Truck is 86 22re 5sp 4Runner. When I try to start it if it’s the first start in the morning sitting overnight it cranks and won’t fire it takes about 4 tries. It might catch and fire once but not run. Turning key to start and not pressing clutch I can hear fuel pump buzz and pressure moving through the lines but it doesn’t seem to help it start.

Its 100 degrees where I live. Cold weather or hot weather same issues.

if I let the truck sit for longer than 24hrs. Let’s say 3 days or 1 month. It starts perfect. Fires right up in like 1-2 seconds.

Battery reads 12.4v when key in on position. The b+? Terminal at the check connector gets 12.3. And at the fuel pump it’ll read 12.1 or so.

Checked ohms on cor and they are in spec.

Can anyone help. Trucks had this problem for like 10 years.

Fuel filter is new

 

Bear in mind that sitting overnight, the pressure in the system (fuel) tends to bleed off...

Have you tried holding the key to start without pressing the clutch until the sound of the fuel pump changes? Mine seems like that when it changes, it drops in pitch a little. Not a lot, but a little. That's when the system is up to full pressure. If I release the key, press the clutch, then turn the key to start again right away, it fires right up.

Remember, 100° F may be warm (or hot) to us, but to the engine's sensors, it's cold. As in not warm. Is it possible the cold start injector timer sensor isn't sensing the correct condition, and not activating the cold start injector? Or that the Aux Air Valve is sticky and not opening correctly? Maybe over a few days, or a month, as you said, whichever part isn't functioning, or only partly functioning, finally clears itself, allowing the nice, quick, easy, start?

When I lived in Yuma, Az, my 4Runner acted the same as yours is. It could be 120°, or 90°, didn't matter. When I rebuilt the top end, after a "friend" cracked the head for me (never let friends borrow the truck!!), I found the aux Air Valve was a little sticky. I lubed it with a drop of oil, and 90% of my starting problems went away like magic.

Also, are you timing, or idle speed, set properly? Maybe it's having some trouble due to the timing, or idle speed?

Just my thoughts on the situation...
Pat☺

 

I can hear the change in sound when turning the key without clutch pressed. But it will still have some trouble starting.

I will I’ll look into the aux air valve. Never heard that mentioned before.

Ive checked the timing with a light gun but nothing out of the ordinary.

thanks pat for the suggestions

 

Bear in mind, it takes both fuel and air to make for internal combustion. The Aux Air Valve provides the extra air needed when the cold start injector is dumping extra fuel in. It senses water temperature with a water line to the water pump, and when it's "cold" it opens, presuming the cold start injector timer is sensing the same condition, and activating the cold start injector. Thus, extra fuel AND air supplied to the intake manifold when the engine is "cold". When the gas pedal isn't depressed at all. This system only works at idle, once the gas pedal is depressed, the aux air valve and cold start injector are out of the equation.

The Aux Air Valve feeds air in after the idle adjust screw. You can see it's line to the TB pretty easily. Large rubber air tube going into the bottom of the throttle body from below, over on it's left side as you face it, looking from the front of the engine. Large is relative too, BTW. Like 3/8" or 1/2" diameter line. Just follow it down a few inches to the Aux air Valve. The Valve is held onto the bottom of the throttle body with two bolts. Pretty obvious, really, once you know what to look for.
Cold is relative to the engine, not us, don't forget.

Good luck to you!
Pat☺

 

Hey I finally got around to changing that aux air hose which fixed a different issue I had and I sprayed some penetrating fluid to loosen the valve and It has helped the starting. Now it’s in the 60s where I live and it’s not perfect starting but it’s a lot better so I have some more things to investigate.

 

the overnight hard start, but easy start after 4 or 5 days is a hallmark of a leaking fuel pressure diaphragm. after letting the engine run for a while (a few minutes would be sufficient), turn it off, wait about 10 minutes, then pull the vacuum line off of the pressure regulator to check for the presence of raw fuel. there shouldn't be any. if there is, you've found your problem, and the fpr should be replaced. if there isn't raw fuel in the line, the fpr is probably ok, and the problem is elsewhere. it's a simple test that costs nothing to check.

