Tacoma not idling after TB and MAF clean - FIXED

I'd install a new o2 sensor if its got over 100k and considering all the sludge thats just been put through it.

 

maybe go to a junk yard find a maf. I'm thinking not disconnecting battery might have caused a short. Otherwise idk man vacuum leak? Gl

 

Yes maf will throw light

 

Is the o2 is the one on the front of the exhaust? I replaced that when I got the truck - 10k ago. First thing I did when I got the truck as the check engine light was ON because of the o2 sensor so its good.

Maybe I didn't explain myself correctly about disconnecting the battery:

I disconnected the negative lead before dismantling the throttle body and doing all the work...

I was confused in the prior posts about what to do regarding the reset with the high beams switch.

So the negative was disconnected the whole time I was working on it.

Yeah, my friend said it would, as I mentioned; when I run the truck I don't see the check engine light. Wondering if its the IAC...

 

When I cleaned my MAF and TB I disconnected the neg battery terminal and removed the EFI relay before I started the process, then put it all back together after I was done.

It took my truck about 2 minutes to relearn everything.

I would try that and see if it helps.

 

Anyone know ways to test the iac that don't involve the engine running?

 

Check the resistance between the prongs. No or very low resistnace indicates a short.

If you have a whistling, there's a vaccum hose disconected or a missing vaccum plug. I would check and double check your vaccums if I were you.

 

Here are various tests. Hope they help.



This one does require run, but good to have if you don't already.
I do the same as Madjik although I don't remove the fuse. Maybe I should. I work on the truck and do enough stuff that the battery is disconnected for a while.

Upon restart I start the truck up and hold the idle at around 2000 for about a minute. Then drop off the pedal so that it drops to 1500 or so and then after about a minute of that I let off the pedal and let it idle until it warms up. Idle will eventually drop down.

By the way, to answer your question about the liquid from the start of this thing, that is a bypass hose system off the coolant system. One hose connects each side to run coolant through.

Okay, when you first were going through this my first thought was the IAC being gunked up due to throttle body crap running down and into the valve. BUT you said you removed it and cleaned it so then thoughts come to operation.

Would not hurt to double check all connections and check vac hoses for cracks etc. The measured Mass Airflow depends on temp. So be sure to take that into account.
Not saying that you still could not have a bad mass, but just to double check your testing proceedure.

More to my mind is that this was an existing issue that got worse once you did the cleaning.

A good point above about the whistling. How bad is it? Have visions of way back when we put a tunnel ram on a z28 and it sounded like it had a blower on it as it whistled so much. Found gasket had slipped and was an air leak. Hmmm, I assume you removed the throttle body. All back together right and gaskets good? Air hose connected correctly. No issue with the butterfly position? Just free thinking here.

 

don't know if this will help, but when I got my truck the only code it threw was the IAC, had it read, then removed throttle body and it and cleaned both, no code.
now this is not written in stone, but years ago I was told before doing stuff like this unhook neg battery cable for at least 30 mins to reset computer.

 

I didn't remove the internal part of the iac though; didn't have the star tool, I just removed the whole iac which has the hose connections. I just cleaned that area; not sure if that really cleaned the iac enough.

Are you talking about checking resistance for the MAF or IAC? cause the FSM manual said to check resistance for the MAF - which I did, just want to make sure you're talking about the iac - that it can be measured for resistance as well, like the maf. I don't recall seeing that in the FSM.

 

You don't have to remove the internal piece on the IAC to clean. It pivots and you can see it with the IAC removed from the throttle body. A good flushing and cleaning should be good enough. Should be pretty obvious if it has crud down in it.

While it is off, simple enough to check operation for open and closed as per the FSM page.

IAC can also be tested for resistance according to the directions in the second FSM pages I posted. As you are not able to run it you can test using the COLD section which says it is from 14 to 122 degrees F. Ohm meter to the B+ terminal and then the other terminals. Should read 17 to 25 ohms. If out of range it says replace.

I hope that helps.

Cheers

 

thanks but you linked the 5RZ part of the manual...

my taco is a 2.7 3rz, from looking at the MAF inspection section of the manual - the test points for the MAF are different. I had tested it using the 3rz method and got a crazy reading. However I also read the two left terminals (as specified using the 5rz portion) and got a normal reading...

 

See, that is what I get for assuming Saw the SR5 and Prerunner and assumed a 3.4.

Looked at your link for MAF testing. Test still is temp specific. At temp of 68 degrees you should be in at 2-3 ohms testing as shown in the fsm. If the temp is higher then the ohm reading should decrease. If the temp is lower then the reading you get will increase. So, let's say temp is 90 degrees and your test gives you a reading of 6 ohms. This would be out of range as the ohm reading should be lower. You'd then need to replace the MAF.

Assume you've found the IAC stuff in the manual, but if not yet then:
This can be done without the engine running.

Other test assumes you can get it running right to start with by the look of it.

Hope that was of some help at least.

On the MAF, maybe you can give a temp and ohm reading. Oh, and I guess would be good to know how good a meter you are using. Only mention as I was checking some subs I bought and used a Harbor Freight meter they were giving away free with purchase. No wonder! Tested a 2 ohm coil and was getting 4 ohm range readings. Had me contacting the seller about it before I thought I'd double check the readings with my TPI. 2 ohm no problem. Cheapo Harbor Freight digi meter went straight in the bin.

Retest the MAF and if not too much of a pain, test the IAC with the above test at least and post up your results.

I know you've checked, but look closely at all your plug connections, air hose installation and vac hoses again just to be sure. No problems with the gaskets on the throttle body and IAC when reinstalled correct?

 

Do I just disconnect the negative lead, pull the EFI and wait or reinsert it and then reconnect the negative lead?

I also tested the IAC and from what I could gather it was bad. I got a new OEM one - a friend works at a shop so I got it for less than usual. Truck still wont start...

Also, when I got the truck, it didn't come with an alarm key. I didn't know it at the time (when I bought it) but there is a kill switch on the left driver side panel. Whenever I disconnect the battery and reconnect it, the alarm goes off and I have to put the key in the ignition and push the button to bypass the alarm. My question is - is it really bypassing the alarm, since I did the negative lead removal/high beam thing, could it have reset the alarm in a way that is causing the truck not to start?

 

I don't think the EFI relay is going to help your issue, but to answer your question: disconnect the negative lead, pull the EFI and let it sit for about 30 mins before putting it back in and reconnecting the battery.

 

he bypassed having to wait by flipping the high beams on..

op is everything connected take a good hard look touch everything.

any smoke after starting (after cleaning) maybe give it some throttle try to run the bullshit out.

also maybe check fuel pump?

we just need to have some fellow tacoers come help you out.

op also i know you disconnected negative before spraying maf but maybe you got it too wet (your supposed to spray it indirectly)

just trying to help best i can but i cant think of anything else

 

Btw need to replace plugs soon if you haven't already.

 

Thanks. No smoke after cleaning. I did take a pretty dang hard look: both the water bypass lines are connected to the bottom of the IAC. The IAC connector is on and the one for the TPS. All vacuum lines and evap hose. New gaskets for both the TB and IAC were used.

Would a dead MAF cause it not to start?

Ok, i'm confused - to you mean coil packs? or the wire harnesses for the coil packs?

 

Yes. it will op jack one.
Then check plugs.

 

heh, what does that mean?