Help! problem with 01 sr5!

[aliciah04]

okay..i'm new here! and i need a little help about trouble shooting the problem i'm having with my fiance's 01 t4r.

let me give you a little backround info.. & what we've done already to try and fix this. here goes!


about two months ago, we were on the freeway and the check engine, vsc trac, and trac control lights all popped up.

it happened fairly quickly..so we assumed it was just a small glitch. reset the battery..and it did it again.

we used an obd scanner and i dont know the exact code that came up, but it told us that the" fuel system was too lean". which from the information i've gathered means that there is not enough fuel to oxygen..correct?

a few people mentioned that it was the o2 sensor - we checked prices at the toyota dealer near our house, and they said that california vehicles are equipped with an "air fuel ratio sensor" and that its BEFORE the cat.. which ended up costing $222.00, but didnt fix the problem.

we also replaced the sparkplugs, and the fuel filter...still didnt fix it.

the symptoms that are causing concern are :
hestiation and stumbling during acceleration - when you step on the gas pedal all the way to the floor..theres hardly any power. it seems like it takes forever for the car to get out of its own way.
when you step on it half-way, it accelerates okay, but not up to par.
knocking and pinging & backfiring.


thanks for any help any of you can offer..hopefully we can fix this soon. its too good of a car to be running like crap!

 

[96dcmss]

Sounds like the Mass Air Flow sensor to me. Take out the MAF and look at the tiny sensor wires. If they are all white and fuzzy looking, replace the MAF. If you want to confirm this use some cleaner to clean off some of the gunk and you should notice an instant difference in your hesitation and pinging. Common problem on those truck when they get some age/miles on them.

When this happens to the MAF, you don't get a "MAF" code, but a lean condition. The MAF is still connected(ie: no open in the circuit), so the PCM doesn't know, and will just adjust air/fuel ratio to what it is reading.....which is inaccurate if it has carbon build up all over the sensor.

Hope this helps, let me know what you find out.

 

[aliciah04]

just looked at the wires on the maf and they seem fine no white fuzzy stuff but the diode on the end of those wires is a pretty dark transparent brown. is that normal? and also do you know what the ect button stands for? i would hate to spend more money on the car and come to find out that it didnt fix the problem. someone told us that it was the maf sensor before and i took it out and cleaned it. it had black crud all over it. put it back in and still the same problem.

 

[wolfgang]

ECT - electronically controlled transmission. Gives more performance (less gas MPG) by holding gear to higher RPM before shifting. Sounds like it is undriveable as it is - take it in and have it diagnosed properly - 2 folks saying bad MAF would make me swap it out though. How did you clean it - contact cleaner I hope. It is fragile.

When you cleaned the MAF did you also clean the throttle body? It gets black and grease and cloughs up too. They have special cleaner or you can use spray carb cleaner. Thinks like air filter and plugs are normal maintenance items so don't count them toward cost to fix.

 

[96dcmss]

nine times out of ten it's the MAF with the symptoms you're describing. If you want to be sure, take it to the dealer, they will most likely charge you a half hour, and quote you a new MAF. Sometimes it's cheaper to pay a tech to diagnose it then to throw expensive parts at it. Just my .02.....

If you want you can check it over for vacuum leaks as well. If you don't find any vacuum leaks, my money is on the MAF. Re-check it for codes if you can....make sure you don't have a specific cylinder misfire code.....you may get a random miss if it gets lean enough though(P0300). Can't think of anything else to check, you already did the fuel filter......still won't hurt to check fuel pressure though.

If all that is there is lean, it's most likely going to be the MAF.......but as I said above, the closest thing you can get to a guarantee is to pay a professional to diagnose the truck.

Good Luck, and let us know what happens.:

 

[4rnr4me]

its the MAF! mine said the exact same thing, and thats what it was...I cleaned it and wa-lah all better

what did you clean yours with?

 

[aliciah04]

okay so i bought the crc maf sensor cleaner and cleaned it still no results. i think its time to take it in and have it diagnosed the right way.
next question what can i put under my hood scoop???????

 

[thrak]

It could be the TPS... if its not sending out the proper voltage to the ECU for the amt the throttle is opened, it would cause it to dump too much or too little fuel...

TPS's are easy to check and cheap to replace.

 

[wolfgang]

"next question what can i put under my hood scoop???????"

Knight Rider (KITT) led lights will improve your zero to 60 times. Not enought room for a pizza oven.

 

[aliciah04]

oh there is plenty of room just want to put something to improve horse power or maybe give me better gas mileage. how much would the tps run me?

 

[seanyc]

This just happened to me. i also have a 01 4x4.

At first I was PO'd. I had just left a valet parking garage in downtown SF and a mile down the road I noticed the VSC and Engine lights on. My initial thought was they were really trying to roast the tires in the garage ... grrrrrr.

I followed the advise on one of the post here to disconnect the negative terminal and pull out the ECU fuse. some here say its 15amp, mine was 20 ... and labled 20 on the fuse box diagram.

I waited an hour to make sure the capacitors were fully drained, reconnected and started, no more lights on.

Oh and just to point out, when the lights were on VSC was in fact disabled.

hope this helps.