Help, tacoma stumbles and dies after fuel filter change.

I just recently changed the fuel filter and my 2.4L 99 tacoma stumbles and dies.

I changed the fuel filter the hard way and took the intake manifold and plenum off. So I could've left something disconnected but I double checked and it seems everything was on.

I even thought I installed the fuel filter backwards and reversed it (this time doing it the easy way through the inside fender area) , still stumbles.

Now I want to ask two questions. What is the right orientation of the fuel filter. Currently I have the "IN" side closer to the fire wall and "OUT" side closer the the front bumper.

Next, can anyone tell me why it stumbles so bad? I know you guys have little information to help me with but feel free to ask questions. I am in a inconvenient spot right now. I actually did all this at my friends house, he lives like 30 miles away from me. He drove me back home and he is going to pick me up tomorrow morning so we can diagnose it all day tomorrow. Any advice will be greatly appreciated.

 

Intake manifold leak? or air leak at another place?

 

Did you use new intake gaskets or reuse the old ones?

And what torque value did you tighten the intake bolts to?

 

I think you have it on backwards.

IIRC on my 2.7 the "in" side was oriented towards the front of the truck.

Dont take my word for it though, I need to go home and look at it first.

 

make sure orientation is correct...but sounds kinda like a vacuum leak of sorts.

 

Okay so I went to my friends house today where my car is and started to diagnose. I found out my fuel filter was on backwards so I reversed it once again. Now the fuel filter is correct.

I used new oem gaskets on everything. throttle body gasket, intake manifold gasket, plenum gasket. I torqued the manifold to engine 13 ft lbs, I torqued the plenum to intake manifold gasket to 22 ft lbs. I pretty much used toyota torque specs for everything. Still stumbling. We pretty much double check the vacuum lines, seems to be no leaks. We actually went back to the manifold bolts and nuts and went half a turn extra to make sure there where no leaks (I know we shouldn't of done this but I worked on a nissan frontier where we had to overtorque to stop some leaks also we kinda desperate).

My friend and I where stumped so we just sat on the lawn smoking cigarettes and talking. I decided to use my codereader and got p0300-0304 codes which where misfire codes. For some reason we decided to clean the corrosion on the battery terminals and when I got into the car the codes erased. I guess we had a reason haha we where stumped and we had nothing better to do than clean battery terminals haha. Not too big of deal I guess, I thought the codes would reappear.

The stumbling occurs only when idling. When I am driving on the freeway no traffic, It runs smooth. I decided to just call it quits and drive back home. While I was driving home I got a check engine light and I decided to stop by McDonalds and buy a bigmac. Before I went in to get some grub, I checked the codes. I thought I was gonna get the misfire codes but I got something else this time P0171. I ate my food and drove back home and checked the codes once again before stepping inside my house. Again p0171 - system too lean bank 1. What happened to my misfire codes?

I'm starting to think it is the IACV. I will be resting on sunday and I will resume diagnosis on monday, starting with the IACV.

EDIT

Just want to explain. Before the fuel filter change, my car was running great. Sometimes there was slight delay on the gas pedal from a complete stop on a cold engine. I forgot code number but I got a throttle position sensor code and I changed it a week ago. After I changed the TPS sensor nothing change, I erased the code and the code never came back. "slight delay on gas pedal fraom a complete stop on a cold engine" was still there. For some reason I decided to have another DIY session and change the fuel filter. I took a look at the location of the fuel filter last time I worked on the car and bought all the gaskets because I thought I had to take the manifold off to get to it. I later found out that the fuel filter was accessible through the inside fender area, but at that point it was too late. Only if I new about the easy way to change the fuel filter, maybe all of this wouldn't of happened? Its just seems weird because it seems every connector and vacuum line is back in place and car is acting up on me.

This reminds me of a time where I was diagnosing a nissan because the inside cluster lights weren't working and it had some catalyst codes. As soon as we started the car there was a loud noise, I forgot if it was grinding or squealing or a mixture of both but the harmonic balancer broke and it was fine until we cranked the car haha.

 

You did all that work might as well change out the Mass Air Flow sensor, and that will take care of your P0171 code.