 

This hard-start issue is hard - LOL! You think you've figured it out... I did not have the issue for 4 years after doing CSI on my CSI system. Then after I replaced my radiator/temp gage sender it came back.
Thanks for these^^^ 2 more things to check.

BTW, the fuel pump kinda sounds like a faint whistle, correct? That's what I hear when my C.O.R. is closed.

 

kind of. the check valve in my pump probably doesn’t work, so when the pump first turns on, it’s a bit high-pitched, but changes to a deeper growl after 2 seconds. the change in pitch is noticeable.

 

Depending on how long it's been shut off, the fuel system will eventually depressurize. After it does, when you first fire up the fuel pump, it will have a higher pitched sound. After the fuel system is fully pressurized, the sound drops in pitch.
When my 4Runner's been sitting couple days, it does this. I first turn the key to start without depressing the clutch or the Clutch Start Cancel switch. I listen for the fuel pump to change tone, back the key to ON, and then push in the clutch, and she starts right up. If I don't do this, it actually will turn over more than 3 times before it starts! I know, that's hard to believe, but I might actually hear it turn over 5 or 6 times before it starts if I don't "pre-pressurize" the fuel system!

Seriously, though, the book specifies that the fuel system should hold pressure, 21 PSI minimum, for 5 minutes, after the engine stops running.. If it doesn't, the book says to check the fuel pump, pressure regulator, and injectors for the leakage.

Good luck!
Pat☺

 

you can save your key tumbler some wear by not releasing the key back to on, pushing in the clutch, and then turning the key back to "start". instead, once the pump changes "tune", simply push in the clutch pedal while the key is still at "start", and it will start. two fewer steps.

 

Half the time I'm not in the 'Runner when I start it so it can warm up for my wife.
She's very limited mobility (I'm only slightly more mobile), so she climbs in, with help from me, and sits in the truck to wait for me. I always do a short walk-around, and double check the fluids, before I start it. Once that's all done, I fire it up and go do other things. Go back to the house for forgotten items, go up to the end of my driveway to get the paper, take out the trash, bring in the can, load her walker into the back (not that easy any more for me), whatever. I always start it asap so she can get warmed up as soon as possible.
Anywho, I just stand outside, lean in, and run through my start sequence. THEN I go do whatever still has to be done before we leave. We only use the 4Runner in the winter time, and it gets a bit nippy around here in the winter. That's why I do things the way I do. I want it to warm up as soon as possible after my lovely wife gets in, so she can be comfortable. I can even top up the clutch reservoir, brake reservoir, recovery tank, whatever, while it warms up.
Hard to push in the clutch pedal standing beside the truck

I also figure, it's a 32 year old truck, so giving it a little warm up time before I start driving it won't hurt anything. I do the same thing for my pickup, which we drive in the summer time. I fire it up, do whatever I need to, and, since I live in a development with a 15MPH speed limit, I can let the engine run on high idle, all the way out. It putters along in second on high idle just great. By the time we get to the actual paved, public, roads, the high idle kicks down, and off we go.

Sorry, I ramble. That's why I have the 2 extra steps in my way. You're right, though, your way would save wear on the key, both tumblers and the switch.
Have fun all!
Pat☺

 

I almost always use the safety cancel switch while in neutral to start (Feels like a push=button Prius - LOL), because to a lesser degree I do like Pat does; adjust mirror, seatbelt, radio station, check on things all of which give the engine some time to warm up. Also as much as possible in idle until needed to rev up for the main road. I think the engine likes that.

 

even using the clutch cancel button, you can do the same thing. turn key to start to "prime" the efi system, then push the button while holding the key at start.

 

By the way, my hard cold starts are so random. In Utah's and Mammoth, CA's below-freezing temps last week, it did not happen as much as in San Diego (although I could hear/feel the battery struggling to turn the starter- LOL!). Could also be that the CSI timer switch resistance actually gets low enough to fire the CSI when below freezing, OR there is a very narrow range of temps when combination of CSI timer switch, and the ECU temp sender and ECU program work flawlessly?

 

thank you for the suggestion. I did check this and the vacuum line looked bone dry