given that one is out of place, I want to make sure the others are correct... ([email protected] POs!!!!)
 
1 - 20 of 35 Posts
Top