fourplayoffroad

Hello I have an 85 runner 22RE that is hard starting when 40 or below also not much power, poor fuel milage (around 15mpg), and sounds like a rev limiter is coming on at 3,000- 3,300 RPM or it may just be popping or backfiring through the intake. I was told it was back fireing through the intake because of a lean condition but not sure if thats true. when I bought the truck it had a check engine light on for MAF sensor, O2 sensor and EGR valve I have replaced both sensors and disconected the EGR valve and plugged it but with no change. You can here it really well if under the hood and reving it up. I already know that my cold start injector isn't getting power to it but not sure why maybe the cold start timer switch?? would it cause all of these problems I put a used one in and still same problem but then again I could have gotten a bad used one and a new one is $183 at the dealer I've checked around but cant find one anywhere else and I also dont want to just keep dumping money into it for no reason. Any help would be much appreciated.

Thanks
Mike

myyota

If the cold start injector isn`t working that will make your 4Runner hard to start, pull the cold start injector out of the upper intake and clean it, sometimes they get covered in carbon and that can keep them from working. If your thermal time switch is bad you can get a new one from www.partstrain.com for 150.00 dollars. If you have a pic n pull around were you live check there for one. If the 02 sensor is original or very old then you should replace it, if its bad it will effect your gas mileage. Replace the 02 sensor with a Denso 02 sensor, don`t use a bosch 02 sensor, they don`t work well in toyota`s. Also replace the fuel filter if it hasn`t been done in a long time. The rubber elbow that connects to the throttle body can crack from age, so check it and replace it if its bad.

fourplayoffroad

When i rebuilt the engine a year ago i cleaned all the injectors including the cold start the problem with it is that there isn't any power going to it at the plug. I replaced the o2 sensor but it was a bosch that i put in does it really matter what brand? I checked to make sure it was working with my fluke multi meter and from what i could tell it was but i still had a check engine code for it. Same thing with the maf sensor i put a known good one in bit still have a code for it. Tonight i messed with the timing some and also what i believe is the air mixture or idle air screw it's the one on the top left of the throttle body and by doing this it doesn't "pop" through the intake when under the hood and reving it but when i took it out a drove it, it still "popped" through the intake but it seemed to have a slight increase in power but nothing significant. Is there a way to know that i have that air screw set right? Or am i off track even messing with that And the timing?

myyota

Most people here that have used a Bosch 02 sensors in there toyota`s have nothing but trouble with them, that`s why a Denso 02 sensor is recommended (its an OEM replacement). The screw you messed with on the throttle body is used to adjust the idle, that`s all it does. Another thing you might check is the TPS, make sure its good and that its adjusted properly.

fourplayoffroad

Intake tube has already been replaced no leaks.
plugs were done about 2 months ago I replaced them with NGK and did the proper gap.
It's not a mid-high rpm "sputter" its deffinetly a backfire.
someone told me that the cold start injector also sprays fuel when accelerating or WOT is this true?? I dont remember it doing this at the very begining of summer and I really havent changed anything on the engine.

fourplayoffroad

So i went to a buddys tonight and swapped the following with known good parts from his truck : AFM, coil/igniter assy., ECM, and the distributor..nothing changes by swapping these parts. Still popping/backfiring through the intake around 3000-3300 and only when driving it if it is sitting and you rev it up it doesn't seem to do it???? Im not sure where to go from here suggestions are greatly appreciated

myyota

Are you sure the timing is set right ?. Above you said that you cleaned the injectors about a year ago, did you send them out and have them cleaned or what ?. If your friends truck has a stock Denso 02 sensor swap it on to your truck and see if it makes a difference. Check the rubber intake hose that connects to the throttle body for cracks, if that elbow is cracked it will let un-metered air into the engine causing a lean miss.

fourplayoffroad

pretty sure timing is set right I jumped it at the plug then set the timing to 5 BTDC.
I sent the head along with intake and injectors etc.. to the machine shop to have them clean and check the parts for me. The intake was extremely carboned up and the head ended up having some cracks so I bought a new head and rebuilt the engine.
Not sure what o2 sensor he has but I wil check.
The rubber boots for the intake are good no cracks I even put his on just to be sure.
it only seems to backfire through the intake when its under a load ( driving it ) if it's just sitting and I rev it up it doesn't seem to do it. I haven't tried the fuel filter yet could it possibly cause this or maybe the fuel pump getting weak??

myyota

A plugged fuel filter can cause a lean condition at higher rpm`s because its not able to flow enough fuel through it. Change the fuel and see if anything changes.

fourplayoffroad

changed the fuel filter but the truck still runs the same...

fourplayoffroad

It ended up being a flat cam EXTREMLY FLAT!!! 2 lobes didnt even have any lift they were round.. im going to be taking the cam and rocker assy. Back to the machine they only have around 9,000 miles on them

myyota

It seems like a lot of people are having problems with cams lately.