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Possible ECM problem

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Old Aug 3, 2013 | 04:15 PM
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Possible ECM problem

So I just bought a 1986 Trans Am, VIN H, so it has the 305 and the CCQJet.

The car will start up and run but has no power and coughs and sputters when I press on the gas. Bought it thinking it was a simple carb rebuild, was unaware of the computer controlled aspect of it.

So I tried to pull the codes to get a start on the problem but jumping the 2 pins on the diagnostic port under the dash does nothing. SES light is on, but it won't even flash the 12 its supposed to.

Where can I start?
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Old Aug 6, 2013 | 10:58 PM
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Re: Possible ECM problem

Bump, help
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Old Aug 7, 2013 | 08:10 PM
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Re: Possible ECM problem

I think no 1-2 flash means that the ALDL to ECM link is in fail mode.

Do you have FSM for the car? You really need it for proper diagnostic sequence...
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Old Aug 8, 2013 | 11:03 AM
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Re: Possible ECM problem

FSM? Not sure what that is.

Its not flashing at all, turn the key and its on solid. There are a few loose connectors under the hood I'm trying to figure out. How much does the ecm actually control on these cars?
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Old Aug 8, 2013 | 01:10 PM
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Re: Possible ECM problem

Originally Posted by Bovaloe
FSM? Not sure what that is.

Its not flashing at all, turn the key and its on solid. There are a few loose connectors under the hood I'm trying to figure out. How much does the ecm actually control on these cars?
ECM controls EVERYTHING, (except air freshener - DTC 99 maybe?)

FSM = Factory Shop Manual. Find one on eBay...
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Old Aug 8, 2013 | 02:06 PM
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Re: Possible ECM problem

Chiltons not good enough? I have one of them. Doesn't have the right wiring diagram, I know that much
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Old Aug 8, 2013 | 03:07 PM
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Re: Possible ECM problem

Originally Posted by Bovaloe
Chiltons not good enough? I have one of them. Doesn't have the right wiring diagram, I know that much
Chilton's ?

Yeah - it's good enough, IF it had a round hollow binding, to hang in the 'Library', where the seat has a BIG hole in the middle.

Tear a page, read, wipe, flush. Repeat if necessary.

'Krinkle', between 'read, and 'wipe', if you're tender in the hindquarters

ed.:
and it's good enough, regardless of your 'style' - front to rear, rear to front, sideways, pinch, blot, swirlie, etc.,

Last edited by Schrade; Aug 8, 2013 at 03:49 PM.
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Old Aug 8, 2013 | 07:19 PM
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Re: Possible ECM problem

Harsh, so before I go dropping $50-$100 on this manual, is it going to have all the right wiring and vacuum diagrams so I can figure out the cluster of wires under the hood?

Is this what I'm looking for?
http://www.ebay.com/itm/1986-Pontiac-Firebird-Factory-Shop-Service-Manual-/151092338350?pt=Motors_Manuals_Literature&hash=item232dce1eae&vxp=mtr
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Old Aug 8, 2013 | 08:29 PM
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Re: Possible ECM problem

Originally Posted by Bovaloe
Harsh, so before I go dropping $50-$100 on this manual, is it going to have all the right wiring and vacuum diagrams so I can figure out the cluster of wires under the hood?

Is this what I'm looking for?
1986 Pontiac Firebird Factory Shop Service Manual | eBay
It is the Bible for your exact car. With it, you can build your car from scratch. Do it to spec, and no one will know the difference between your build, and one from Detroit.
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Old Aug 8, 2013 | 11:48 PM
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Re: Possible ECM problem

Originally Posted by Bovaloe
so before I go dropping $50-$100 on this manual,
Check for a Cd version of the FSM ; cheaper and you can just print out what pages you need and not get the FSM dirty

http://www.ebay.com/itm/1987-Chevrolet-Camaro-Mechanic-Workshop-Service-Repair-Manual-CD-Factory-Guide-/370783160552?pt=Motors_Manuals_Literature&hash=item56546608e8&vxp=mtr
Originally Posted by Bovaloe
is it going to have all the right wiring and vacuum diagrams ,
vac drawing are in the main mech section.
You need to find out if the Electrical component for your year was part of the main FSM or a separate supplement like it was on the later years
Exp

http://www.ebay.com/itm/1987-Camaro-Factory-Service-Manual-Electrical-Supp-/251313885955?pt=Motors_Manuals_Literature&hash=item3a83799303&vxp=mtr
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Old Aug 9, 2013 | 12:28 AM
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Re: Possible ECM problem

FSM is the way to go. Got one for my car today. Other books don't ID relays properly and recycle wiring harness diagrams....I just don't trust them anymore. Not even the torque specs.

PS do some searching for an 88 Firebird service manual here at thirdgen. it is a pdf...about 100mb DL.
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