bad double relay or ECU?

[BTCTheReaper]

Hello all,
I was hoping I could get some feed back on this problem i'm having. The car is a 82 pinin spider. I just rebuilt the engine and reinstalled it and but I can't get the injectors to fire. I was getting a spark, the engine would turn over, and start off the cold start valve. but would only run for like 1/2 a sec. After reading through all the posts in the Electrical threads, I found the EFI diagnostics tests, http://www.wcmotors.com/personal/Fiat%2 ... agnostics/. I went through those steps and the double relay failed step 15, so I ordered a new relay from IAP. After installing the new relay it still would not start, the injectors were still not getting a signal. This is were it gets strange, i now noticed that the fuel gauge, radio, turnsignals, braked lights, backup lights, horn, and ignition coil were not wroking. First i checked all the fuses(including the 3 inline fuses, yes my car has 3 factory installed inlines under the dash, the 3rd is located above the o2 sensor rest box), checked all the grounds under the dash, in the engine compartment and on the trans. All of them were fine. So now I did the EFi diagnostics steps again, and did not get past step 14. So i checked the wiring with a ohm meter between the relay set and the ignition. the wiring is ok. So now, just out of thought, i tested the ignition switch it self. The switch is ok. So now i put the old relay back in and ran the diagnostics again it too does not pass step 14, before it would get up to 15 before it would fail. Well after pouring over Artigue's wiring diagrams i noticed that the brown wire at the relay fed directly from the battery and the pink w/black stripe at the relay goes to #1 fuse as well as to the ignition, in the ignition the pink wire only contacts with the black wire. i tested the black wire after the ignition and it is ok. So at the relay i put a jumper between the brown and pink. Presto, fuel gauge and everything else that was not getting power is now working. it stiil would do the same thing when trying to start, only getting fuel from the cold start valve, no signal at the injectors. It does the same thing with the new relay when a jumper is used, no signal at the injectors. but with out the jumper none of the previous things get power. So with the jumper in place I ran the diagnostics agian and made it all the way to the end where you test the plug at the ECU. That test said to replace the ecu.
So i guess my real question is will a bad ECU make the relay not send power to all that stuff? Anyone got any suggestions about other things I shuold look at or something i may have missed?

[rlux4]

The ECU will not send power to the components, it controls the ground side of the circuits. Things I would recheck: the two ground connections on the left/rear of the intake plenum, the fuse holder connection supplying the dual relay (the brown with white stripe wire behind the fuse panel) and the connection at your temp sensor on the coolant "T". It is possible that the ECU is bad, but it is highly unlikely. Even though the diagnostics point to it as the culprit, I've seen the same results and it wasn't bad. You apparently had the connector off of the back of the ECU, so make very sure the large connector is seated firmly in place (won't start if it's not, don't ask me how I know )
As far as jumping the pink to brown wire, I helped another forum member get his car running with similar issues as yours. His PO had bypassed the brown with white wire and jumpered power to the ECU from the pink wire. It wouldn't work on a regular basis, and once we replaced the feed from the inline fuse to the brown with white wire, it solved his no start issue.
Where are you located? Could be someone is in your area so that you could put in a known good ECU from another car to check that issue.
Ron

[kristoj]

Ron gave you good advice. The CPU rarely goes bad. If your injectors or not getting power, it would most likely be the result of a bad double relay or no power to the double relay (which would be caused by the issues Ron points out). You should definitely replace the inline fuse in the brown wire with white strip.

