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Doug
Doug, ASE Certified Technician
Category: Toyota
Satisfied Customers: 8538
Experience:  Toyota Expert Certified through 2007
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2005 Toyota 4Runner 4.7L V8 crank start issue - its going to

Customer Question

2005 Toyota 4Runner 4.7L V8 long crank start issue - its going to be hard to test during a hard start because I do not know when it will occur, I am usually running out the door to work or whatever and it does not do it twice in a row. It seems to be totally random.
Submitted: 10 months ago.
Category: Toyota
Expert:  Doug replied 10 months ago.

Hi,
This is going to be a real bugger to test outside of fuel pressure. At least with fuel pressure you could leave a gauge hooked up and laying on the windshield etc.
Do you have any sort of scan/obd tool that shows data? Perhaps we could have that hooked up as well and watch RPM signal to see if it is at zero when the problem occurs (Crank sensor malfunction)?

Customer: replied 10 months ago.
I bought one of those little orange Actron devices that stay plugged into to OBDII port as you drive and read out on the iPhone app. Not ready TS yet - no rush - just clicked on Rush to get you the max payment! You don't have to respond unless you want to dictate my first steps today!
Customer: replied 10 months ago.
I also have a cheap handheld Actron tester
Expert:  Doug replied 10 months ago.

No problem at all.

Lets make sure that thing can read engine RPM specifically as that is a big suspect. If you have a reading for circuit opening relay (probably not... thats something you usually only see on the Toyota scan tool) we woudl want to monitor that too. Then we wait.... when it happens again hopefully we see something (zero or erratic engine RPM, c/open relay saying "off" etc).

Customer: replied 10 months ago.
I wanted to show you what all parameters that I can track with my U-Scan OBDII device. I took screen shots of 5 of the pages of data that it will read out via blue tooth on my cel phone. It is starting to take so many cranks sometimes now that it gives you the feeling that it may not start - like 5 to 7 "cranks" if that makes sense. I notice that the RPM via the tach is always VERY steady even when it is idling a little rough from the cylinder issue I suppose. The U-Scan app DOES show RPM. I tried it on a few starts and it shows "0" RPM with the key on and they reflects an increasing RPM as it starts. It showed 114 RPM as it cranked but it was not doing the hard start thing when I tried it either. I read the codes today and there is an additional C1201 Engine Control System Malfunction Code but I think you said months ago that is normal to accompany the P0306 Code. Take a look at these added files of the screen shots of my cell phone and the readouts it is capable of. I can leave the U-Scan device plugged into the OBDII port and try to have the app fired up every time I start from now on and watch the RPM or whatever else you think would be useful in this app. It is very gradually getting worse starting from last summer.
Expert:  Doug replied 10 months ago.

Yeah the C code should be just there to turn the trac light on when there is a engine drivability fault.
Lets watch that RPM value when the hard starting occurs and see if there is anything noteworthy there (like suddenly showing zero of course, or erratic reading). The 114 is actually a bit low, normally we see 200-240. It is still acceptable if it is steady though and engine is starting normally.
Nothing else is too terribly interesting there.... perhaps watch the IAT and coolant temp too just in case. Either will cause sudden over fueling if reading out of spec, but I've honestly never seen either fail on a 4Runner before.

Expert:  Doug replied 10 months ago.

Not to mention neither would just suddenly cause it to go back to normal while cranking either. That is more like a crank sensor, or fuel related like we discussed before (building up pressure, clearing flooding etc).

Expert:  Doug replied 10 months ago.

Just keeping this one alive... any chance to check on those figures when the problem was occurring?

Customer: replied 10 months ago.
Must admit it seems better although there is no basis for logic there...Have been having pretty good starts. The few times it did do it I did not have my app dialed up. During those starts I DID notice there was no jump or pulse in dash tachometer the few times it occurred.
Expert:  Doug replied 10 months ago.

As opposed to normally seeing a little blip?

Customer: replied 10 months ago.
I don't know? On a normal or close to normal start I think the engine fires up before the signal gets to the built in tach?
Customer: replied 10 months ago.
Same with the app - by the time the engine fires the tach just blips a quick 174 or something and jumps up to 1350 or something on its way to idle
Expert:  Doug replied 10 months ago.

