Tacoma not idling after TB and MAF clean - FIXED

I just cleaned my MAF and throttle body and Seafoamed through the brake booster hose and did not disconnect the negative side of battery? I should have? Truck seems to be running fine.

 

You're fine.

It depends on how bad the butterfly was. If you clean often, there will be very little difference and no need to reset. If you go a long time/distance, you'll have enough mung built up on the butterfly that the ECU will need to open it more to keep the engine idling.
When you clean it out, the engine will idle extremely high for a few restarts until the ECU relearns where the butterfly needs to be at idle.

You don't HAVE to reset the ECU, it just forces it to relearn everything. In my case, both my '03 Tundra and wife's '04 Rav4 did not idle worth a shit after resetting the ECU, so I lived with the high idle for a couple of days.

 

Think the poster is saying to get a new MAF. I'd still test it to be sure. If it is out of range then replace it.

On that whistle sound: you can use a piece of heater hose or similar to put to your ear and move the other end around the engine bay putting it close to various components, connections, gasket seams etc. while someone else reproduces the running conditions that produce the sound. Just watch out for moving parts like the belts and fan!!! Safety!

Could perhaps help you isolate what the sound is as will get louder in the location where the sound is coming from. The hose will "funnel" the sound the open end is near to up to your ear so you can often use this trick to find issues.

Let us know what you find.

Cheers

 

Thanks. I bought a OBD II scanner as I wanted to make sure on the MAF before just buying it - though I also bought a new IAC cause the other didn't seem to be working after doing the tests in the FSM.

I'm getting two error codes: P0100 Mass or Volume Air Flow Circuit Malfunction

P0110 Intake Air Temperature Circuit Malfunction

these are from Toyota nation. My scanner says P0110 advices to check the wiring/connector harness for the MAF... I had read the MAF with a multimeter and it seemed bad.

I'm unable to start the taco at all. Before I was able to start it and keep it alive with the throttle but that doesn't work now either. Would a bad MAF cause that or is something else afoot?

Would a bad starter cause an error code on my scanner. Are there any parts that WON'T cause error codes. I haven't worked on/tinkered with anything besides what was mentioned/worked on in the OP: TB, IAC (replaced) and cleaning of the MAF.

Thanks for all the tips and assistance folks

 

Codes are generated from the emissions system.
Generally, the only non-emissions components that will trigger a CEL would be the transmission, and it will simply trigger a "command CEL" code (typically can't read the trans code with a regular scanner).

A bad starter will not generate a code unless it's dumping the battery... low battery can cause all kinds of false indications.

So you mention bad starter... is it cranking but not actually firing? If it's cranking, your starter is fine.

 

yeah, its cranking. Battery was at 75% but charged it just to be sure it wasn't a battery issue.

I saw a thread where someone mentioned their taco not starting due to an alarm issue. I got my taco used with no alarm key and only found out later there was a kill switch on the right driver side panel - whenever I disconnect the battery negative lead the alarm always goes off and I have to put the key in the ignition, turn it to ON and then hold the button to stop the alarm. I'm wondering if when I did the ECM reset thing by holding the high beams momentary that it cause something with the alarm to trigger - like a starter prevention. Could that happen? Since I don't have the stock (or any) alarm remote, I'm not sure if the alarm, or all aspects of it, are completely disarmed.

Perhaps the switch on the panel for the alarm just stops the alarm sound??? Doesn't seem like it would be a practical implementation in terms of wiring but its something I just thought about. Cause before, when the truck wasn't running - that is in my OP, the truck would start and run if I held the gas but no idle. No its not starting at all.

 

If the alarm has an engine immobilizer, it will normally disable the starter and not allow the potential thief to crank until the battery is dead.

And even if the alarm were the cause for it not starting, it would not generate the CEL codes you're getting.

It's been over a week now and you don't seem to be getting anywhere. I'd take it to a shop and tell them EXACTLY what you did and how you did it so they know where to look. The forum isn't going to be much more help without having eyeballs on your truck.

 

Sounds like the button you describe is the standard valet button most commonly mounted on the driver kick panel. As above, most alarms installed just shut down the starter circuit so you'd have no starter if it was an alarm issue.

Make sure battery fully charged.

So, codes saying MAF/intake related. Make sure your intake hose is on correctly with no leaks or missing connections. If intake okay, check the plug to the MAF to ensure no issues with it and that it is correctly plugged in all the way. If all okay and plugged in fine then test the MAF with an ohm meter paying attention to the temp. Chart info and correlation to temp already given in previous posts. If the MAF tests out of range then you have the support of the pulled codes and the straight ohm meter test to let you know that you need to replace the MAF. As it says in the FSM, if the MAF does not test to the ranges given by temp then replace it.

Hope that helps.

If you are still concerned with the proceedure, testing or replacement of parts then agree with above, probably best to get it to the dealer and have them check it for you. Be sure to tell them what you have done and what you have replaced. I would not mention testing the maf and thinking it was that, let them do the tests and figure out what it is.

Cheers

 

yeah I tested the MAF with a multimeter as mentioned in a prior post and it didn't read correctly. Not sure if a bad MAF would totally cause a no start. I also ordered a fuel filter cause I doubt mine has been replaced.

I haven't checked the spark plugs yet (got like 10k on them), not sure if they could be bad - though I seafoamed the truck about 2 weeks ago - had read "rumors" on TW or sparkplugs needing to be replaced post seafoam.

I got a MAF/FFilter coming - should be here Friday/Sat, if that doesn't fix the issue I'm having it towed to a dealer.

Is there a way to test wiring harnesses? like for the MAF and for the IAC and Throttle Sensor?

 

FIXED. MAF arrived yesterday, put it in today - I was getting MAF and Intake wiring harness codes prior to replacing it. Codes went away after so the MAF was bad.

Taco wouldn't start at first - had to crank it and give it some gas and it eventually turned over and started. Seems to run good. Took it for a drive, came back, turned it off and waited. Moment of truth; it started again fine without tying - problem I had which spawned all this was not wanting to restart sometimes when the engine was warm.

Thanks for all the help. Case closed.

 

looking over all this I may have missed it. Didi you clean the butterfly? I've seen lots of people replace MAFS because of codes but in reality they had dirty TB blades. Your hot start problems can be idicative of that also. Just wondering.

 

Ya I cleaned the tb butterfly thoroughly. And it was dirty. I didn't test the MAF prior to cleaning it so it MAY have been going bad; can they go bad/work in and out or do they just die? Or my cleaning the MAF with the cleaner may have broke it. Seems to be running good still.

 

Strange.

 

I think after cleaning the MAF and then running the truck, the MAF went bad, maybe the computer didn't notice it at first or maybe the MAF finally gave on the short drive and when I turned off the truck, when I went to restart it the CPU then recognized the MAF was bad.

 

Hooray!!!! Glad you sussed it and all is working now.

 

I'm digging this up because I had the exact same issue. After cleaning the TB and Idle Air control Valve, the problem seems to have been eliminated. BTW for reference - my 01' 2.7 L has 238k on it.....

Hopefully this will help someone else too....

 

Yup, my 2001 2.7l was having the exact same no idle issues yesterday. Weird thing is, I cleaned my MAF about 6 months ago, no problems since. Its does have 220,000+ miles. After a few trips with one foot on the gas and one on the brake , it started working like normal. If it comes up again, ill know where to look.

 

That's great news. Out of curiosity, are you having any other issues with your 220k 2.7L ?

 

No issues other than that.