John

[rlux4]

Ah! Validation, how sweet it is.
I went nuts tracking down why I was occasionally loosing power to the dual relay. The fuse was good, but the fuse holder was at fault. The factory holder whad male/female spade connectors on both ends. I was loosing good contact at the holder. I ended up cutting out the factory holder and replacing it with a regular AGC holder and have not had a problem since.
Put a test light on the dual relay side of the fuse holder by contacting the spade connector, wiggle the holder and see if you are maintaining solid contact.
How are you checking for injector pulse? I didn't have luck with a VOM, so I bought a noid light. It is the ticket for checking signal to the injectors and sensors.
Ron

[BTCTheReaper]

Hello,
Thanks for the feed back. well, i do know the fuse in the inline, as well as the holder is good. i'm putting the jumper from the brown to pink right at the realay, which is after the fuse. The two grounds on the intake have been cleaned, scuffed with sand paper, and checked ok. As far as the temp. sensor, i have tested it's ohm reading at the ecu connector, and it is correct for what the tempature range it was at when tested. For the injectors, i'm using a test light. But i will change out that inline holder just to check, it would be pretty quick and inexpensive check. I'll also double check the connection at the ECU. I just find that it is strange that both relays, the old one ,and the new one, are doing the same thing, usless by some oddball chance i was sent a defective relay.
But anyways thanks again, i give it a try tommarrow, and let ya know what i come up with.

Niles
BTW: i'm in Ypsilanti Michigan

[launieg]

I also have no injectors firing from time to time (other than cold start injector). I have two ECUs and swapping them makes no difference. (I've run with one for a month or two, and now I'm running with the other one, but the problem persists.) When the problem arises, I go through the process of wiggling all the connections, including grounds and relay connections, and eventually it starts again. For a permanent fix, I certainly need to do all the things Ron suggests. So my experience also suggests that your ECU is not the problem, nor is the relay.

[BTCTheReaper]

Hey guys,
well after letting it sit over the winter I got back at it last week. The now power to the brakelights, fuel
gague, radio, and double relay eventually got traced back to a bad on the back of the allernator. The connector
on the black wire that goes to the ignition was broke.
As for the fuel injectors not firing, that was due to the coil not being hooked up properly. I had the pink on
the pos. where it should have been, as well as the borwn/white on the neg. However, i also have a yellow
wire going to the coil, it is in a black plastic sleeve. This wire is not in any wireing diags. After tracing it with a
ohm meter, I determined it needed to be put on the neg. side of the coil. After that she fired right up, however
she did run a little rough, seeing as how this is the first time it stayed running after the rebuild.

But there is still another wire i am unclear of. My coil has a 4th wire that i know attaches to it, but do not know
which side it is suppose to be on, pos. or neg. It is a white wire in a black plastic sleeve. It has 22 printed
down the side of it. Tracing it with a ohm meter, it goes to term. 22 on the ECU connector. This is another
wire that is not in wire diags. In the abriged diagram there is a 22 there, but it shows it as being nothing.

Niles

BTW, thanks for the input from my first posting.

[So Cal Mark]

congrats on solving the issues, and thanks for updating the post. I'll have to look at an FI car to answer about the 22 wire, offhand I don't recall it

[rlux4]

The positive terminal has the pink wire, the black wire from the condenser, and the red wire from the module on it. The negative terminal has the white with black stripe, the black from the module, and a wire in a rubber sleeve (I'm assuming this is the one marked 22 on yours) on it. I didn't trace it, so I don't know yet where this wire in the sleeve to the negative terminal originates. That it would go to the ECU makes sense, as the ECU does make the ground connections for our system. Hope this helps. Great news that you got her running, thanks for the update.
Ron

[Malstief]

I believe my 81 had had the double relay bypassed, as my fuel pump runs at the acc position.
I also have a missing inline fuse and holder for the brown/white wire connectors under the dash, near the fuse box. Finally , I have a green /black wire connector that is running a wire to an unknown source instead of its proper connector . If I hook the green/black up to its proper connector , the fuel pump doesn't run at the acc position. The factor in all this is the car isn't getting fuel to the injectors, but does get spark . Is it possible the bypass was done improperly and I should get an inline fuse holder for the brown /white and connect the green/black together ? Maybe the double relay bypass is causing more problems than solutions ? I've only had this spider for a few weeks , but I've owned a few carbureted versions.