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Discussion Starter · #1 ·
As I mentioned before, I do have an occasional (but more often than not) slow starting phenomenon.

Starting takes several seconds. If I ever get so impatient that I abort the engine start, then immediately try again, the engine starts instantly.

This has led me to believe that the fuel is running back into the tank. I understand there is a check valve in the fuel pump; however, I'm not really interested in lowering the tank at this point.
Therefore my question: has anyone ever placed an additional check valve into the fuel line and if so, where exactly?

I also understand that there may be another cause entirely to this. Leaky injector maybe.
Also, if fuel runs back into the tank, does that mean air is somehow getting into the fuel line, or is the fuel just expanding back into the tank because it was under pressure in the fuel line while the engine was last running?

This is not a huge concern; the engine always starts. It's just a bit tedious, plus I'm wondering about wear on the starter.
 

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1997 Thunderbird LX
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How often are you driving the car, every day? If the gas is running back to the tank I'm not sure how long that would take. Even if mine has been sitting for some time, I turn the key to on and listen for the fuel pump to come on then give it a couple of seconds then start it. Knock on wood but I haven't had any issues.

Joe
 

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1994 Cougar XR7 DOHC/5-Speed
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The main purpose of the in tank check valve as is to prevent fuel in the tank from rushing up the return line in the event of a rollover accident and leaking out of a severed line. When you start the car the fuel pump pressurizes the pressure line up to the regulator, it takes some time for the pressure to bleed off on its own, even with the car off for a day there’s still some pressure in the rails, it can’t backflow to the tank.

I’d look into other issues, possibly a bad fuel pump or something else causing the hard starts
 

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It is a bad fuel pump check valve. Very common on these cars. Either turn the key on for two seconds before continuing to the start position, or replace the fuel pump.

I choose the former on my current T-Bird. I eventually chose the latter on my old T-Bird, though it wasn't a 100% fix, a new fuel pump was about 90% successful for quick starts.

They start right up if you wait two seconds. It also bleeds down in under an hour, so I do the same procedure all the time.

Al
 

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1997 Thunderbird LX Sport
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Way back in 1999 I hopped in my '95 T Bird and did a quick start and I got nothing. Wound up being the PCM which was a fortune for me at the time. So since then, in every car/van/truck I have had, I always turn the key to power everything...wait.... then crank. Not sure if my PCM problem could have been negated by a slow start but I have always wondered. Another thing is to turn off the a/c/ heater before turning the car off. But it does help to get power/gas to everything before cranking.

That said, if it is hard to start there is some issue with getting gas or spark. The fuel pump check valve is a likely suspect. I recall you changed your fuel filter and that helped then, but have you done a spark plug wires/ plugs tune up yet? Also might want to see if the car is throwing any codes. If the slow start works, that should help narrow the cause down to a fuel issue.
 

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Discussion Starter · #8 ·
I recall you changed your fuel filter and that helped then, but have you done a spark plug wires/ plugs tune up yet? Also might want to see if the car is throwing any codes. If the slow start works, that should help narrow the cause down to a fuel issue.
Maybe the fuel filter gave me a bit of a placebo effect. I did initially feel there was an improvement, but no...

No, I haven't done spark plugs at all. I understand they're pretty cheap though, correct? How easy are they to change?
Wires? That sounds expensive, plus mine say "Wired for Life" on them; I'm taking that literally.

I actually don't own a code reader; I'd have to go to an auto shop to tell you. There's no check engine light though.
 

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Discussion Starter · #9 ·
@T6Rocket, @GreenT, I have to say I always wait for the fuel pump prime sound to subside before I crank. I may not specifically wait though after the sound subsided. We're really talking seconds here.
Next time I'll count to 5 before cranking to see if that makes a difference.
 

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The fuel pump runs for only 2 seconds when you turn the key on, you can hear it. No point in waiting longer than that. Don't have to turn the A/C or anything off either.

It's not going to be spark related. You either have spark or you don't, there is not going to be a delay.

Al
 
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1997 Thunderbird LX
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Plugs aren't too tough on the V6, a little tight on the passenger side though.

Joe
 
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Mine will do the same thing after sitting for a day or two. Need to wait a second or two for the fuel pressure to build up. If the ignition is cycled twice it will start up instantly. I plan to replace the pump eventually as it's the OEM as far as I can tell. I'll go ahead and cut an access hole and post pictures to trigger a few folks here. :ROFLMAO:

The old 96 Tbird V8 I used to own had the pump replaced at some point before I bought it. It never had this issue and would start up right away if it sat for a week.

Also the ECM went bad in my Cougar years ago. It completely crapped out on me one day at a very bad time and I ended up having my Cougar flat bedded back home. After replacing the ECM I noticed it would start noticeably faster. So that was a separate unrelated issue.

Not saying your ECM is bad, but if it takes long to start even with the fuel pressure is built up, something isn't right with it.
 

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I have the same issue going on with mine. I replaced the injectors for other reasons, it does start up better now. Many times I would have to prime twice to get her to start.
When I cleaned and tested the old injectors I did have 1 leak, so probably a contributing factor.
 

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Discussion Starter · #17 ·
Here is a normal start. The car hadn't been driven for a little over an hour; it's still warm-ish.

This is how long it usually takes; occasionally it takes longer. This is with a single prime of the fuel pump.

On a side note, is it normal that the airbag light comes on twice: once when you turn on the ignition and again when you start the engine?

[Please do not comment on YouTube. I don't really use it and would likely miss your comment.]

 

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Maybe it's me, I don't think it's that bad.:unsure:

Joe
 

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Discussion Starter · #19 ·
Maybe it's me, I don't think it's that bad.:unsure:
Sometimes it takes longer. But I hear you; it could be worse. Maybe I'm spoiled from driving brand-new cars for the last twelve years; and I honestly don't remember how my Crown Vic and Continental behaved (I owned those over twelve years ago).

I have been known to have some slight automotive hypochondria, too 🤒
 
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