J0hn_J0hn08

iTrader: (2)

91 Camaro RS 305 TBI

Well today i decided to finally take the car in for a diagnostic at the dealership only to find out that they apparently don't work on anything over 10 years old.

So the main guy at the service desk referred me to a local shop few blocks down from the dealership and the place looked pretty legit and all.

Anyway i ended up paying 98$ for the diagnostic and here were my results.



Results:
-Heater hose leaking coolant in the rear of the intake
-Needs new air diverter valve since its pumping air upstream during closed loop operation.
-Engine runs rough, possible weak cylinder.
-Engine is Pinging, Recommended Timing set and Compression Test.
-Burning oil on start up (explains white smoke when i first start car)
-Suggested secondary ignition tune-up

Now i knew about the coolant leak in the back..and expected the whole pinging and cylinder thing also (stock 305 TBI) But the guy said that the air diverter valve is messing with my air fuel ration, making the computer pump in an excessive amount of gas.

Can that really be it? can that seriously cause my car to try to die on start up and force me to give it gas? Half the cars i see here on thirdgen don't even have the diverter valve. Can i just simply remove the whole valve? What would be the effect of doing so, and what is its main function anyway?

As some of you may already know Ive been suffering from

-Car tries to die on start up ( i have to give it gas to get it to stay on)
-Hesitation when accelerating
-Hard Starts

Really im trying to find out if what the man suggested is legit, or if its just an assumption hes making. If it isnt legit then i pretty much wasted 98$ although he did mention he hooked up some sort of device to test the valve.

Can anyone confirm if this sounds correct or bogus? thoughts/opinions welcome.

Base91

iTrader: (1)

The valve diverts air from the AIR pump into the exhaust manifold when the engine is warming up. It helps to complete combustion and reduce 'bad' emissions. When the engine is warm the air should go to the cats or to atmosphere. If it's putting air in the manifold when the engine is warm it'll make the O2 sensor think the engine is running lean so it'll up the amount of gas in the mixture. So it's highly likely it's messing things up but you can't move forward until you fix the things you know are bad. Good luck.

torque_is_good

http://www.amazon.com/Compression-En...8040655&sr=8-7

$25


http://www.amazon.com/Actron-CP7802-...040833&sr=1-10

$15

http://www.amazon.com/Actron-CP7527-...8041004&sr=1-1

$32


http://www.amazon.com/Actron-CP7605-Tachometer-Voltmeter-Analyzer/dp/B00062YUUS/ref=pd_sim_auto_1

$29


All of that comes to a grand total of $101 or $3 more than you paid for an opinion of what it could be. With the above $101 investment, you can narrow it down quite nicely

torque_is_good

http://www.amazon.com/Compression-En...8040655&sr=8-7

$25


http://www.amazon.com/Actron-CP7802-...040833&sr=1-10

$15

http://www.amazon.com/Actron-CP7527-...8041004&sr=1-1

$32


http://www.amazon.com/Actron-CP7605-Tachometer-Voltmeter-Analyzer/dp/B00062YUUS/ref=pd_sim_auto_1


$29


All of that comes to a grand total of $101 or $3 more than you paid for an opinion of what it could be. With the above $101 investment, you can narrow it down quite nicely

So let's review.

Pinging- Stop using cheap gas and use 89 or higher octane. Total cost to you, about a whopping $2 more per week. Or, you could use the timing light and retard the timing (which decreases performance) Also, that cheap gas you've been using could also be the cause for carbon build up which can cause pinging

Weak Cylinder- use the compression guage and you'll know what you have

Burns oil- hmm, is it a ring or is it valve train? Compression gauge will help you examine the cylinders and the vacuum gauge can aid in finding valve train issues

tach/dwell meter- nice to have under the hood when you're working so you can see engine speed.

So, for $101 you could make a post here that says

I did a compression test and found xxxx

My timing is currently set to xxxxx is that correct?

I noticed that my vacuum gauge does not hold steady, i get xxxxx


good luck

J0hn_J0hn08

iTrader: (2)

Thanks for the replies guys, honestly i was just fed up with trying things and the problem persisting. keep in mind ive been at it for quite a while trying to figure this out with just basic knowledge. I almost wasted $ on a fuel pump/regulator trying to troubleshoot.

So this valve is malfunctioning? What causes the diverter valve to go bad? Can i take it out and attempt to clean it? Ive been searching the forums and everyone is talking of about a 250$ expense for a new valve.

What if i just remove it completely would my problem persist? or get worse?

Would higher octane gas really make a difference? I used to pump super all the time but I lost my job and started pumping regular.

Base91

iTrader: (1)

Removing the valve or just blocking it from the manifold would solve that particular problem but it depends on where you live. In the peoples republic of California you can't remove it or block it. I've never had one go bad so I don't know if they are repairable. Junk yard? Rockauto? $250 seems like a lot for a fairly small valve.

torque_is_good

block it off. As for higher octane gas, yes, it does make a difference. Did you know that octane level is allowed to vary by 2 points so 87 could in fact be 85 (or 89). Octane is the ability to resist knock (pinging) and the higher octane, the greater the ability of the fuel to resist detonation.

