Georgia Fiero Club Forum
All Things Fiero => Tech Tips, Tech Questions => Topic started by: Donster on April 30, 2011, 01:37:05 am
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It's getting weird now.
Last week the radio would cut off if I tapped the brakes - then the symptom disappeared.
Now, the engine will start - but - No lights, except turn signals, no radio, no dome light, no running lights, no emergency flashers
Checked all fuses. Could this be a relay? Is there a relay that controls all above mentioned?
????
Did I mention ????
Help!
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Have you checked your fusible links?
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Link B is good
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Here's a link where you can download the 84 Factory Service Manual. While you're there, download the 86 manual. It pretty much covers all years even though it's for an 86.
http://www.fieronews.net/fusion/downloads.php
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Thanks Charlie, but I already downloaded them ALL a while back.
And I noticed that only the 84 FSM has the correct layout for the fusible links. Haynes lists the fusible links as connected to the battery junction box, which was not used until 85 and later ;)
Found my culprit: One of the BOSCH relays on the left side of the firewall - $ 4.59 @ O'Reilly's
She's illuminated with sound again ;D
Thanks all
\D
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new symptom - no fuel to the TBI, pump is running
The electrical gremlin is crawling everywhere in this car it seems
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OK, shorted pin G on the ADLC - pump runs
When I turn on ignition, fuel pump relay clicks, but only once instead of twice and I don't hear the pump
Is that the symptom of a bad pump relay? Swapped it with the A/C relay, which is identical, but it doesn't even click - not using A/C so I have no way of confirming if it is good or not.
So my actual question: If I short pin G and the pump runs, but the relay doesn't get it to run while not hotwired - is it the pump or the relay??
??
\D
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It would be the relay or the circuit between the relay and pump. If it was the pump, it wouldn't run, whether hotwired or not.
If you cycle the ignition too quickly, the relay or pump won't activate because the fuel system is still up to the required pressure. The pump only runs for .8 to 2 seconds or until the fuel system reaches required pressure, whichever comes first.
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Just put in brand new relay - same result - it clicks once - don't hear the pump - no fuel to TBI
I always paused between turning on ignition/cranking - figured that one out ;D
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I do, too so the system can pressurize and the car will start quicker. What I meant was that if you cycle between the OFF-RUN-OFF-RUN too quickly, and there's no leakdown on the fuel system, the relay or pump won't activate. Do you still get the same result when you leave the ignition off for 15-20 seconds before turning it back to RUN? It could be that the harness between the relay and pump is disconnected. Ashby wasn't able to help you when you talked?
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same result even with pause
Ashby and I haven't talked yet
\D
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OK, jumped pin B (green) on the relay and hear the pump run
with ignition on I get power to the green wire on the injector (solid)
While cranking nothing on the orange wire
Does this sound like a bad circuit on the ECM, as obviously relay, fuses and pump are ok?
HELP!
Did I mention: HELP! ?
\D
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From my wiring charts, the green wire should be on pin B. Pin A would be the Tan/White wire and when given power would be the same result as jumping Pin G of the ADLC. I will assume you named the pin wrong and we are actually referring to the green wire.
The green wire is the input from the ECU. It connects to pin 18 of the red/white connector. If it works when putting 12v to the green wire, then it is either a broken wire to the ECU or it is the ECU. I would first check voltage on pin 18 and see if you get anything (key on, of course), that should tell us if the ECU is good or not.
Is this an auto or a manual? If it is a manual, I have an 84 manual ECU that worked last time I drove the car (though it has been a few years) that I could drop in the mail to you.
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4 speed manual
Yes, I was referring to the green wire, which when +12V applied, fires up the pump
You say: "It connects to pin 18 of the red/white connector." ???
You also say: "I would first check voltage on pin 18 and see if you get anything (key on, of course), that should tell us if the ECU is good or not." Again ???
Where do I find pin 18?
If it is the ECU and you get yours to me, you just became my best friend ;D
Kidding asside, if I know where pin 18 is, I'll test it and let you know
\D
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Correction:
The pump fires up when applying +12V to the TAN/WHITE on the FP Relay connector
+12V to Green does nothing - my mistake
Does this give anybody another idea or should I still assume it's the ECM or at least the connection between the FP Relay connector and the ECM?
Anyone?
\D
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Don, I don't know your wiring on the Iron Duke, but when my V6 quit running it turned out to be the power wire from the ECM under the center counsel at the connection between the seats about 4 inches from the connector, you could not see a break in the wire until i started probing it with a straight pin, spliced in new wire and WALA, that was about 7 months ago and no problem since
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kewl, now can you also tell me which one is the power wire? ;D
\D
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No "Check Engine" light. Is that of importance??
\D
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It's back to the "No radio, no lights, no dome light, no emergency flasher" plus no fuel coming out of the injector!
I am suspecting a major foul-up in the electrical system or bad ECM but don't know how to confirm a bad ECM.
on the FP connector I get no +12 V on green or tan/white when turning on the ignition to prime the pump. I know it should send power for about 2-3 seconds. The orange however does have power.
