No pulse to FI

[JoeRealtor]

Hello all and thank you in advance for your assistance. Here is what I have, 82 Spider with no pulse to FI. Already ran through the diagnostic and had issue with #19, showing need for new ECU. Had a spare but does same thing. Car starts off of cold start valve and runs for a few seconds then dies. Fuel Pressure is 32. AFA turns on pump. Just no pulse. Changed out dual relay and still nothing. At a loss. I don't think it is very common to have 2 bad ECU's. Any ideas.

Btw, have good pulse to cold start injector, just nothing to any of the other injectors.

[narfire]

How are the two ground conections on the intake plenum?

[JoeRealtor]

Pulled them and added new connectors and reattached and still not pulse. Then tested to ensure they where grounded. Ran light tester from hot source and was able to complete circuit when touching either wire.

[So Cal Mark]

are you getting a signal from the coil to the ecu?

[JoeRealtor]

Well, I am assuming that part of the diagnostic testing of the relay and ECU harness was for that. Of course, you know what they say about assumptions. How do I test to see if coil is sending signal to ECU?

[So Cal Mark]

the relay merely supplies power to the injectors. the ecu grounds the injectors. If the ecu doesn't see a pulse from the - side of the coil, the injectors will never be grounded. You can use a test light at the - side of the coil and check for a pulse when cranking, then check the other end of the wire from the coil to the ecu

[JoeRealtor]

Both the neg and pos post are hot when the key is in the on position. When engaging the starter, the test light does appear to pulse, but is there suppose to be power coming out of the neg post even when in the on position? Current wiring of coil is pink wire, red wire and yellow wire to pos post. Two black wires and brown w/white strip to neg.

[rlux4]

The brown with white wire is the one Mark asked about. It signals the ECU that the coil is pulsing.
Is this a new problem, or is this a new car to you?
If it's a new problem it's usually the result of whatever was done last to a car.
Can you give us some background on your car?
The FI diagnostic I use also said my ECU was bad at some point in the process when in fact it wasn't. It seems like the manual should have said at that point "the ECU may be bad".
If the two grounds are solid on the intake plenum, then I'd check that your pigtail at the ECU is securely snapped in.
Waiting to hear from you.
Ron

[JoeRealtor]

I have owned this spider for about 12 years. Before this one, I owned a 79 Spider and a 4 door 1972 128. Have always loved Fiats. Was driving it last summer and it just died while driving down the road. Had it towed to a shop and the mechanic had not clue (in North Carolina). He said, "this is one of them foreign jobs". LOL. So, towed it home and parked in garage ever since. Only thing mechanic did was put a new coil on. In the last 12 years he was the first mechanic to touch her. Thus far, I have been able to fix everything that went wrong. She was very dependable. Even use to drive her from Fort Bragg, NC to Fort Jackson Sc, every weekend while in school.

I thought the brown and white wire went to the tachometer and the pink one to the double relay. Still don't know where the yellow one goes. Have not been able to find it on any wiring diagram. When engaging the starter the light gets brighter on the brown wire, but can not really say I see a pulse. I have checked the ECU pigtail several times. It is secure.

[JoeRealtor]

Ok, rechecked the ECU pigtail harness. Using a light tester to terminal one and then to ground, the diagnostic say it should pulse when engaging the starter. In fact I get power to the #1 terminal with the key in the on position and it actually dims when starter is engaged. I believe that terminal one is the coil wire according the the wiring diagram. So, bad coil or control module? Both, neither or am I dumber than a 3rd grader?

P.s. please don't answer the last part of that question, there are some things better left unanswered.

[wikkid]

You can have your control module tested at an auto parts store. If it is bad, it is a standard part - the Autozone place I went had one in stock, though they tested my old one and found it checked out fine.

[rlux4]

I had a similar experience with a "mechanic". Now I'm like you, I do it myself.
Do you have Brad Artigue's electrical diagrams? They can be printed in any size, my 11X17 are very easy to read.
http://www.artigue.com/fiat/wiring-diagrams
It does show that the brown w/ white wire goes from the coil to term. #1 at the ECU
So it sounds like you're on the right track with the ignition pick up. Look under the dist. cap and see if the wires are toast.
Have you tried to see if you're getting spark at the plugs?
Ron

[JoeRealtor]

Yes, I have that wiring diagram, thanks. Getting spark. In fact it runs for about 3 to 8 seconds off of the cold start injector. Is it normal to have power at the neg on the coil when key is at the on position?

[So Cal Mark]

yes, that shows the coil has continuity. Since the coil was replaced, make sure it's wired properly. Without the - signal from the coil to the ecu the injectors won't ever be grounded

[JoeRealtor]

Picked up at new coil and control module just to be safe. Going to install tonight and check ground. Wish me luck.