Yeah its real hard to tell on those.
That's the big benefit to being able to see it on the scanner when the problem occurs. Not to say that the sensor is cutting out, but we have very few options getting away from the expected fueling theory.

Customer: replied 10 months ago.
Refresh me on the fuel theory. You know the filter is built in the tank on the pump too and my buddy was maybe thinking that.
Customer: replied 10 months ago.
Almost going to half to shotgun a part at it its so intermittent
Expert:  Doug replied 10 months ago.

Well we were talking about a potential injector that was dribbling while sitting, causing it to be too rich to fire.
Pump is possible too, but its pretty rare to see them fail and when they do it isn't usually so sporadic, its usually all or nothing.

Customer: replied 10 months ago.
I agree on pump. We changed the 6 injector. Change others?
Expert:  Doug replied 10 months ago.

No, I wouldn't go that route on speculation alone, the misfire was enough to speculate on the #6, but thats it. I would say pulling the fuel rail and seeing if you have any drips while sitting wouldn't be bad... but honestly with #6 replaced (I wasn't clear you had already done that, I knew you bought it though) I would lean more electrical then.

Customer: replied 10 months ago.
after I change the injector a couple weeks ago with an empty fuel rail on the passenger side (post injector change) it fires right up - no hesitation/extra cranking. I take the dogs for a walk at our local park and come back - it cranks like 4 times. Doesn't do it again. BUT at the park the next day it does it again - both times i am parked at a sideways angle (like one wheel up on a curb). I am looking for ANY clues. It really HAS been better since those 2 times though. Very intermittent! It runs great - plenty of power. Idles a tiny but rough but always idles consistently and at the same steady idea speed. I wouldn't know there was anything wrong with the cylinder pressure if the check engine light was not on.
Expert:  Doug replied 10 months ago.

Ohh... well that is interesting.
If you go park in that same position will it do it again?
Have you noticed any correlation with fuel gauge position (perhaps given the information about the angle, if it is occurring at a lower fuel level there is some water being sucked up etc)?

Customer: replied 10 months ago.
Good point on fuel tank level but I don't really let it get lower that 1/4. Yea...will try same angle again and have app fired up. Also don't forget I have my nifty new fuel pressure gauge kit
Expert:  Doug replied 10 months ago.

I don't suspect anything noteworthy with the fuel pressure though right? If we were seeing it dip before a problem event we might try crimping off the fuel return line (leaky regulator for example) or the previously mentioned leak check from the injectors when pulled.
The sitting at an angle is interesting though... I'd like to see if that can be reproduced consistently or if it was just a fluke.

Customer: replied 10 months ago.
Will do that several times, monitor RPM, and advise in next day or 3.
Expert:  Doug replied 10 months ago.

Sounds good!

Customer: replied 10 months ago.
Man if I did not have 2 long start/crank events the same day that I changed the injector (a few starts afterwards) I would think that we fixed the long crank/starting issue. It has not done it since and It was slowly increasingly getting worse since the Spring of 2015. Makes no mechanical sense to me since it did it the 3rd start after changing the injector (same day) and I think 1 other time within a day or so of changing the injector. Check Eng light never extinguished BTW. It has only done it twice shortly after changing the injector and then not again since almost mid-January!
Expert:  Doug replied 10 months ago.

You might have nailed it... sometimes things just happen too and aren't related.
i might even consider doing a compression test again and see if we were off base on the compression loss if it continues to start happy!

Customer: replied 9 months ago.
I experienced 2 long crank episodes. On both I was in a hurry and could not capture RPM data. It was of my opinion that the issue was not corrected after the #6 injector replacement since I had 2 episodes directly after that. I guess I will just continue to monitor and continue to live with it until the condition starts firing us valid codes to troubleshoot it with or the truck does not start. I bought my daughters old civic off of her recently as she upgraded to a new vehicle so at least I have a backup to make the condition less dire/stressful and make troubleshooting the condition more "fun". I would like to milk this thing another 18 months (kids get out of college) until I go out and spend $41,000 on a new 4Runner as you know.
Customer: replied 9 months ago.
The 2 events were NOT when I was parked at an angle at the park this time BTW....
Expert:  Doug replied 9 months ago.

thanks.... well it was a nice thought anyway :)

Keep an eye on it and keep trying to catch it on the scan tool when it happens and we'll see what's what. The good news is at least it isn't anything that prevents use (always resolves quickly).

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