1989 GT cranks but won't start

Vince305

Member
Sep 25, 2021
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Fuel pump or TFI module
Check fuel pressure
Check blinking light on negative side of the coil while it cranks over
Noid light on injector (look it up if needed) just a light to blink showing the processor is trying to fire the injector
Did your mechanic do the checklist?
So, I finally was able to have someone else come out and check it out. It was able to run on starting fluid, and since the fuel filter had already been replaced it's the fuel pump. The car had sat for atleast 25+ years, so whatever junk in the tank has clogged the fuel pump.

With that being said the only way to replace the fuel pump is to drop the fuel tank correct?
 

Rdub6

So while I wait to figure out my rear end issues
Dec 29, 2017
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So, I finally was able to have someone else come out and check it out. It was able to run on starting fluid, and since the fuel filter had already been replaced it's the fuel pump. The car had sat for atleast 25+ years, so whatever junk in the tank has clogged the fuel pump.

With that being said the only way to replace the fuel pump is to drop the fuel tank correct?
Didn’t you say you had fuel spraying at the rail?
 

Vince305

Member
Sep 25, 2021
19
3
13
Didn’t you say you had fuel spraying at the rail?

Yes, but because the fuel pump is clogged I think it was only getting a little bit and then sometimes not even any at all. Like when we were cranking it would fire once or twice but stumble because it wasn't getting a flow of fuel. When we had been spraying starting fluid it would run continuously, no stumble.
Another twenty five year old gas situation. Read up on it here so you get the gas out. Then you should get it right
That's not the entire case, It has been my daily driver for the last 2 years but due to it sitting for 25+ years the sediment/gunk finally clogged the fuel pump (Which I kind of expected, and figured it might be the cause to why it's not starting). Also I'm either gonna have the fuel tank cleaned out or replaced while the fuel pump is being replaced.
 

rednotch

Founding Member
Aug 14, 2000
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So, I finally was able to have someone else come out and check it out. It was able to run on starting fluid, and since the fuel filter had already been replaced it's the fuel pump. The car had sat for atleast 25+ years, so whatever junk in the tank has clogged the fuel pump.

With that being said the only way to replace the fuel pump is to drop the fuel tank correct?
Yes it needs to be dropped its not hard, can do it in 2 hours with hand tools if need be. if it sat that long buy new pump, tank and a can of kooler clean, new tanks like $100 if you shop around, pump depends on what ya want but even a 340lph is less then a bill these days. Your going to need air to blow out the fuel lines and rails, the tanks going to be junk from the old fuel pulling water and rotting if it really sat that long, it will just kill a new pump if its got rot inside. kooler clean is meant to flush transmission lines but will work for the fuel line too, disconnect it at the rail and the filter run a can threw it at rail side and the lines from the filter to the tank then blow it out with air from the rail side.. After that put it back together.
 
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Vince305

Member
Sep 25, 2021
19
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Yes it needs to be dropped its not hard, can do it in 2 hours with hand tools if need be. if it sat that long buy new pump, tank and a can of kooler clean, new tanks like $100 if you shop around, pump depends on what ya want but even a 340lph is less then a bill these days. Your going to need air to blow out the fuel lines and rails, the tanks going to be junk from the old fuel pulling water and rotting if it really sat that long, it will just kill a new pump if its got rot inside. kooler clean is meant to flush transmission lines but will work for the fuel line too, disconnect it at the rail and the filter run a can threw it at rail side and the lines from the filter to the tank then blow it out with air from the rail side.. After that put it back together.

Thanks for the info, I'll definitely keep all that in mind. Going to have it all worked on in the upcoming weeks and I'll definitely let you know how it goes! Thanks again for the info and tips!
 

Vince305

Member
Sep 25, 2021
19
3
13
Well, finally got the problem fixed and car running like the champs. Ended up finding a guy who specializes in working on Ford Mustangs of all years. So, the problem I had originally may of been like a TFI Module or something real small but one of the two mobile mechanics I had work on it jumper cabled the battery backwards and fried the entire ecu, and other electronic parts. Of course whichever one did it didn't bother to say anything about it.

Anywho, I had all the electronic stuff done, timing and idle adjusted, new 3G Alternator put in, and now it runs perfect. I had the battery tested twice just to be sure that it's fine, and it came back as 100% with no dead cells or any issues. So, I will definitely not be using any mobile mechanics ever again, and just going to this mechanic who specializes in the Foxbody Mustangs that knows what he's doing. Ya live, and ya learn, and I definitely learned this time around. I also very much appreciate all the replies and help I received on this forum post! Thanks again - Vince
 
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jrichker

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I'm the guy who wrote the checklist, and I have been driving and fixing pushrod 5.0 EFI Mustangs since 1991.
Do the checklist, you don't have to be a mechanic to understand it and make it work for you.
 
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Vince305

Member
Sep 25, 2021
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I'm the guy who wrote the checklist, and I have been driving and fixing pushrod 5.0 EFI Mustangs since 1991.
Do the checklist, you don't have to be a mechanic to understand it and make it work for you.
Oh I appreciate it, and that's a great list that like you said works! Unfortunately, it probably would have worked for me at the start when I had the problem but one of those whack mobile mechanics jumper cabled the car backwards and whatever else to fry some of the electronics. I ended up just taking it to a certified mechanic that works on these years of Mustangs and he fixed it all up, runs like a champ now. So the problem is solved and fixed now. Not sure if there is a way to mark this forum/post as solved to let others know it's been fixed/solved? I appreciate it though!