 

Any chance you figured out your problem? Mine is sort of doing the same thing. a couple times while driving down the road it has acted like it was going to die, just at random then the other day while idling it actually died 3 times. When I rev it up it cuts out. I've changed the spark plugs and the fuel filter and put injector cleaner in it but nothing worked. I took it to a mechanic and of coarse it never acted up and they couldn't find the problem. They said they checked several things including the electrical and ignition coil. ????

 

A crank or cam position sensor is definitely suspect. Especially if it's very random with no codes, and you have not had any serious work done recently like the OP.

 

sorry for not updating. I just couldn't update because I am very busy and was very unlucky also tired haha. I said I was going to update after I clean the IACV but couldn't because I didn't have the chance too. I tried though.

Read my story if you are bored and have nothign to do. Its long and not informational.

Part(One) I started to take out the airbox and other small bolts to get to the throttle body. Seems like I lost my 12mm socket, couldn't find it anywhere. So I went to sears to buy the socket (closest one like 7miles away). I went during valentines day and the traffic was a b1tch to just get one socket, sears was inside mall. I come back take the throttle body off and I try to use my phillips head screwdriver to take the IACV off. The IACV is on the bottom of the throttle body help together by fasteners with a round phillips head. I don't live in my dads house (who has some tools) and personally I have a shitty small collection of tools. I try to take the screws off and I'm turning the screwdriver but the screw isn't turning, screw is on there really tight. Found out I was turning the handle but the shaft of the screwdriver wasn't turning. I didn't want to go back to sears to get a screwdriver so I called it quits on that day.

Part (Two) From now on I told myself I'm only gonna buy quality tools. I failed at school and want to be a mechanic for a living. So I bought a Wera screwdriver set online for like 30 bucks thought it was a good deal. While I was waiting for the screw drivers to come I needed to buy another throttle body gasket. The one I just replaced already cracked. The toyota oem ones crack very easily. I didn't want take it apart and clean the iacv put it back together and find I have an intake leak so I started to look for a TB gasket. I called like 5-7 different places and they said they were out of stock and it is not in their nearby warehouses. I got anywhere from 3-8 business days to whoever I was talking to.

Part (Three) Sorry I didn't keep track of time. I don't know when it was but I finally found a throttle body and my screwdrivers came. I went to take it all apart and clean the IACV for good. I take the throttle body off and use my new screwdriver(it is awesome grips good) and try to take the round head phillips fastener off, there is 4 of them. I take two of them off and they where on real tight. The other two I just completely stripped the inside of the phillips head off with my screwdriver. I didn't even turn that hard. I was like wow this really sucks. I tried using a channel lock holding it the tightest I can and twisting it on the side of the round head. No dice... (( Nothing was going to happen today so I put everything back together.

Part(Four) I already have alot going on during the weekdays and I just didn't want to deal with the problem right now. I was frustrated and decided to just drive the car and fix the idle problem later. I seriously drive like 95% highway so it wasn't that big of a deal driving the car. the frustrating part just came when fixing it. I had another DIY day unrelated to this problem. I installed the kyb gas adjust shock absorbers. changed my drive belts, and decided to adjust the rear drum brakes. I had mushy pedal and I felt the rear drum weren't engaging properly. I spin the rear wheel and it goes 4 revolution. I take it apart and seems like there is alot of dirt build up on the starwheel. I heard it suppose to adjust automatically but maybe the dirt is stopping it from adjusting by itself??? Anyways I properly adjust them till there is only one revolution when spinning the rear wheel with full strength. While I was doing this I found out I had SEVERE cupping wear and my inside shoulder of my tires was completely gone. metal lining showing. So I had to spend all the cash I had and got a pair of rear tires. Hopefully my new shock absorbers will cure the bad toe problem. SOlid rear axle and no adjustability sucks.

Part (Five) Where I stand now. I'm broke. Seems like I have to buy the IACV bolts that are stripped from the dealership. I can't find the bolt size anywhere. Also I don't want to take the TB off again just to compare bolt size. Good news is I think I might get a job as a lube tech. I'm going in for a background check and drug test this week. Its a toyota dealership too !! So ill buy the new IACV bolts there and try to borrow locking plier from a friend and see if I can turn it. I kinda doubt it though. The head of the bolts are super mushy, a little strength will just tear it apart. So my last resort will be take it off the car and go to my friends house during the weekend or whenever he has time to drill the bolts out. I don't have a drill either. I wasn't lieing when I said I was lacking in tools haha.


