Toyota 3.4 hard start issue

YotaOnRocks

YotaOnRocks

Well-Known Member
Joined
Jul 17, 2007
Location
Madison
My 97 4runner 3.4 4wd w/5spd has around 310k on it and for the last 60-70k miles it has had an issue that is rather annoying, and I would like to try and resolve it sooner than later if I can figure it out.

If I drive it for at least a few miles or for 3-4hrs and get it up to temp and shut it down and it sits for more than about 10 minutes or less than a hour and a half or so, It doesn't want to fire back off. It will sometimes stumble the first time it turns over but then nothing but the engine turning over. Occasionally I can hear it backfire through the intake as it finally starts to run.

When it does this, it usually takes a couple minutes of 20sec on 20sec off of the starter before it will run. I never smell fuel when trying to start. A few times in the very hot months I had it act like it was going to start acting up when I went to leave work and it had been sitting all day in the heat.

I have cleaned the MAF but done nothing else to try to solve this issue. I initially thought the check valve might be bad in the fuel pump but that doesn't explain to me why it starts normal after sitting. Only code it has is for an evap purge. Has had that code since I owned it. I went to try to check the fuel pressure when it was acting up one day and found that Toyota provided no provision for doing so in the factory fuel rail or line.

Any suggestions or ideas are welcome.
 
I had a first gen 4runner with a 3rz swapped in that would heat soak some sensors on the back of the engine and it would not re-fire if sitting for 15 or so minutes after a drive. I had to wait at least 30 mins for it to crank back up. Hotter days were worse. It would crank and crank but not fire. Then all of a sudden it would fire and run great. Kinda frustrating.

I've heard of similar issues with the 6 and 4 cylinder.
Never fixed it. That's all I got.
 
Does it idle ~800-900 when it's warm, or does it run higher? If so, check the IAC (idle air control). They get gummed up and can cause hard starting issues. It doesn't look like it, but it can be removed from the throttle body and cleaned.
 
maulcruiser said:
Does it idle ~800-900 when it's warm, or does it run higher? If so, check the IAC (idle air control). They get gummed up and can cause hard starting issues. It doesn't look like it, but it can be removed from the throttle body and cleaned.
Click to expand...
Idles around 800 and very smooth and steady. It even usually idles correct as soon as it fires after giving this issue but occasionally will stumble a little for a second or two. I had decided not to tamper with the iac since from what I could tell, it is working well, but if it is a possible culprit, I will.
 
Back
Top