P0505 (IAC) Problem

[Bill_Dunnigan]

P0505 (IAC) Problem WITH PICS!!!!

Hello all, I'm new here and plan to post up alot of threads. I just traded my old 2004 jeep wrangler all lifted up with 133k miles for my new to me 2000 SR5 with 82k miles!! I'm psyched!!!! anyways the SR5 has some slight issues, the main one being the p0505 CEL. I tried spraying some carb cleaner into the throttle body, but its cold here (about 15 degrees) and i don't think it helped.

The symptoms are:

when i try to start rig when its cold it wants to stall out right away unless i give it some throttle for about 7 seconds minimum. once it warms up, it fine.

another symptom is a high idle. It idles around 1100-1300 rpm. is this normal for the V6? any input from you guys would be great. thanks all, and wish me luck.

Edit:

also forgot to add, my gas mileage is horrendous with this CEL. Half a tank in less than 75 miles.

 

[matthinnant]

I would suggest cleaning the throttle body and doing some sea foam through the airlines but I dont suggest spraying carb cleaner straight into the TB b/c all your doing is just putting all that backed up carb and gunk back into the engine. Take the TB off and do a proper clean job and replace the gasket while your at it, but other than that welcome to the club and goodluck with your issues

 

[PitbullRescuer]

IAC being Idle Air Control valve? (I think anyway). It's actually located under the top plenum toward the front of the motor. Looks like a CO2 cartridge. Pull it off, clean it and reinstall.

Wait for others to comment though, I don't want to swear to what I just said. LOL

 

[quicksilvr]

I tried to fix a P0505 on a friends '99 Limited about a year ago. I removed and completely cleaned the IAC, and tested it while it was out. It worked perfectly and was 95% as clean as new when I put it back in. It didn't fix it.

I also did all the other normal "cleaning" items (MAF, TB, intake, etc). Didn't fix it.

His truck also throws a couple other codes now too....and it leads me to guess that the fix is a new front (upstream) O2 sensor. It's not a bad idea to clean all that stuff....but I would probably plan on putting a new front O2 on no matter what. It's only about $90, and will almost always make the truck run better and get better gas mileage.

If you have a 2000 4x4 automatic with two cats (cali spec), then your front sensor is a Denso 234-9002.

If you have a 4x4 manual trans with two cats, it's a 234-9001.

If you have a 4x4 with ONE cat (auto or manual, doesn't matter), it's a 234-4162

 

[Bill_Dunnigan]

alrighty..... lets give an update!

So today at work, I removed the throttle body assembly (including the IAC) and completely disassembled it. sand blasted all aluminum parts, and cleaned all the grime out.

I had a family of about 20 spiders living in the spring mechanism near the TPS and lots of corrosion. After the sandblast and cleaning, it looks like a brand new part, litterally.

In the IAC mounted to the bottom side of the throttle body, I found a piece of a stick or some type of contaminant, which was actually seizing up the rotating assembly and not allowing it to open or close. I cleaned out that pretty thoroughly too.

put everything back together after cleaning the metal gasket and top manifold mounting surfaces.

I have not reset the computer yet! I had to leave work cause it was getting late.

It is still reving high, actually much higher, close to 2000 rpm at idle when its warm. so my question is, do i just need to reset the computer, or do i have to readjust something in the throttle body/IAC? Some Pics Below

After intake tube has been removed

Out of the rig, took about 20 minutes in the cold with basic tools!

Spiders

More Spiders!!!

This is the pic of the stuck debri blocking IAC iac ROTATING ASSY.

ALL CLEANED UP!!!

 

[Bill_Dunnigan]

another update...

so, i pulled the fuse for the EFI and took the wife out to dinner, hoping that the check engine light would go out and the revs would be back to normal (700-800).

well got back from dinner popped the fuse back in and started up the rig. It now starts with no problem, and the check engine light is off!!!! yeah!!!! but the revs are still very high, 2000rpm at idle.

so now I'm thinking the culprit is a vacuum leak somewhere. anyone have any helpful hints on where to start?

 

[matthinnant]

wow that sandblasting did a nice number on your TB and as far as the spiders go your a bigger man than me b/c I hate a spider more than anything. Im glad to hear that your CEL is gone and goodluck with finding the vacuum leak

 

[Bill_Dunnigan]

so tomorrow I plan on replacing all vacuum lines, I figure it shouldn't run me more than 50 bucks.

hopefully this solves it!

i'll post pics later tomorrow

 

[kball]

You might try just driving it for a few days. It may just need to relearn the "new" clean IAC and then the idle will settle down.

 

[Cheif4Runner117]

I tried to fix a P0505 on a friends '99 Limited about a year ago. I removed and completely cleaned the IAC, and tested it while it was out. It worked perfectly and was 95% as clean as new when I put it back in. It didn't fix it.

I also did all the other normal "cleaning" items (MAF, TB, intake, etc). Didn't fix it.

His truck also throws a couple other codes now too....and it leads me to guess that the fix is a new front (upstream) O2 sensor. It's not a bad idea to clean all that stuff....but I would probably plan on putting a new front O2 on no matter what. It's only about $90, and will almost always make the truck run better and get better gas mileage.

If you have a 2000 4x4 automatic with two cats (cali spec), then your front sensor is a Denso 234-9002.

If you have a 4x4 manual trans with two cats, it's a 234-9001.

If you have a 4x4 with ONE cat (auto or manual, doesn't matter), it's a 234-4162

This is what I'm going to try first definitely makes sense, I replaced the downstream over a year ago cuz a light came on on my 2000 Limited, but I disconnected the battery before seeing what the code was. Anyway thanks for this, cuz I've messed with iac valves and they rarely fail unless there is a wiring issue, even if there dirty they still work unless it's like 25 years old and clogged.