iamsuperbleeder

So here's what's go'n on; it's easier to show a video than it is to explain...

[YOUTUBE]http://www.youtube.com/watch?v=QFUoC9M3JLc[/YOUTUBE]

If I had a big cam, this might sound awesome! but I dont

Also, it stinks of fuel when running...

At first I though "Ok, it's runing rough, almost like on only 3 cylinders, but it has no power loss on the road; maybe one plugs aren't firing right or something". So I go to each wire and pull it while it's running. The truck idles worse with each, and I can hear the arcing as I move the wires back, so I know it's getting spark. Obviously it's getting fuel, if I can smell it. But to me, it's almost like it's getting too much fuel? To be honest, it use to do the same thing maybe once a week just out of the blue, but it would do it all of maybe 10 seconds, and then it wouldn't do it again for a long time; but this time it hasn't gone away! It didn't do it at first after the exhaust install; it started doing it after I drove up to the store last night, and I noticed it in the parking lot. At the time I didn't think much of it cause like I said, it use to randomly do it and then go away. But it's been doing it since non stop! It accelerates fine, and doesn't jerk or buck while cruising; it only seems to be effecting the idle. No check engine light, so that test wont do me any good. I checked all of my vaccum line visually and by ear, and didn't find anything; about the only thing more I could do with that is to spray some starter fluid around till I hear it smooth out, if it is in fact a leak...

Now the other thing that crossed my mind was the AFM. Now that the motor's opened up with a 3" intake and the header, no cat, and turbo-style muffler, do you think I need to adjust the AFM a little, maybe lean it out some?

I'm at a loss... I can't find anything...

bigt

hrmm i would say o2 sensor but that usually throws a code

toyota4x4907

Dudeo, it sounds sweet, looks sweet (chrome) but it doesnt run sweet...
Maybe you need to adjust the timing since you opened it up some.

My '88 4runner did/does the same thing. It idles like its almost missing on one cylinder, but as soon as I tap the throttle, maybe 100rpm worth, it smooths right out.....then it got a rod knock...

Also, your leafs are really flat

fireman1559

it could be not cause of your recent mods but maybe your cold start injector is stuck on and spraying fuel? hows your gasmileage? can you see any smoke coming out of the exhaust when you drive like black smoke? if so white smoke is to lean,black smoke is to rich and blue smoke is your buring oil. if i were you id go ahead and check your vaccum lines with the starter fluid. then hows your spark plugs when was the last time they were changed and what about fuel filter i kno the filter wont cause it but you never know just start going through what you think it might be and make you a list of things it is not thats all i can help you with im sure abe will be more help than me

jessekosten

I would look at adjusting your afm to match the amount of air the motor can now flow since it has been modified. The other thing to check is your base timing. Any adjustment to air flow can affect it. I can not remember the site I was at but it suggested that anything over 2.5 inches won't have enough back pressure for the low rpm range.

iamsuperbleeder

all the answers sound good guys, thanks! but what get's me is why it was fine for a little while, and then it started...

tomorrow after work I'll pull the plugs and look at them, and I'll spray around with some starting fluid to try and find a leak

I'll play with the timing a little bit too, and see if that effects anything

can't tell on fuel mileage yet; I filled up yesterday (when I went to the store actually ), so we'll have to see how that goes.

I tryed just unplugging the cold-start valve cause I suspected that maybe too, but I guess it could be mechanically stuck open, not that it's got a constant signal to stay open

O2 sensor's maybe a year old as well. my old one didn't throw a code when it went, but it made my mileage go to hell... but it otherwise ran fine...

no smoke that I can see, just the smell...

fuel filter probably doesn't even have 20k on it; plugs maybe have 2k on them ( I changed them right before new-years )

and the mention about the not having enough back pressure with tubing over 2.5", well there's also no cat in the system anymore either ( maybe that's what I'm smelling? ), so I don't know if maybe that would have something to do with it... I wouldn't think so though...

and yes, I know my leafs are SHOT, lmao; that's why the WabFab shackles that are 3.5" longer than stock just leveled the truck out


on another note, after it started doing it, I put in some Z-Max ( the fuel and oil additive stuff; the stuff that's like $40 a kit ) that I had sitt'n on a shelf, but so far that has had no effect on the running ( not that I expected a whole lot ), but it was worth a try

fireman1559

oh i didnt read that you didnt have a cat yea the smell id say a good 80percent of the smell you have is not havein a cat it reeks kinda like gas but not really its hard to explain the smell but its very noticeable. and see my thing is if it was the afm casuin the problem it would have done it when he got finished with the exhaust not a couple of days after. have you checked your TPS?

iamsuperbleeder

it's less than a year old too lol, I tried unplugging it too and seeing what happens; the idle speeds up a little ( maybe 200 RPMs ), but is still rough...

Green93

When I re-did my exhaust I bought a test pipe to install instead of the cat. The truck was loud as hell and would start to give me a headache from the gas smell while sitting in traffic. I just swapped in the stock cat and the smell went away and the exhaust note changed dramatically as well. Now it's nice and deep. I still have plans to order a high flow cat but my test pipe just sits on the workbench.

Jason

fireman1559

that narrows it done more it could be iginition circut,engine coolant temp sensor,fuel pump,fuel pressure regulator,idle air control valve. you could try those and see what you come up with

iamsuperbleeder

yeah I kept my old one; all that I would have to do is cut the pipe that came with the kit a little shorter, and I can bolt it right it place where the header and the rest of the exhaust meets

89whitetoyota

I know in my 2000 GT it took about a day or two before the computer would register a problem after a modification. I dont know if these computers are like that, but ever since my cat was stolen I have had this rough "cam like idle" however after I drive it for a while it smoothes out and it was like there was no problem.

fireman1559

im not sure about the ECMs on these truck on my last one ford when i put mods on the motor and exhaust i had problems if i had problems right after i put them on i did custom headers and no muffler out the back and with no muffler not as much backpressure so when i let off the gas i heard pops in the exhaust yea the PCM didnt like that i think i went about 3 or 4 miles and the PCM shut more than half the power to the motor becuase it went into a safe mode is what the ford stealership called it

iamsuperbleeder

I know Fords are picky about that... when I put an X pipe in my Mustang, it threw all kinda codes... drove me nuts... I just kept having the light turned off with an OBDII scanner, lol, ran like a raped ape though

I think the ECM's in these trucks are a little primitive to have that kind of programming though... but I've been prooved wrong before...

fireman1559

like i said not to sure with these truck ive been wrong before too but from what i have read about them the ECMs are pretty good considering how old they are and when they were made my opion of course

iamsuperbleeder

holy crap I just thought of something...

there's a good chance the truck's been doing it from the moment I installed the header and everything...

I say this for one reason; it's only noticable once the engine warms up. While it's still cool and the idle's up, it's not noticable.

After I finished the install I started the truck and ran it all of maybe 2 minutes to check for leaks, which wasn't enough time to get to full operating temp. Then when I took it to the store it had plenty of time to heat up, and that's when it started doing it.

Also, the stench from the exhaust may not be a gas smell from too much gas. It's more than likely just because there's no longer a cat in the system.

I think I have some AFM adjusting to do...

but I'm going to try all the little stuff first and see how that works

Jay351

Pull the battery cables for an hour. Reset the computer let it learn...

I had to do that when I did my cams..

iamsuperbleeder

hmmmm, now there's a good Idear too! Thanks Jay, I'll give that a whirl!

Jay351

No problem! I hope thats the problem

I need to figure out why my truck is running rich

iamsuperbleeder

lol, that would be awesome if that's all it is!

cross yer fingers!