helikyler

Hey all... I've got a 86 4runner with about 60K miles on the engine.

I've always had issues with it starting on the first crank (or two) for a long time. Rebuilding the engine didn't fix the issue. The mechanic said that tuning and the peripherals weren't part of the rebuild... lame.

When the truck has sat for a day or more, it takes about 10+ cranks now to get it to start. I think that it's not getting enough fuel.

I suspect:

• the fuel pump may be weak and going out?
• the fuel lines could have a leak and losing prime?
• the Idle Air Control valve is worn out or needs adjustment?

What I know:

• the battery is strong, I just recently replaced it
• the starter is strong, though this issue wears them out faster (had 3)
• the truck starts easier in colder weather (~60 or less) but not perfect
• starting throughout the day is fine, but the first after 12+ hours is where it is hard to start

I can't really afford to assume it's the fuel pump and replace it so I'm looking for advice. Any help is appreciated!

JasonYota

iTrader: (1)

How does the truck run once you get it running?

mldave

I'm surely not a mechanic but my similar troubles on my 86 truck was the cold start injector time switch.A friend bypassed it for me and never had trouble again.Many threads on this site about the procedure.....https://www.yotatech.com/forums/f116...-bypass-68706/

helikyler

@JasonYota: It runs great. Needs a valve clearance adjustment but otherwise good!

helikyler

@mldave: thank you much! I will DEFINITELY look into this right away.

helikyler

Hey mldave... could you explain how your setup ended up working? Do you have to toggle the switch every time or do you must leave in a certain position? Or switch it based on ambient temperature?

I read the thread and it looks compelling. So did cleaning out the IACV, too, until I realized I have the 22REC that the other guy mentioned so I don't know if mine is the same as pictured.

scope103

The fuel pump does have a check valve, and if it starts to leak it will make it harder to re-start (the pump doesn't start until the starter does, and it takes a second or two to re-pressurize the rail). But 10 cranks is too much.

BUT: this is very easy to check. Jumper FP to B+ on the diagnostic connector. Turn the key to ON. The pump will start immediately (you can hear the Fuel Pressure Regulator doing it's job; it should have a steady sound w/i 3-4 seconds. If, instead, it sounds like it's slowly winding up, that's probably a weak pump.) Once pressurized, remove the jumper, and try to start the truck. If it starts fine, the problem is almost certainly in your pump: replace it.

If that DOESN'T make the problem go away, your problem is not fuel-pressure related. Look elsewhere.

mldave

helikyler,I usually just toggle mine once in the morning,unless it's been half a day or so.The toggle on mine is on the left of the steering wheel and it is graded for automotive use. I push the toggle down after it starts as it seems to flood when you start the truck again if you leave the toggle up.Another thing I have is a starter relay bypass button on the right of the steering wheel as these rigs from 86 are knowm to have bad relays and sometimes you turn the key and don't even get a click.On the button I put the stick in neutral with e-brake on,turn the key to on without cranking and push the button.Starts right up without turning the key.

gte718p

Could definitely be a failing fuel pump. On my current truck I was having problems with a cold start. I found a hole in the intake pipeing. Once the truck was warm a little extra unmetered air wasn't bothering it to much, but cold it was really struggling to start.