Extended crank issue 3.4l
 

ive searched through threads and cant find exactly what i need:

my 3.4L 4runner has an issue where it long crank starts (cranks a lot before it starts) after atleast 20 minutes sitting from operating temp. if i let it sit overnight or more than 5 hours it starts up as normal, every time. any help? im starting to think it could be a coolant temp sensor if its only after achieving operating temp? it use to be more intermittent but im able to duplicate it almost every day now.

no codes, other symptoms, vehicle runs great no idle issues no bogging no fuel smell no power loss

ive replaced-

OEM STARTER
OEM FUEL PUMP
OEM FUEL FILTER
OEM FUEL PRESSURE REGULATOR
CLEANED IAC
CHECKED BOTH LBJ'S
INJECTOR CLEANER
RED TOP BATTERY

Does 'long' equal more than 5 spins? That's the "standard" for mine yet every once in a while it will fire up on less than 1 spin. :cowboy:

Mine also long cranks- around 5 turns- and I replaced the fuel pump/regulator, did general maintenance (plugs, maf clean, tbody clean etc) to try to resolve it and never made any difference to the concern. Eventually I decided it doesn't seem to be hurting anything and am just going to live with it.

im talking like 10-20 cranks lol

yeah if it was a 5 cranker id be able to live with it too! im shipping my truck from alaska to seattle in january and living in the boonies of idaho skiing. would like to fix the issue while i have my shop and tools before i have nothing :thumb3:

How many seconds on the starter does that equal?

Do you have some injectors dripping and causing a partial flood condition that needs cleared with the long crank when it’s hot?

You can look at inlet air temp and engine temp after the engine sits overnight. They should be the same or within 10 degrees after sitting 8 hours or more.


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Issues only showing up when hot can also indicate a wiring issue. Heat creates extra resistance in the wire and can cause the ECU to not see the voltage signals it needs. Do you have any damaged or pinched wires in the engine bay? Have you cleaned off the grounds and battery terminals with rubbing alcohol?

definitely check your grounds, I used to have an old bronco that would ONLY start after it sat for at least 2 hours. I went around and replaced the old rusty grounds (and starter wires) with thick gauge welding wire and it started right up on the first crank every time.

Where are all the grounds, exactly? I can see the one attached to the plenum on the driver's side, and another one to the firewall on the passenger's.

Yes, there's a block to firewall in the back as well as as the plenum on the driver's side for the diagnostic port (this one gets dirty due to being removed for repairs). There is also your battery ground on the fender which is the most important, this one helps the most. For starting, the lower engine harness that goes from the battery to the starter on the passenger's side has a ground that attaches to the bottom of the block. This one gets real grimy and oily over time and could cause starting issues as well. I think it may be a double ground though since I think it also grounds to the battery cable to fender.

There's also an ECU ground inside the cabin but unless you dunked your 4Runner in a lake this one should be clean.

Great, I'll take a look at those and give'm a clean. Thanks!

We had a similar problem with a high mile 99 Tacoma, never got to the bottom of it. Would fire back up up till about 20 minutes of sitting, after that it would crank and never start, until it sat around an hour. Then it cranks back up like nothing ever happened.

We swapped around everything. Injectors, FPR, fuel filter, plugs, wires, coils, crank and cam sensors, coolant temp sensor, fuel pump relay, swapped the ECU, checked all the grounds on both harnesses, nothing ever fixed or even vaguely improved the symptoms.

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Extended crank issue 3.4l
 

You never swapped the ICM?

On American cars that could be a flood condition from a bad injector or three.

There are only two sensor grounds I’m aware of. They are on the plenum. The ground strap between the head and body just ensures a good engine ground with the chassis. It’s part of the ground from the negative post to fender. You can’t rely on power passing through the engine and trans mounts.


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performed big 3 mod and didnt make difference, checked the block, checked ecu ground even it has never seen deeo water, checked plenum grounds again.

im beginning to think its also an injector issue. it has dealership repair orders from og owner stating they were leaking and performed reseal kit on all injectors