I am getting too confused now. I have taken notes on everything I have tried so I don't back-track unnecessarily but am stuck and giving up hope.
I could really use some guidance here. How can I confirm a bad ECM. Various posts on other forums haven't helped
\D
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This just keeps getting better ............
....now the battery is getting hot! Just from setting there!
??? ??? ???
\D
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Disconnect the battery NOW!!!
Pour water on it to cool it down ASAP!
Do not attempt to get too close to it. It will be releasing a lot of explosive gas now.
You can try to search for the obvious electrical short after it cools. Much later.
Possibly the alternator....but later.
Disconnect now!
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The Don
What up? You still here? Hope so! A hot battery is no fun. Seen 'em blow up...not pretty.
Seen people that were near when they blew up...not pretty.
If there is no electrical short in the system, built up sulphates in the battery can short out cells.
If enough of them short together the battery will self destruct.
There is no fix. Just get a new battery.
Much better, cheaper and easier than getting a new The Don!
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might have been too late disconnecting the battery, now nothing is working anymore - she's dead - and most likely going to stay dead until I get the new ECM in the mail and maybe somebody to help me figure out where she has wires crossed
\D
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I was thinking it might be a fusible link that has failed based on your initial symptoms. Now, it sounds like something is shorted out. Try disconnecting the cooling fan connector at the motor. If the cooling fan shorts out and blows a fusible link, the electrical system will go haywire.
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I'll try it when I get home
Connector at the "Fan Motor"?
\D
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The harness plugs into the cooling fan motor. When my 87 had the same symptoms, the cooling fan motor shorted, blowing a fusible link and the car shut down. Only thing that worked was the interior lights.
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right now, they don't even work
do you remember which fusible link it was that blew?
\D
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I'm glad you're alright.
You sure know how to startle the fertilizer out of somebody.
There's a link somewhere on this site that has ~all the factory
manuals. Fierofool probably knows right off the top of his head.
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The fusible link on mine was located at the junction block near the battery. The 84 is located on the back of the cockpit, and the wiring is different on the 84's. There's also one down near the starter. If it is a fusible link, then you've got something that's grounded out pretty good. I'm not much with electric problems is why I've not made many suggestions. I don't want to get you off on the wrong track.
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I'm glad you're alright.
You sure know how to startle the fertilizer out of somebody.
;D
Thnx, fertilizer bering the operative word, found some of that in my britches afterwards
\D
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I'm not much with electric problems is why I've not made many suggestions. I don't want to get you off on the wrong track.
Neither am I and I've already been on so many tracks, it's pathetic. Everythime I check one thing, another symptom pops up
\D
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OK, I'm at the point where I'll pay whomever howevermuch to come here and do whatever to fix it!
Anybody?
\D
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don why don't you let that thing go , aerodonamic has a pretty nice 87gt for sale for $1600.00 obo, lots of new parts.
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it's not mine to let go, it's Anne's and we are about $3k into it
Don't think it would go over well with her ;D
\D
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oops!!!
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don did aerodonamic send you a message, i was at his house tues or weds and he had a black plastic/rubber air dam. i told him you were looking for one but i can't what car it came from.
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don did aerodonamic send you a message, i was at his house tues or weds and he had a black plastic/rubber air dam. i told him you were looking for one but i can't what car it came from.
Nope
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OK, I'm at the point where I'll pay whomever howevermuch to come here and do whatever to fix it!
Anybody?
\D
The offer still stands!
I'll pay top dollar!
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well you two would have to talk and decide if its the right one.
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Don, send 88_4mula an email. He's pretty busy right now, but he's good at tracing and troubleshooting electrics.
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Don, send 88_4mula an email. He's pretty busy right now, but he's good at tracing and troubleshooting electrics.
Done, haven't heard back.
\D
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well you two would have to talk and decide if its the right one.
Sent email and PM, no word back
\D
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From my wiring charts, the green wire should be on pin B. Pin A would be the Tan/White wire and when given power would be the same result as jumping Pin G of the ADLC. I will assume you named the pin wrong and we are actually referring to the green wire.
The green wire is the input from the ECU. It connects to pin 18 of the red/white connector. If it works when putting 12v to the green wire, then it is either a broken wire to the ECU or it is the ECU. I would first check voltage on pin 18 and see if you get anything (key on, of course), that should tell us if the ECU is good or not.
Is this an auto or a manual? If it is a manual, I have an 84 manual ECU that worked last time I drove the car (though it has been a few years) that I could drop in the mail to you.
CowsPatoot is officially my best friend now! ;D
Enough said
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If you need a 84 ECM, I have one you can have...Just have to find it.
I took all the electronics off the 84 before scrapping it for metal.
Let me know if you need it.
As far as the problem goes.
If you have a bad ground power will back up through things like relays and bulbs trying to find a ground source.
I would start with the grounds that will cause all kinds of havoc, are under the dash near the column.
Others are under the center console near the ECM.
Check the ground in the engine compartment near the battery.
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Thnx, email sent
\D