Wants to die upon startup and big loss of power on highway

1995 Tacoma; 2.4 engine; automatic; 108,000 miles. Check engine light came on and I found an extremely dirty air filter (2 years old) and acorn shells and pine needles in the filter housing. Replaced filter and cleaned the crap out. Cleaned the MAF sensor with carb cleaner, the O'Reilly clerk said it was okay to use this. Also removed the rest of the air duct assembly up to the throttle body in order to clean it. I had put it off for over a year and just living with an annoying sticking butterfly valve. Man was it dirty!

So I managed to get rid of the sticking butterfly valve problem, but now it wants to die repeatedly on startup and has a bad loss of power going down the road. Running smoothly just no power. Makes me think of bad fuel delivery.

It really was running fine before I went and messed with it. Fuel mileage was good at 25 1/2 to the gallon. Had a bit of a rough idle that shook the engine/truck that seems to have gone away now.

I don't know what to think other than I must have screwed up the MAF sensor. Help?

 

Go get some dedicated MAF cleaner. Nothing else. Don't use brake cleaner, carb cleaner or anything else. The MAF sensor has a thin layer of oil on it now from the carb cleaner.

 

Close encounter of the 3rd kind

 

And if that does not clear it up, buy a new OEM MAF and DO NOT TOUTCH IT WITH YOUR HANDS!

 

Disconnect your battery for a little to reset your ECU, computer might need to re-learn its settings.

 

Thanks for the response you guys - The 'ol man wrote the OP earlier, but it does look good that he may have already pinpointed the issue. He just now had to drive the thing into work for his overnighter, and boy was that thing sputtering horribly. I was worried I might have to take him into work myself.

I'll let him know about getting the special cleaner. Do you think that MAF cleaner will be at an auto parts shop, or is it something I'm going to have to order somewhere?

 

http://shop.advanceautoparts.com/p/crc-mass-air-flow-sensor-cleaner-11-oz.-05110/7070079-P

Even Home Depot has it.

 

Okay, got the MAF cleaner located and went to look for replacement sensors and.... Wow. These MAF sensors are freaking EXPENSIVE. I'm finding that some listings on these that say they'll work on either the 2.4L and the 2.7L engines. Does this sound right to you guys?

 

I got mine for my 2004 3.4V6 on Amazon for half the price of Vato Zone or O'reilly's

 

I'm a huge fan of Amazon and ebay. Online shopping is no prob. But what I'm really looking for right now is confirmation that a sensor that works for the 2.7L can work for the 2.4L...??

 

Change your fuel filter while you're at it!

 

Have you ever messed with the spark plugs? How long have you owned the truck?

 

We've had it for a couple of years, and I think he did change those out when we got it back home. I'm not sure about the fuel filter though. (I just managed to locate that fuel filter on the parts diagram... that looks hard to get to!) I mentioned the spark plugs as a possible source of the problem earlier today, but we're pretty sure this has something to do with spraying that crap on the MAF sensor though.

 

Ok, I think you are correct about the MAF.

 

OK, to be sure of the MAF fit, you need to enter the vin here: http://www.toyodiy.com/parts/
Then cross reference the part number.

 

According to the truck VIN, that site says his truck was made in 1997, and has a 5-speed manual transmission. It does not. It's a 1995 automatic. That said, I don't have much confidence in that site, sadly.

 

Okay, if you were me, would you take this most helpful ebay compatible chart for a MAF sensor (referred to as a MAF 'meter' in the parts manual), and interpret it to mean that it would work on both the 2.4L AND the 2.7L? It sure looks that way to me:



It even has a helpful manufacturer part number (it lists that part as a "meter assy" too), which matches the number that I found on the toyodiy.com site where it listed his truck as a 1997... at least it listed the engine as the right size, even if the trans was not, so I figured that's an even better proof. What do you guys think?

 

Before you order the part, remove the MAF sensor and spray it with the cleaner. Let it dry completely, reinstall and test. The MAF sensor has a very thin wire in it that heats up. The air flow that crosses it cools the wire that changes the resistance that the computer sees as air flow. The more air, cooler the wire gets, more fuel is added to the engine.
Oil on the wire will change the resistance enough to cause the engine be out of calibration causing the computer to receive inaccurate information which will lead to a stumbling engine.

 

Yes, he'll likely be doing that before work today. I found some MAF cleaner while out shopping this morning, so hopefully this will do it. I'll make sure he looks this thread over before he digs in to it, and I'll post the results if the cleaning does the trick.

 

It's called the element.