Ok this is really puzzling me. First thing in the morning when I'm about to leave to work I start the truck(01 tacoma) and it fires up and idles fine. Whether I get in right away or let it warm up for a good 5-10 mins it misses bad when I give it gas. I mean bad, i have to let off the throttle because it makes it seem like i'm hitting a 2000K rev limiter. SO I baby it until it reaches normal operating temps. then it gets better(but still there) After I give it some firm throttle pressure and get it to kick down to 2nd it accelerates up like normal and the problems gone. When I said it does this even when i let it warm up in the driveway I mean just not as long, when i get moving and hit the gas it goes away. Here's the wierdest thing, it will never! and I mean never do it the rest of the day, no matter how long it sits and cools. So the only thing different is that it sat over night, so I figure it has something to do with condensation forming somewhere and so it runs funny till it dries out. I just can't figure out where, if that is it. I've gone through the intake, cleaned the throttle body, and am going to pull the plugs tomorrow just for the hell of it. It doesn't get that cold here in So Cal, but whether a rainy or frosty morning it misses like you wouldn't believe.

Has anyone ever had a similar problem? Maybe condensation in the fuel system? That was another thing I thought of, and I have installed a body lift and figured maybe a loose line. The only reason I dismissed that was it still holds pressure. Anyone know how long it should though. Then maybe I could let it run, kill it, wait a certain time and then pull the gas cap and see if it's still pressurized. If it's not see how long it does hold pressure.

Does this sound right, the only thing I can think of is water in the system, i mean thats how it acts. Though it does hesitates bad, it still idles fine.

 

its supercharged, correct?

 

Ah totally forgot to mention that. No it's not on yet. Have it but am waiting to get the money for the fuel upgrade and the tranny work( valve body and torque converter) first. I felt it was a good idea considering the way I drive, so for now i'll paciently wait. So no it's still N/A, just got this name so I didn't have to change it later.

PLus I didn't want to put the blower on till I knew it was running right. There was one more thing it does, it acts like it want to pull a lot of timing from around 3200 to 4300 only in 1st gear at 70ish and above throttle. It revs up feels like it slows down for about 1000 RPM's then pushes you back in the seat again. But only in 1st, but not only at WOT any time you're heavy on the pedal. You careally feel it, it act's like it's pinging and pulling massive timing. I can't hear any knocking, but might still be there. Any ideas? Does anyone else think that it's retarding the timing for some reason?

 

whew... you were about to get the wrath of Gawd from a few folks if it were.

So... Condensation's a good thought, but being that you're in Bakersfield, that may not be a major problem.

I'd start with the normal stuff to eliminate suspects... Fuel filter, bad tank of gas, plugs, clogged intake (any chance you did the ISR mod?), TPS. Possibly a clogged exhale path (cat, muffler)...

How many miles are on the engine?

Your thoughts on a loose vacuum line are valid, but not if the problem corrects itself - that would be a bit weird.

 

the only thing i have to offer is to try a seafoam treatment.. search seafoam for more info if you are in the dark about it.. if it doesnt fix your problem, youll at least have clean insides...use good gas too..

 

just over 50K on the miles. I still have a lot of dew and frost in the morning. It's getting into the 30's here overnight now, so thats why i figured water. I've been thinking of changing the fuel filter, I may as well to see, but like I said it's only in the AM. The rest of the day it runs perfect, except for the funny 1st gear hesitating. I've also run chem tool injector cleaner and such through the tank and noticed no difference. I've been running 91 now also, and was going to run sea foam this week but it's tough to find here. I found some so I'll go pick it up tomorrow.

 

Also on the ISR mod, I don't have a silencer inline. I've looked at all the giudes for the ISR and none of them look like mine. All I have is that tiny box off to the side that tees off the the intake tube. It's hollow, I was under the impresion it was just kinda like a vaccum resivoir. I've also changed the intake by taking out the airbox and putting a cone on. The reason behind this was second battery where airbox sat. But this shouldn't make it run funny, jsut better. It still has the MAF just with more air flow. I also cleaned the MAF, the probe was covered in crud.

