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Discussion Starter #1
This issue does not search well due to common terms...

07 FJ 65k miles with random hard start issue. No rhyme or reason. Just have to give it a little gas to get it to kick over sometimes. Anyone heard of this? No codes and due to the random nature, I have no clue. Anyone have any ideas? I'm a mechanic and this one has me baffled.
 

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Is it the original battery. If yes buy a new one or load test the one in it. Check batt connections for corrosion/looseness.
 

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You should not have to touch the gas to start the FJ. Something is up and needs fixed. As mentioned above ^^^^^^ this is a great start.
 

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Discussion Starter #4
Starter always spins the engine like a top... It's almost like a dry start. A little throttle and its good to go. Quite aggravating. Especially since it does not matter if it's hot or cold. Very random. First thing I did was clean the MAF as I've seen that make a difference with the Evo rally cars I make a living off of. However no dice. I'll try plugs next as admittantly, I've not taken the time to look at them. Bought th truck with 62k already on it.
 

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Fuel filter getting plugged? Does the fuel pump just fail completely? Or would the intermittent no start be a sign of impending fuel pump failure?
 

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If the air filter & MAF are clean, and the plugs are in good shape. I'd check for an intake air leak and check your static fuel pressure.

DEWFPO
 

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Discussion Starter #8 (Edited)
Oh, TRD intake too.

Though about fuel pressure right off. Fried my FP gauge and need to replace it... Good excuse as any to get another. However, mainly looking to see if anyone's had similar issues for a particular reason.

Thanks for the input guys...
 

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I have the same year fj. Also have around 62,000 miles on mine. I have the same problem, just once and awhile it does this. I have the airaid intake on mine and figured it was time for plugs. Curious how this turns out!
 

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Discussion Starter #10
Well, the issue went away on its own last February (I know, I know) so I forgot about properly diagnosing it... until now. It's back and I guess I need to buckle down and do something about it this time.
 

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did you ever figure this out? mine just turned 50k miles and started doing this. will crank really strong for a few seconds before starting. just replaced fuel pump with the URD in tank pump and all plugs look perfect also.
brand new odyssey pc2150 battery.
no codes.
know my way around an engine pretty well and this one has me baffled as well.
 

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I've had this happen for awhile now too. Very random and it did it both before and after new plugs and everything. Battery is good too. Really strange.
 

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Just to re-surface this thread, since my '08 did this no-start thing this morning for the first time. She always, and I mean always, starts right up after maybe 4 revolutions (call it about 1.5 seconds or less of cranking). No matter the ambient temperature, very very dependable.

This morning, I cranked for about 3 or 4 seconds....she kinda wanted to cough....so I got off the key and cranked again for about 3-4 seconds and she finally reluctantly stumbled to life, then settled into a normal strong idle.

This is not normal, there has to be a reason for something to happen just out of the blue. Of all the threads and comments I've read, nothing yet points conclusively to the culprit. We'll see what she does today when I light her up after work.
 

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Just to re-surface this thread, since my '08 did this no-start thing this morning for the first time. She always, and I mean always, starts right up after maybe 4 revolutions (call it about 1.5 seconds or less of cranking). No matter the ambient temperature, very very dependable.

This morning, I cranked for about 3 or 4 seconds....she kinda wanted to cough....so I got off the key and cranked again for about 3-4 seconds and she finally reluctantly stumbled to life, then settled into a normal strong idle.

This is not normal, there has to be a reason for something to happen just out of the blue. Of all the threads and comments I've read, nothing yet points conclusively to the culprit. We'll see what she does today when I light her up after work.
Do the easy stuff first....
plugs
MAF (get that spray right in there)
throttle body

Then see where you're at...
:cheers:
 

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Just to re-surface this thread, since my '08 did this no-start thing this morning for the first time. She always, and I mean always, starts right up after maybe 4 revolutions (call it about 1.5 seconds or less of cranking). No matter the ambient temperature, very very dependable.

This is not normal, there has to be a reason for something to happen just out of the blue. Of all the threads and comments I've read, nothing yet points conclusively to the culprit. We'll see what she does today when I This morning, I cranked for about 3 or 4 seconds....she kinda wanted to cough....so I got off the key and cranked again for about 3-4 seconds and she finally reluctantly stumbled to life, then settled into a normal strong idle.

light her up after work.
OK, this is the first post with any really useful diagnostic info.

"This morning, I cranked for about 3 or 4 seconds....she kinda wanted to cough....so I got off the key and cranked again for about 3-4 seconds and she finally reluctantly stumbled to life, then settled into a normal strong idle."

The " ...reluctantly stumbled to life, then settled into a normal strong idle" is critical.

1. How many miles on the engine?
2. How long had the vehicle sat since the last shutdown?
2. How long did it "stumble" before running clean?
3. Was there any raw fuel odor from the exhaust (may need an observer/sniffer at the tailpipe for the next several cold starts).
4. Do you run primarily "top tier" gasoline?
5. Do you ever run fuel injector cleaner through the fuel system?
6. For the others experiencing this problem, does the engine typically "stumble" for a few seconds after it first fires, or once it fires does it instantly run smoothly?

The "stumbles" for a few seconds after firing can be a symptom of leaking fuel injectors. The leaking injectors can do two things:

1. Slowly bleed out the residual pressure that's in the fuel supply lines to the injectors. Then, the fuel injectors don't start spraying the instant the engine starts cranking; they've "lost their prime". The fuel pump only starts up during cranking, and it can take a second or two to build full pressure at the injectors, leading to a delay in firing.

2. In a severe case of multiple injectors leaking, they can "load up" the intake manifold with a few CC's of raw fuel during shutdown. During the first few seconds of cranking, the mixture is too rich to ignite, but after a few piston strokes enough air has been pulled through to sweep out raw fuel, and finally the engine fires but runs roughly. After another second or two the mixture is back to normal, and the engine runs smoothly.

You can connect a fuel pressure gage into the fuel supply system to check for "bleed-down" while the engine is shut down, but this takes a special adapter to connect into the fuel line.
 

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i've had this problem once or twice on separate fj's, on mine it was after i bought cheap gas. Try buying some sea-foam or octane boost
 

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OK, this is the first post with any really useful diagnostic info

1. How many miles on the engine? 50,000
2. How long had the vehicle sat since the last shutdown? 14 hours
2. How long did it "stumble" before running clean? about 3 seconds
3. Was there any raw fuel odor from the exhaust (may need an observer/sniffer at the tailpipe for the next several cold starts). none
4. Do you run primarily "top tier" gasoline? nope, 89 octane, same source as always.
5. Do you ever run fuel injector cleaner through the fuel system? haven't yet
6. For the others experiencing this problem, does the engine typically "stumble" for a few seconds after it first fires, or once it fires does it instantly run smoothly?.
Will buy a can of MAF sensor cleaner and try that out too. This morning, she started like a dream.
 

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Will buy a can of MAF sensor cleaner and try that out too. This morning, she started like a dream.
Dirty MAF sensor or fouled spark plugs are unlikely to cause "intermittent" hard start condition with short-term "stumbling". Whatever effect they have on starting would be more or less constant at every cold start.

The key here is the stumbling immediately after start; got to find out what the root cause of the stumbling is, especially if it is intermittent.
 
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