Yeah ahaha. I didn't forget about this thread. I just had alot of bad luck. I will update once it is fixed though. If the IACV cleaning won't do it, I will continue to update untill I have it fixed.


@jolie hmm thats weird. My problem is always consistent. Idle bad but drives perfect. Funny it didn't act up while you were getting your car checked out. I don't think I can help you yet cause I haven't found out my problem either.

 

3/24/12 update

Been busy got hired lubetech recently and going school with 16 units. I cleaned the IAC really good. replace the damn IAC bolts with a needle nose locking plier i borrowed from my friend. I had to clamp that damn plier extra hard and it finally worked. So after cleaning it and putting it back together, nothing has changed.

However, I picked up some new codes. I haven't pulled codes from the car since last time i picked up the po171.

Here are my new codes
P0100 MAF or VAF A circuit malfunction
P0110 IAT sensor malfunction
and i still have P0171

my oxygen sensor mon, catalyst sensor mon, and evap system monitor read INC on my code reader.

I don't know where to start. I just now know it wasn't a dirty IAC. I'll continue to update and post what worked or didn't work.

EDIT

looks like it might be the MAF

I will test it on wednesday, then replace it if I have to. Damn thing is expensive. 150 for goddamn autozone version.


3/28/12 update. just writing here so I don't keep double posting.

Wow I'm so stupid. So I checked toyota procedures through my auto school. ( I wont say which school so I don't give them a bad name or anything haha). The procedures say to check intake air temperature and see what the temperature is. If it is -40c that means there is a open somewhere and the sensor itself is good. If it is 140c or above there is a short somewhere and the MAF is also good. If the reading is anywhere between, the MAF is bad because the CEL is on with the p0110 code. Normally you would want the temperature in between if there is no code and everything would be good. Because there was a code the MAF would be faulty if it fell in the normal temp range. So I used the scan tool and I found the intake air temperature to be 92F. So I was like damn my MAF is bad it cost $175 for a reman. I double checked the IAT harness wire voltage and it was in range. I read 1.8x volts which was in range of spec. I think spec is .5v-3.5v

Before I get into anything else. Remember on 3/24/12 I cleaned the IAC and pulled codes after cleaning it because idle was still bad. That was the first time I ever saw the p0110 and p0100. The p0171 I had for a while.

Fast forward back to today. Before I went to buy the damn MAF, my instructor asked me if I ever disconnected the MAF because just by disconnecting it while the battery is connected, it trips the CEL to come on. I told him no because I remember resetting the ECU the last time I took it off to clean it. I completely forgot that while I was cleaning the IAC, I had the remove the connector and push the rubber intake hose down, to take off the metal intake pipe, to get to the IAC/throttle body. I mean you don't have to do it this way but I found this way easier.

Basically I set the codes myself by unplugging the MAF without disconnecting the neg cable. Now I am stuck with a reman MAF after letting my perfectly fine OEM MAF go, down $175 dollars, and back to square one. I hate myself right now. Firstly, I should've remember I disconnected the MAF few days ago cleaning the IAC. Secondly, I should've tested the MAF off the car. I just wanted to use the scantool because it was slightly easier to do that. O well... I'll just think of it as a valuable learning experience.

So I only have 1 code that is haunting me, p0171.

I am going to check out the fuel system next.

4/12/2012

I didn't check out the fuel system after talking it over with a friend. I decided to hook up my code reader one last time. I picked up p0171 p0300, p0304 this time. My friend advised me to shoot some carb cleaner to see if I can find a vacuum leak. I was lazy all this time to diagnose it further, not really, just tired to. Today after work I decided to try finding the leak with some MAF cleaner. that was easy less than 10 sec found a leak at the intake manifold gasket. I guess I gotta get another new one again. I'm short on cash maybe i'll go felpro this time.

lol damn I just realized the first reply to this thread was the answer! haha