sputtering problems need help!

[wolfjm82]

Trying to figure out whats wrong with this without hooking it up to a computer

its a 95 3.4, wasnt driven in 3 years, started it occassionally it has never had problems, only has 70,000 miles on it

this past winter I bought one of those ebay intakes to replace the existing filter box and intake duct

there is a small tube that goes off the back of the stock intake duct after the air filter and runs down to a small box with a bunch of other tubes (vacuum?)

well the intake I put on it, didnt have a place to hook that tube into the new intake so I just let it hang there freely sucking in air

after taking it for the first drive this spring it sputtered, check engine light came on and would sputter and then kick out of it and would keep doing it on and off, now its doing it all the time when driving, when I just start it up and let it idle, it idles high at about 3 before it was at 1 or a little below before i put this new intake on it

also after putting the new intake on it i noticed it would have a slight knock about every minute or 2, when facing the engine it comes from the right side but cant figure out where that comes from, i figured maybe the intake messed up something with the vacuum system and/or was messing with the fuel/air ratio so i put back the stock intake on it and hooked that tube back up to the back of the intake duct, i unhooked the battery to reset the computer but am still having the problem,

i checked all the plugs/wires and they are all attached

sometimes when coming to a stop it will stall out

ive put dry gas in it also to make sure there was no water in the gas and that didnt help either

looking for any suggestions, and also does anyone know what that little box is that sits below the intake duct and has a bunch of tubes coming out? couldnt find anything about it in chiltons, could that knock be from spark knock? and would replacing the sensor be the trick? trying not to run it too much incase its damaging piston and/or head gasket...also the check engine light is on constantly now

[2K3800CAMARO]

Re: sputtering problems need help!

If the car stood that long and was never really driven much , you might wanna concider cleaning your injectors

[vanbibber]

Re: sputtering problems need help!

the hose youre talking about is the AIR pump hose. its emissions crap.

have you checked fuel pressure? could be the fuel pump going out or the fuel filter could be clogged.

im not sure what youre talking about with the box with tubes on it. im guessing its probably the AIR pump. cant remember for sure since i dont have a 3.4 anymore.

other things you might want to check are the coil packs, icm, and the PCV valve.

[wolfjm82]

Re: sputtering problems need help!

ok so after letting it run for about an hour with the stock intake back on it the knock has completely gone away and sounds a lot better, the sputtering is still there though, and the SES light comes on and off still,

I have no clue how long its been or if the fuel filter has ever been replaced, this is the only car ive ever worked on so i dont know a lot about testing things,

what do you need to check the fuel pressure? would that check the pump and the filter and how would you determine which of those it was? and whats the easiest way to test plugs and wires?

oh and another thing started just recently, the oil pressure gauge is very slightly twitching, if you hadnt seen how smooth it moved before then wouldnt notice but i noticed it slightly twitching at idle and when giving it some gas...almost cant even notice it its so slight...

thanks for replying back so quick :-)

[vanbibber]

Re: sputtering problems need help!

go to the parts store and pick up a haynes manual. the parts store can scan the car also (autozone and advance should be able to.)

keep in mind though that the only way you'll find out what the code is, is if the ses light is on since its a 3.4 and they are OBD1 and will only show the codes when the service engine light is on.

[Nikos95]

Re: sputtering problems need help!

Simple things make all the difference, I just bought my 95 3.4 after it sat for about a year and a half. Same issues for the most part.

I dropped and cleaned the gas tank out, changed fuel and air filters, changed oil filter, did new plugs, wires. Filled her up with new gas and ran a few cans of Seafoam through it, a bottle of marvel mystery on my last oil change to help clear a noisey lifter, a tranny flush and fill, and a new thermistat.

Still need new o2 sensors, iat sensor, and ignition coils. I think I'm going to have to rip my lifters out, they arn't shutting up...