 

The temp differential could be creating condensation, but if the tank is full, then there won't be enough to cause something like this. The ethanol in the fuel will take care of most anything that shows up in a full tank. Now, it'd be more of a problem if you had very little fuel in the tank. Condensation in the lines would be gone pretty quick, so that's probably not the problem spot.

Changing the fuel filter is a good idea anyway... But I agree that since it's only happening in the AM, that this isn't a huge suspect.

Regarding 91 octane... Unless you're running a S/C or have done something to require a slower burning fuel, you really don't need to spend the $$$ on that fuel.

Seafoam will help in general, but this sounds like something else going on.

You mentioned that you were gonna pull the plugs today - how'd they look? The color and garbage collection on a plug can tell you a LOT. Post a pic of _all_ the plugs if you can.



Okay, so... you replaced the airbox with something like a K&N cone, right? But the silencer is still there? (I'm just trying to get a clear picture of how you're running)

And when you cleaned the MAF, are you sure you got everything out of it? Which process and what chemical did you use to clean it?

 

Another thought...

When you say "crud", was it road grime or had you been out playing in the mud?

It can be worthwhile to pull the intake apart from the cone to the throttle body and clean it all out. Clean the TB as well.

Gut feel right now is one or more fouled plugs... Easily fixable, but then, it'll be important to try to find just how the plugs got fouled so that it doesn't happen again.

 

Ok I started with the #5 plug since it was easiest to get to. It looked perfect, just the right shade of brown. No signs of running rich or lean.


I may have found the problem. The truck ran perfect this morning, but I didn't start it till noon when it was sunny and dry. I noticed some corrotion on one of the ignitor wires. Ok here's the story. At pismo an old filter i had rubbed on the ignitor harness and and rubbed the far right wire raw. When it touched it it did just what it does now, pre ignite or miss. Well i called toyota to get some of the metal connectors that go into the harness and just shorten the wires a few mm. They told me they can't get those individual parts, they would have to get a whole new wiring harness. So I made due and cut a section out and put in another piece of wire. Well the two wires next to that one were showing and had corrosion on them. I assume they were getting bridged or shorted by water so I sealed them with electronic safe gasket maker. We'll see if it happens again.

Ok now for the intake, heres a pic below. I don't have the silencer it shows in the guide. All I have is a little airbox. I was going to take that off but need somewhere to put the 2 air lines first. Does anyone know the purpose of these lines or are they just some type of breather or return.

 

The crud on the MAF was road grime, and I've allready cleaned the whole intake and cleaned the throttle body very good with TB cleaner. I'm going to pull a few more plugs and see if any are fouled.

 

Well the rest of the plugs look the same. It's running perfect now, I'm guessing the lack of power in 1st has something to do with the air/fuel and just the stock mapping i guess. I'm going to put the 5.29's in this month. Then the blower with more fuel should cure any hesitation there is.

 

Cool. It sounds VERY probable!


That "little airbox" _is_ a silencer. It reduces the intake noise by way of forcing the incoming air to swirl and fill the box before heading to the TB.

You should be able to trace one of the lines down to the power steering pump. There's another one from the pump that goes to a fitting on the "downwind" side of the TB. When the pressure difference between the two lines hits a certain threshold, it will open a switch on the PS pump to allow more fluid pressure in the steering rack which will make it "easier" to steer.

The other one is probably heading to the FPR which terminates in a brass tube at the front of the block, just in front of the TB. This is a tap that allows more fuel pressure as the vacuum increases in the intake tube. More vacuum means you're sucking more air, and the pressure hasn't equalized, which means your right foot is in the carpet.

But, with the removal of the airbox then it may also be T'd and heading to your EVAP canister (black box with two humps on the driver's side fender well). That's a return breather and is an emissions feature.


If you move the lines, you can pretty much put them anywhere along the intake tube path, as along as it's in front of the TB. Check this writeup on the ISR removal for a '96 and note how one of the end caps gets drilled for a couple of hose barbs.