Anyway, at 10 cents per gallon for 89 vs 87, it might cost you $2 more per week for "insurance"

Sometimes we tend to skimp on things that we shouldn't. It's called penny wise but pound foolish.

Sparkytfl

My air valve was seized up when I got my car. Kept dumping air into the exhaust (EDIT: into the exhaust manifolds. before the oxygen sensor), tricking the oxygen sensor, and it never went into closed loop. Some water must have gotten into it because the valve shaft was crusted over and not sliding, and the spring that was supposed to return it to place if it wasnt stuck had crumbled away. I ended up sawing it open, putting in a new spring, and gluing it back together.

Theres two solenoids on it. Check those first. Remove them, put some hose on, use a nine volt battery to open and close, see if you can suck air through it while open but not while closed.

Then theres the two valves, each controlled by vacuum. See if each one moves when vacuum is applied.

But easiest solution is if you live somewhere that you dont need emissions testing, either remove the valve and put in an elbow from the pump to the cat hose and remove the manifold air hoses, or remove the whole system. Make sure you remove the pump too, not just the belt if you do that, or else water will get in the pump and freeze that up. Took me days to get it open and unfreeze it when it was time for my yearly inspection.

Base91

iTrader: (1)

"yearly inspection"? Sounds like the peoples republic of NY may be even worse than PRCA!

J0hn_J0hn08

iTrader: (2)

Looking at the setup i see two "egr looking like" valves on the left and right side of the engine. Then i see a black box looking thing on the left side, im assuming thats the air pump? The air pump works off the pulley system? i was reading tech articles the other day on removing the smog equipment, the diverter valve is part of the smog equipment correct?

Im not sure if its related but from what i was reading id have to remove a pulley and get a bigger belt?

Honestly i would like to just remove the damn thing but id rather block it off until i can get my hands on a new valve. It really sucks when your car dies infront of people.. and everyone just stares at you while you rev to keep it on lol.

As a temp solution id like to just block it off, can anyone give me a Noobish step by step on how to tackle this? and the materials needed?

Heres pictures of what im looking at

Confuzed1

iTrader: (4)

I ran my L69 without a diverter valve for about four years. I can't understand the above post by Sparkytfl - I had no issues whatsoever with it not going into closed loop, since the O2 sensor on mine was way upstream of the CAT, and the engine ran just fine on cold or warm startups.

I got rid of the air diverter valve all together, and hosed the output from air pump straight to the CAT. I got absolutely no codes from the computer either. I just capped off the air manifolds. I passed two emissions tests in a row too with it that way, but there was no underhood inspection at the time in my state.

Sure, you can just "block it off" from the manifold, but since the port isn't open to the CAT either through that diverter valve, wouldn't you be dead ending the air pump? You'll either blow off the hoses or ruin your air pump I think...those cheap plastic diveter valves were junk from the day the cars rolled off the assembly line anyway, and they were only intended to shift the air to the manifold for what - the first ten minutes of engine operation to reduce emissions? Then it ends up pumping to the CAT anyways for the rest of the time.

Sparkytfl

The valve that controlled whether the air went to the cat or to the exhaust manifolds froze in the "to the exhaust manifolds" position on mine. Air was always dumped into the exhaust before my oxygen sensor. Computer thought it was running super lean and set the carb at full rich.

Glad I dont live in new york city. They do the dyno sniffer test too and it costs like $50. Upstate they just look and see if all the parts are there on a pre obd2 car, and stop doing that once its older than 25 years.

Confuzed1

iTrader: (4)

Ahhh...that would make sense then. It'll make the O2 sensor think it's running a little leaner than what it actually is. Thankfully, here in WI, they quit all emissions tests on pre-96 cars (OBD1). Back when they did test, it was free...they made up for it when you went to register afterwards though...

J0hn_J0hn08

iTrader: (2)

Is there a tech article on removing/blocking the diverter valve? Ive been searching and searching but i cant seem to find anything on it.

Sparkytfl

Theres probably not going to be an article, its so easy to do. Dont know what year your car is or what your specific valve looks like other than those too-close pictures, so I'm going off my 85. Its probably the same.

Find the two big rubber hoses that run between the diverter and the two exhaust manifolds. Remove those. They might have those stupid kind of clamps that you need to pry off rather than the normal kind with the worm screw, but its not hard.

Now there are one-way exhaust valves on the exhaust manifolds where you removed the hoses. Look like this. http://www.pciinc.com/index.php/gm/e.../check/valves/ Its possible that they dont work good-as-new and that some exhaust will leak through them now. If so, just put some rubber caps on them and clamp them in place to stop that. You can wait until the end to do this.

