Never starts first time

Jackietaz

New member
01 sport 4.0 rarely if ever starts on the first try but almost always on second. I get misfire codes on random cylinders. My question is should I start with just replacing plugs before looking into coil pack? Is there something else I should look at first?
 

QuicksilverJK

Caught the Bug
Have you tried keying up to run position for a few seconds, then back to off, then start? This would allow the fuel pump to re prime the system before your first start attempt. I am leaning towards possible fuel pump or injector bleeding off.
If that doesn’t work I would have you check for spark on first try, but I’m pretty sure you have the coil rails that sit directly on the plug and I don’t know of a way to verify spark on that one.


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nujeeper

Member
I usually turn the key to the run position for 3- 5 seconds before I crank to start with mine. 2003 4.0
Might be like what Quicksilver is saying - possible fuel pump or injector bleeding off
 
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Jackietaz

New member
Have you tried keying up to run position for a few seconds, then back to off, then start? This would allow the fuel pump to re prime the system before your first start attempt. I am leaning towards possible fuel pump or injector bleeding off.
If that doesn’t work I would have you check for spark on first try, but I’m pretty sure you have the coil rails that sit directly on the plug and I don’t know of a way to verify spark on that one.


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I usually turn the key to the run position for 3- 5 seconds before I crank to start with mine. 2003 4.0
Might be like what Quicksilver is saying - possible fuel pump or injector bleeding off
Thank you for your responses but yes I
have tried both turning the key on and off several times as well as turning key and waiting several seconds before starting. Neither of those make a difference except I learned you can get check engine codes on your odometer. I get a check engine light every few days and it’s usually a misfire on cylinder random #. I have a CE light now I will check it to see.
 

Jackietaz

New member
The CE light is random multiple cylinder misfire detected with pending codes misfire on cylinder 1 & 2. I have OBD II reader and I can gather live data but I not sure which reading I should be watching to get more info if anyone knows that?
 

Strodinator

Caught the Bug
The CE light is random multiple cylinder misfire detected with pending codes misfire on cylinder 1 & 2. I have OBD II reader and I can gather live data but I not sure which reading I should be watching to get more info if anyone knows that?
Start with spark plugs and I'd pick up a quality spark tester as well.

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Jackietaz

New member
I picked up plugs today and my friends shop said they will check out the coil pack sometime next week. I will post solution when I get it figured out. Thanks
 

G-mansjk

Member
Honestly throwing plugs at it might take care of your misfire code and starting issue.. it's the cheapest place to start. No need for testers, pull the fuel relay, take each plug out one at a time and lean it against the block and have someone crank. If you don't see spark than the start looking into other possible issues.

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QuicksilverJK

Caught the Bug
Honestly throwing plugs at it might take care of your misfire code and starting issue.. it's the cheapest place to start. No need for testers, pull the fuel relay, take each plug out one at a time and lean it against the block and have someone crank. If you don't see spark than the start looking into other possible issues.

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Pretty sure this year 4.0 had the coil on plug setup. Basically a rail that bolts down onto the plugs, no wires at all.


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Clifford33

Caught the Bug
Check your battery terminals make sure they are clean from any corrosion. Give it a try see what happens. Mine had problems starting just yesterday and cleaned the terminals and now starts up just fine.


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Jackietaz

New member
Solved

I checked plugs they were pretty new but I changed them then I tested the coil pack and it tested fine. Then I tested fuel pressure and found that when I turn the key on the pressure comes up then immediately falls very quickly so I am thinking fuel pressure regulator is bad
 
They have a bad design. The fuel pump holds pressure, but the check valve weakens over time, especially when cold out, requiring the key to be cycled on and off to prime the system again. 240k on mine and it’s on its second remanned pump for the same reason. The one I pulled out first wasn’t original either.


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Strodinator

Caught the Bug
Honestly throwing plugs at it might take care of your misfire code and starting issue.. it's the cheapest place to start. No need for testers, pull the fuel relay, take each plug out one at a time and lean it against the block and have someone crank. If you don't see spark than the start looking into other possible issues.

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Still doesn't hurt to have a tester lying around that's all 🤷

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G-mansjk

Member
They have a bad design. The fuel pump holds pressure, but the check valve weakens over time, especially when cold out, requiring the key to be cycled on and off to prime the system again. 240k on mine and it’s on its second remanned pump for the same reason. The one I pulled out first wasn’t original either.


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This is most likely it if your loosing fuel pressure right away.

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Strodinator

Caught the Bug
Fuel pump is a very common issue. My sending unit failed idling at the front of a left turn lane on a busy street with barely 110k. That was a fun couple hours. And of course my year didn't have a Schraderi valve so I could test fuel pressure. The Bosch one on Amazon carries a lifetime warranty and it's powering my LS with no issues.

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