IAC + Starting Problem - Please help

[4runnerTiger]

So for the last week what I assume was my IAC was acting up.

The symptom was running fine but when I parked and went into park the engine would idle very high, around 2K when warm. Upon initially starting when cold it would idle around 1K, before this problem when warm when in park would idle at around 7-800rpm.

Yesterday after a 20 min drive, i moved the car a very short distance, and shut the car back off, when i went to restart it, it woul dcrank but wouldnt turn over. Eventually, it did start and got home.

This morning I cleaned the MAF, the throttle, and the IAC. Now it will crank and try to start but will not actually start. I have double checked all my connections, and everything is plugged back in. It has been sitting about 2 hours since i finished with the battery disconnected and it still is displaying the same condition.

Can anyone give me a direction to go? Would left over MAF cleaner or Carb cleaner in the throttle and IAC do this? Anything I should disconnect to let it air out?

Thanks in advance!

 

[Gerdo]

Did you see my thread? http://www.toyota-4runner.org/3rd-gen-t4rs/90760-engine-cranks-3-times-too-long.html
How does it start when cold?

 

[4runnerTiger]

It was starting fine when cold. This was a 100% warm engine issue.

 

[Gerdo]

It was starting fine when cold. This was a 100% warm engine issue.

That is what mine WAS.
I still don't believe that it was a bad fuel pump, but it was.

 

[Bill_Dunnigan]

Here is a write up I did on the IAC and throttle issues. good luck


http://www.toyota-4runner.org/3rd-g...ottle-body-adjustment-including-iac-pics.html

 

[4runnerTiger]

So I pulled codes and got a P0100 a P0101 and a P1300. The first 2 seem to indicate a MAF failure. I did clean the MAF using the proper MAF cleaner but went ahead and ordered a new guarenteed one. The igniter seems to also be at fault? but I am going to do one before the other.

The symptom is what is throwing me, the truck wants to start almost starts then dies. So crank, starts right away goes to like 500 rpm and dies like 1 second later. Imagine the tach has enough time to go up to 500 then back down to zero.

Any ideas?

Also what is the black plastic "rail" under the throttle body called? It would appear that the coil packs are on top of it?

 

[LittleCaesar]

See where the MAF cleaning and a new one gets ya. Clear the codes by taking the neg battery cable off the battery for two minutes at least, then reattach. Then report back.

 

[4runnerTiger]

Solved. So what I did was go around the engine and unplug every sensor try and start and see what the result was.

MAF - unplugged same condition.
New MAF - same condition.
Igniter - unplugged no start.
TPS - (backside of Throttle) unplugged no start.
IAC - unplugged same condition.
COIL Pack center cylinder - Same condition - BUT when I plugged it back in suddenly high idle 1500 then 500 then stall.

Started over with unplugging and starting:

MAF - unplugged new condition (start and rev to 1500 then 500 then stall).
New MAF - new condition.
Igniter - unplugged no start.
TPS - (backside of Throttle) unplugged no start.
IAC - unplugged Started and Idled at 800 RPM

EUREKA!!!!

Plugged IAC back in and everything works properly... including IAC.

So... when cleaning I unplugged coil pack #2 in the center and i think it didnt get all the way plugged back in causing condition 1, a 500 rpm idle and stall.

When that was resolved the cleaned IAC was I assume stuck open? or had some problem preventing the engine from starting. Once the engine warmed up I assume it was able to reset the cleaned IAC learn its parimeters etc and now is running better then before.

I will keep an eye on the IAC but the original condition of high idle in neurtral or park is gone for now.

 

[LittleCaesar]

Don't overthink it. Enjoy the normal idle.