Engine 1986 gt no start

hawkinsdrag

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Apr 15, 2019
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Need some advice on my 86 gt , 5l speed , no start problem, I have followed the no start check list several times with no luck, have replaced the pump and filter , coil , cap and rotor and wires, and Tfi module, pump primes , good pressure at rails , spark at coil , and plugs , checked power at injectors 12v, did noid light test got good pulse, Tps is good , car turns over good , new battery , cleaned grounds etc. car will start for a second with throttle wide open but dies quickly , I know I must be missing something, bad ecm ?Thanks for any advice
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
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You missed something in the checklist.
Pull the computer and see if there are any burnt traces or a bloated capacitor
Oh, will the computer spit out codes.
 

hawkinsdrag

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Apr 15, 2019
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cant get any codes to flash , can hear the ecm click couple times when I fist turn key on while trying to retrieve any codes, had the ecm out don't see any thing that looks burnt or any capacitors that look any different from the rest., Been over and over the no start list . Thanks for the reply
 

Magnet86

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Jul 21, 2018
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Starter relay? Starter? Inertia switch? How's the main ground at the engine? These were all items I had to deal with recently except the inertia switch. Computer ground or maybe computer relay? Hope it starts for you.
 

jrichker

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Do the last part of the Cranks OK, but No Start Checklist for Fuel Injected 5.0 Mustangs model years 1986-1995...

6.) Spark & fuel pressure OK.
A.) Failed IAB or improperly set base idle (no airflow to start engine). Press the throttle ¼ way down and try to start the car. See the "Surging Idle Checklist for help with all your idle/stall problems.
B.) Failed computer (not very likely)
C.) Engine ignition or cam timing off: only likely if the engine has been worked on recently. If you removed the distributor, there is a good probability that you installed it 180 degrees out of time.
D.) Firing order off: HO & 351 use a different firing order from the non HO engines.

HO & 351W 1-3-7-2-6-5-4-8

Non HO 1-5-4-2-6-3-7-8

E.) No start when hot - Press the throttle to the floor & try starting it, if you get this far. If it starts, replace the ECT.

F. ) Engine that has had the heads off or valves adjusted. Do a compression test to make sure the valves are not adjusted too tight. You should have a minimum of 90 PSI on a cold engine.
 
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hawkinsdrag

New Member
Apr 15, 2019
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Fredericton NB, Canada
only time I get it to start a little bit is with throttle wide open , reset the timing , even thought that maybe some one had changed to non HO engine , tried both firing orders, no change with spout in or removed, 160 lbs cold compression only few lbs difference from highest cyl to lowest , took Iac apart and cleaned , turned key on and the plunger moves. Car has about 200000 km would it be possible it jumped its timing ?
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Ok, go back to the no start checklist and do the ignition tests again, you may find that you missed something or the distributor parts have failed.
 

hawkinsdrag

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Apr 15, 2019
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could the pip sensor still make noid light pulse but still not work properly? getting frustrated , have fire at coil , fire at plugs , checked each one not just number 1 , going to switch ignition switch today to eliminate that, put a new ecm relay in and a new fuel pump relay. next step will be to remove upper plenum to be able to check all the vacuum lines and closer look for any damaged wires
 

hawkinsdrag

New Member
Apr 15, 2019
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Fredericton NB, Canada
I just purchased the car about a week ago, previous owner thought the fuel pump had quit , I tested the pump and it had no pressure, so I replaced the pump and filter, had good pressure after replacing it but wouldn't start. I have checked the firing order , took distributor out and brought it up on compression on number 1 cyl and put it in in proper position , it wasn't wrong to begin with just wanted to be sure. The car is unmolested and all original really don't want to switch to carb but may if I cant figure it out . This isn't my first fox body but becoming the most frustrating one.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
Don't threaten to put a carb on it, more trouble than it's worth and lessons the value of the car.
this ain't rocket science but it does take some dedication.
have you verified fuel pressure?
have you verified spark?
remember simple things trip us up.
if it is cranking over good and not starting with starting fluid it will be a spark issue.
 

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