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Help- 1990 Mustang GT

N_rios1

New Member
Hi, new here! I bought my 1990 Ford Mustang GT about 4 months ago and it’s been running great. Recently, I started having an issue. I was on my way from work and the car was fine. Drove from work to my home that’s about 3 miles away without any issues. Once I got home I had to run some errands so I left maybe 5 minutes after I had arrived. Again, the car started and I took off just fine. Maybe about a block down the road, my RPMs dropped pretty low and all of a sudden the car shut off. This was the first time it has ever happened so I was surprised. I tried starting it back up but it wouldn’t start. The car would crank but it would just do that and not actually start up. I tried it multiple times and it just didn’t want to start up and stay on. I had to just push it back home since it wouldn’t start back up. After a couple hours of it sitting there, I tried to start it back up and it did! It also stayed running. I took it around the block and it was feeling fine. So the next day, I started it up and had it running so I can take off. About five minutes of it warming up, it just shut off once again and after trying to start it back up it wouldn’t give. Just cranking again but wouldn’t start up. After I let it sit for about ten minutes, it turned on and stayed on. I’m thinking it might be either a clogged fuel filter or a faulty fuel pump. Anyone have any similar experience that can give me some advice? Thanks in advanced!
 
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broncojunkie

Well-Known Member
Welcome to the group! Sorry, but I'm just now seeing this post. I've been busy at work lately and haven't kept up like I normally do.

Your problem could be fuel or spark. Without going into a long-winded explanation of both, I'll just suggest you narrow that down first. Get you one of those inline spark lights. You just yank a plug wire off and plug it in between the plug and plug wire. Get the car warmed up and when it dies, put the tester on it and see if you're getting a good, consistent spark. If you aren't getting spark, take a look at the ignition coil and the pickup in the distributor. Both are common problems that will show up after the engine heats up.

If you're getting spark, you will probably want to test fuel pressure.
 

N_rios1

New Member
Th
Welcome to the group! Sorry, but I'm just now seeing this post. I've been busy at work lately and haven't kept up like I normally do.

Your problem could be fuel or spark. Without going into a long-winded explanation of both, I'll just suggest you narrow that down first. Get you one of those inline spark lights. You just yank a plug wire off and plug it in between the plug and plug wire. Get the car warmed up and when it dies, put the tester on it and see if you're getting a good, consistent spark. If you aren't getting spark, take a look at the ignition coil and the pickup in the distributor. Both are common problems that will show up after the engine heats up.

If you're getting spark, you will probably want to test fuel pressure.
Thanks for the response! I ended up changing the fuel pump after all and it ended up starting fine. It stayed running for a good while so I took it to the gas station to test drive and top off. I got there fine with no issues but when I left, it turned off again as soon as I was pulling out and wouldn’t start. Same thing, it would crank but wouldn’t start. Luckily, I was only down the street so I had to push it home.

At this moment, the fuel pump works just fine and it starts up just fine. But now the problem is that it won’t stay on unless I’m pressing the throttle. Once I let off, it begins to idle low until it turns off. I thought maybe it was just from it not running for a few days so I stayed on the throttle for a good minute or two and let off to see if it would stay idling but I had no luck. Could it be a timing issue? Idle air control issue? Alternator issue? I don’t know where to start, mainly because of the frustration haha...
 

347HO

Member
Off the top of my head..
I suggest you troubleshoot your ignition, starting with your column.
If you're losing 12vdc to the ignition system, you need to start somewhere. Look for loose pin connections or cut/chaffed wires on the 12v and ground circuits.
If your car has "salt and pepper shaker" connections, those are known to go bad over time.

Good luck.
 

broncojunkie

Well-Known Member
While you're in the column area, check the ignition switch. They're a known problem. In fact, all fox owners should keep a spare on-hand lol! You can check them visually. The housing literally start to separate.

The iac can cause idle problems, but so can a hundred other things. Most common are vacuum leaks or dirty maf. Check your fuel pressure. You could have a pressure regulator going bad. Your alternator idea could be a possibility, too. Definitely test it. However, you'll usually get an alternator light for that one.
 
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