1990 Mustang Gt Fuel, Spark, no start

StinkySocks

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Nov 20, 2021
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I’m in a little bit of a crossroad and decided to reach out to a forum for help. I recently just finished putting back together my 302 and I am having an issue starting it. Immediately after installing everything back together the motor started up on first crank no issues at all. Then after 4 minutes of running the motor cut off due to a busted fuel line. Since then, I fixed the fuel line, and I can’t seem to get it started. I have good spark and 35 psi of fuel, and the motor will just turn over occasionally sounding like it wants to start but won’t. I pulled the spark plugs and noticed that some of the plugs are wet with fuel while the others are dry. I would greatly appreciate some help as I don’t know where else to go beside just pulling the motor apart once again.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Back to basics, pull the plugs and crank it a few times to dry out the cylinders, clean the plugs (they are new right?) I'd spray a touch of starting fluid in the throat and if it don't start There is a checklist that will help:
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
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Hold the gas pedal to the floor while cranking. Be ready to release when/if it starts. This act puts the ECU in “flood clear” mode which does t allow the injectors to add more fuel.

After you get it started, check your timing. I’m guessing it’s a bit retarded
 
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StinkySocks

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Yeah I ended up putting starter fluid on the spark plugs and it still wouldn't start. So I ended up pulling out my ecm and notice that two of the capacitors were burned up and barely hanging on. I'm gonna take it to a shop to repair the Ecm and hopefully this resolves my issue. Thank you guys for the help.
 

StinkySocks

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Hey, just thought I give an update. I ended up getting the Ecm yesterday and plugged it back in, on first crank the car fired right up no issues. I let the car sit for a while and after two hours I went to start the car and it didn't seem like it wants to start. I tried to spray starter fluid and opening the throttle body all the way but the motor just keeps turning over. I'm back at cross road where I don't know where to go. I'm getting 40psi to the fuel rail and I'm getting a good spark as well. I would greatly appreciate some insight as to anything else I can check for.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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Were you able to set your base timing during the period it was running? Did you attempt to start it in flood clear mode?
 

StinkySocks

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Yeah I attempted to start it in flood clear mode and nothing it didn't even sound like it wanted to turn on just keeps turning over. The timing more or less was completely off as it backfired a couple times but it would start on first crank.
 

StinkySocks

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I tried to spray each spark plug with starter fluid and still nothing. I've read that checklist multiple times already and gone through checking everything and it still seems like it doesn't want to start.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
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Then start over with the basics.
If you did the checklist per instructions then you missed something. It's usually something simple, air, fuel, spark. If it will not start by spraying starting fluid in the intake then it is a spark issue. You don't spray the plugs. If it starts with the spray it's a fuel delivery issue, this is if the timing has not been messed with, if the distributor has been moved or removed start with re-timing it, pull the #1 plug, turn the engine over till the pointer on the crank is at 0*. Verify the #1 piston it at TDC by sticking something in the spark plug hole, you should feel the piston top, mark the #1 plug wire on the side of the distributor, rotor should point to the #1 plug wire mark. This is your starting point, now you need a timing light to set it at 10* BTDC. You may have to clean and mark the balancer with a white marker at 0* and 10*. What I do is paint the timing marks from 0* to the end of the marks in white paint then with a sharp pointed tool I scratch the line at 0*, 10*, 12*, 14* my engine liked 13*,
 
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Boostedpimp

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I'd pull the ECM again and make sure you didn't fry it... If you did then I would look at the oxygen sensor wiring to verify it is correct before repairing the ECM a second time.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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Agreed.

Test continutiy from pin 46 to both pin 40 and 60. You should have it in all combinations.

Has anything changes wiring wise on the vehicle? It ran before correct?
 

StinkySocks

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Nov 20, 2021
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So I ended up doing the timing again and spraying starter fluid and still nothing. Then I pulled the computer out and gave it a look over and tested pin 46 with both 40 and 60 for continuity and it was fine. The wiring harness as far as I know is completely original on the car. Only thing that seems to be done was a kill switch and a prestige aps 2 alarm system which I believe is aftermarket. The kill switch doesn't seem to working at all, it almost seems as something electrical is holding back the motor from starting. I got great fuel, great spark and timing is set to top dead center. I don't know what else it could possibly be at this point the motor ran perfect yesterday morning. Would greatly appreciate some feedback as to anything else I could possibly test.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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A kill switch and aftermarket alarm would have been nice to know bout in the beginning.
If you have spark, fuel it should at least try to run.
 

StinkySocks

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Yeah sorry about not mentioning that. The previous owner had it installed but he was uncertain if it worked properly. It seems like something electrical is holding back the motor from starting. I'm Just gonna have to pull off the dash and check the wiring.