tpastorok

So i upgraded from the stock single snorkel air filter to an open element and I'm having bad problems now. I'm pretty sure it's just that the air:fuel ratio is messed up but I don't know how to fix this. I took it on a long test drive yesterday and eventually it straightened out and I thought it just needed to adapt and it was all set. But this morning I took it to school and half way there it got really bad again. Is there a way I can set the injectors to give more fuel to balance out the air? It's a 91 camaro rs 305 tbi

khulsebus

iTrader: (2)

Did you install the inlet air temperature sensor in the new air cleaner?

tpastorok

Ohhhh no I didn't do that, is that the only wire that went into the old filter?

khulsebus

iTrader: (2)

The short answer is yes, it was the only pair of wires that connected to the air cleaner.

The long answer is..... There should have been a two wire connector that connected on the bottom of the original air cleaner, and a vacuum line on the other side. The vacuum line was for the heater valve in the snorkel, not important. Only heated the air in the intake to warm the engine up quicker, and then closed once the car was warm. The two wire connector gives the computer a signal to tell it what temperature the intake air is. Without it, the computer is going to take a, as you said, long drive to correct it going pretty much only off of the o2 sensor.

tpastorok

Yea I knew the vacuum lines are okay to not have but I thought I figured those wires didn't matter either, because I put the old filter back on without hooking anything up to it to test just that and it ran fine but I didn't push the engine very much, so I guess it matters a lot more when the engine is taking in hotter air?

khulsebus

iTrader: (2)

Yes and no. It will be more noticeable with the engine taking in more although hotter air.

If it were my car, I would try and get my hands on a L69 air cleaner. The wider twin snorkel piece, even though they are rather expensive sometimes they come up for a reasonable price with the plastics. I would also raise the sides up a bit in order to fit a taller air filter and remove the air valves from the snorkels, but leave them externally. Paint the whole base assembly in flat black, and only the resto guys would notice the difference. Or put a cowl hood on it with some kind of pan under the carb/TBI unit. But my car has other issues with the air filter getting cold air.

tpastorok

Update:

I got home and installed the IAT just as it was on the old filter, and the problem seemed to be fixed. I drove around for a little, and then I had to go in somewhere for about an hour and when I came back out I started the car and it shook and stalled. Started it again, it surged a little and was doing exactly what it was doing before. But i let it sit for probably only a minute or two and it pretty abruptly went back to normal and drove home perfectly fine. Its not a huge problem but its obviously not right, any ideas?

tpastorok

This morning it was back to being just as bad as no sensor, my guess is the sensor is going bad so I'm gonna go to Napa today to get a new one

Schurkey

Why not reinstall the stock air cleaner just as it was, and see if your problems go away? If they do, you know the issue is with the new air cleaner system. If not, you aren't chasing the air cleaner as a problem when the real problem is somewhere else.





I really hate hearing folks claim an open-element air cleaner is an "upgrade". There's about 29 other things a person could change under the hood that would make more of an improvement in the engine's power, and some of them wouldn't have the downsides that the cheap open-element housings do.

tpastorok

Yea if the new sensor doesn't do it then that's what I'm gonna do. And I didn't do it so much for the power, more or less for the nice look and sound. I know there's other things but I'm short on money right now so I've just been looking for little things I can do until i save up. Do you know of any good bang for your buck upgrades I can do?

RS-Chevy-SS

Hate to sound like a broken record, but ensure you don't have any vac leaks, replace the IAT, if problem persists check fuel pressure. May just be a coincidence. Refer to my thread below for similar symptoms. Side note: That's one of the first times RF helped me with the car.

https://www.thirdgen.org/forums/tbi/...ue-pt-3-a.html

deadtrend1

iTrader: (1)

is your new air cleaner sitting right on the iginition coil plug wire and possible arcing? And like said, make sure the vacum line that went to the thermac valve is capped at the base of the throttle body

tpastorok

I know its not touching the coil and i did cap that vacuum from the Throttle body. I didn't get the IAT today but they said they will have it in the morning so i'll post an update tomorrow. Fingers crossed that its just the sensor

Ron U.S.M.C.

This is the one you caped off ?
Mine looks like this
Its the little black cap on the front of the TBI unit =

tpastorok

Yea that's he one I capped off. The spacer i needed came in this morning (didn't replace the IAT yet) and I put that on and took it for a test drive as a shot it in the dark. It was a pretty long drive and i made sure i pushed it at times to get a full range of driving and I had no issues. I far from calling it fixed but is it possible that the spacer could've made difference? The only thing it did was make it clear the linkage better

khulsebus

iTrader: (2)

You should still check for vacuum leaks, the hoses crack with age and you might not even see the leak. Did you put one of the ring spacers between the air cleaner and the TBI unit?

tpastorok

Yea right now i have the stock spacer that is on there and a ring on top of that between the tbi and the filter. And i'll check for vacuum leaks right now

khulsebus

iTrader: (2)

I like using propane to to find vacuum leaks, but there are some other methods.

The ring spacers..... are restricting your airflow. A TBI breathes from the sides instead of straight down like a carburetor, because the injectors are in the way. When I had a TBI car, I did the ultimate TBI mods....
https://www.thirdgen.org/ultimatetbi
https://www.thirdgen.org/ultimatetbi2

My recommendation would be to remove the spacers and clearance (dent) the base to clear the linkage.

tpastorok

Checked for vac leaks and couldn't find any. I'm not too worried about the efficiency of it right now I just wanna get it working first. Once I do that then i may look in to getting rid of the spacers

PATRIOTIC1911

iTrader: (2)

Some times you need to allow your ECM to reset with these types of changes. Allowing the ECM "time to adjust" isn't enough. You need to actually unplug you battery for 30-60 seconds then reconnect. This will cause your ECM to reset.

tpastorok

I've determined that it had nothing to do with changing the air filter, it was just pure coincidence that it happened at exactly the same time. I put the old filter back on and still had the problem so I've moved on to trying other things. Still haven't fixed it though

mauijerky

Exactly!!, even with the IAT unplugged, there should be no major issues that a tbi motor could incur from an open element filter. It would mess with the fuel trim, but not enough to cause chugging or stalling.

Any error codes?

dmccain

iTrader: (2)

Ron U.S.M.C.

You may have done this already but generally speaking if you have a problem right after you touch any part of your engine than that's where to start.

Take off the stock assembly and start looking around the TBI unit. There are some very small plastic vacuum tubes back there that are prone to breakage.

Try to follow them to their destination and make sure they have not slipped off of a nipple or have a poor connection there.

The one going to the MAP sensor is very important. If that slips off or is damaged in anyway you will have trouble.

I bought a small 150 lumen flashlight so I can actually see what I'm looking at.

They have a nice one at Walmart called Ozark Trails 150 lumen for $15.00.

Just another must have tool.