But after all that mine about shut up, and runs smooth now and it has 140k+ on it now. In the last few months I have packed almost 8k miles on it, after 4k on the oil, it comes out nice and clean still :)

Soon to come a complete rebuild anyways.


there is a small tube that goes off the back of the stock intake duct after the air filter and runs down to a small box with a bunch of other tubes (vacuum?)

Are you talking about the Breather tube? If its that it should connect to the rubber elbow right before the IAT sensor.

[wolfjm82]

Re: sputtering problems need help!

ok next step I guess, I pulled the whole throttle right off and cleaned it all out with carb cleaner, a lot of nasty black stuff was oozing right out of it, replaced the gasket put that back on

changed the air filter, it already has new oil and filter on it, and today I just changed the fuel filter (never had a gas bath before so that was interesting) anways

the problem is still there.....where should I go from there spark plugs and wires?

still idles high sometimes but others goes back down, SES light still on and still having hesitation when driving but not during idle and also that little pop has returned when facing the engine its on the right side lower of the engine....

also is it normal to hear a pop noise come from the air box in which the filter is in? I flicked the throttle real quick and a pop sound came from the box...

also is it possible for something like a mouse to crawl way up into the cat and would that cause problems like this?

[wolfjm82]

Re: sputtering problems need help!

also I ran some chevron techron injector cleaner through it.....

[vanbibber]

Re: sputtering problems need help!

is it backfireing through the intake? if so id say you have an issue with the rocker arms needing to be readjusted. pull the air intake off and see if it backfires through the intake manifold and throttle body. just throwing that out there becuase when i didnt have my rocker arms spec'd right on my lt1 it did that. but i doubt its that.

try spark plugs and wires first. and check all the vaccume hoses you could have one not connected or loose somewhere..

[vanbibber]

Re: sputtering problems need help!

and damnit. go to autozone and get them to scan it. it will tell you what the problem is. its free

[Nikos95]

Re: sputtering problems need help!

If your dead sure its backfiring you need to get that fixed.

But as a funny one here, I though my motor was backfiring if I gave it a kick right as I started it, and turns out it was my motor jumping because of broken motor mounts.

[wolfjm82]

Re: sputtering problems need help!

yea not sure whats wrong with it :-S so I guess Im going to have to take it and get it checked, problem is we don't have autozone up here only napa, vip, and carquest and I asked all 3 already and none would do it for free, tommorow i will see if this local shop down the street will hook it up for 5 bucks or something....sucks also the driving is sooo erratic on it, its almost impossible to get anywhere without accidents especially in traffick, car all jerky...gonna have to use a trailor to bring it down....

[Mike88]

Re: sputtering problems need help!

The first thing that jumps out at me is that the car sat for 3 years. A number of years ago I bought a mitsubishi Mirage as a beater and it too had sat for an extended period without having been driven much. The guy had been trying to sell it for a number of months, parking it on the corner during the day and back into his garage at night. The problem was that he didn`t have much gas in the tank and the temperature change between outside and inside twice a day caused condensation on the inside of the tank. It didn`t take long before the inside of the tank was covered with a layer of surface rust. I had so many problems with the car in the couple of months after having bought it. I had to clean my injectors on a regular basis, change my fuel filter a couple times, and change the fuel pump twice. If you do have rust in your tank because the car sat for so long under similar conditions to my crappy beater, then you have to change the gas tank. I`m not saying this is your problem but it`s a good start.
PS. 'rusty gas tank' won't show up as a code at any autoshop. It will throw a couple of the codes that result from the kind of thing you have described. I'd consider the possibility, otherwise you can keep 'fixing' the problem and having it reoccur a couple of weeks later.

[CDNFB]

Re: sputtering problems need help!

Sound like one of your ignition coils is crapping out. But retrieve that code first!

[slow6]

Re: sputtering problems need help!

The problem was that he didn`t have much gas in the tank and the temperature change between outside and inside twice a day caused condensation on the inside of the tank.

probably had created condensation in the oil too which turns into acids that eat at the internals