Find the big rubber hose that goes between the air pump and the diverter. Disconnect that at the diverter end. Find the big rubber hose that goes between the cat and the diverter. Its connected to the metal tube coming up from behind the engine by the heater box. Disconnect that at the diverter end. These last two hoses, these are the ones you're going to want to connect together (once the valve is removed and out of the way so just remember this and get back to this step later). Use a heater hose elbow and two clamps.

Disconnect the wires that go to the valve.

Find the thin rubber vacuum hose running to the diverter. Unhook that from the diverter and plug it. Either stick something in it to plug it or disconnect it at the other end and cap where it was connected.

The only other things connected to the diverter now should be the brackets holding it in place, plus another thick rubber hose connecting to a filter thing that you'll be removing too. So remove the valve now. With it out of the way you can join together those hoses I mentioned earlier.

J0hn_J0hn08

iTrader: (2)

Thanks for your help sparky

So far im doing good ive removed all of the following components below. However im having trouble understanding which hoses to connect if you could help me out a bit more id appreciate it.

Here are the pics of what ive done so far..


Overall View





Removed all of the following



I have this tube coming up and im not sure whether to remove this too? seems like its connected to the pulleys or something not really sure tbh.



I have a hose coming from behind the air cleaner that im not sure where to connect it looks like this



and is connected to this

Sparkytfl

Thats definitely a later car than mine. All the same parts are there, but they look different. Chances are that hose coming up from the pulley area is the one from the pump. Easiest way to be sure would be start up the car and feel if air comes out. If so, thats one of the hoses you keep, and connect it to the the catalytic converter tube once we figure out which one that is.

I really cant tell what that other hose is, the pictures are both too dark and too close. I see it has one of those one way valves to keep exhaust from getting into the diverter. Problem is both the exhaust manifold hoses and the cat hose all have one, so its not an easy indicator. If it connects to one of these http://cgi.ebay.com/ebaymotors/85-92...Q5fAccessories then its not what you want. If it connects to a metal tube going down behind the engine and connecting to the catalytic converter, then that would be what you connect to the one by the pulleys.

george 88gta

iTrader: (1)

If you are going that far in to removing the smog gear, why not just remove the air pump as well? I live in Dutchess county and have my GTA inspected annually by the GM dealer. He told me that all I need to stay legal is the catalytic converter and no codes. You can remove the A.I.R. pipes from the exhaust manifolds, plug the holes with 1/4" pipe thread plugs ( brass or stainless steel) and have a cleaner engine compartment and maybe pick up a few HP. Search the tech articles and look at the process for removing the air pump.

J0hn_J0hn08

iTrader: (2)

Well im a bit lost when it comes to the hoses i will probably try to video what i have done so far.. Im running the car like this, what problems am i going to have without connecting those two hoses?

The thing that confuses me is that the tube that goes to the cat connects from the cat to a one way exhaust valve.. The "hose" which is connected to the pulley does indeed blow off air but its not a hose, its metal.

Does anyone have a picture of their setup similar to mine so i can view the hose routes?

To remove the air pump id have to remove a pulley and get a bigger belt with a different set up correct?

As far as i can tell i have 3 one way exhaust valves is that normal?

Camarillo

I had all kinds of issues when my diverter was bad, 40 at the junk yard and i was back on the road. spray out the vent coming off diverter with carb spray to break up old deposits

Sparkytfl

Yes. One for each exhaust manifold, and the one for the cat. Sounds like yes you did determine which one was the cat as well as where the air comes from the pump (middle of this picture? http://i51.tinypic.com/29qbp4x.jpg ). Now you're just going to have to do some problem solving to figure out how to connect them together. Is there a rubber hose further down connecting that metal piece to the pump? Get a light and follow it down right to where it meets the pump. See if you can figure something out. On mine (85 v belt setup) it just looked like this http://s278.photobucket.com/albums/k...0.jpg&newest=1 with the diverter removed so it was easy to join them up. Sounds like the serpentine belt cars its not so easy.

J0hn_J0hn08

iTrader: (2)

So i should follow the tube thats coming from the cat to that one exhaust valve, put a hose on the valve and figure out a way to connect that hose to the metal tubing (throwing out air) coming from the air pump? What about the other 2 valves?

Will i run into problems if i run the car like this until this weekend? im planning on just getting rid of all the air tubes all together and the pump

george 88gta

iTrader: (1)

Yes, that will work, you will be sending the output from the pump directly to the cat. Ignore the other two valves. They are one way and if they are working, they will not let the exhaust gasses escape out in to the engine compt. Eliminating the AIR pump is relatively easy, but I would suggest that you find a friendly parts dealer who will let you purchase/borrow a few belts so you can correctly define the belt you need and return the rest. I found out that I actually needed a shorter belt. But thats just the way my luck usually runs.

jreyes916

http://i56.tinypic.com/2qsm4hs.jpg so this piece i also have but it broke off by the cat and its odd because where it broke off its facing opposite of the cat and people are saying it connect to the cat and i cant figure out where it goes or broke off so can any one help

george 88gta

iTrader: (1)

There should be an elboww elded to the drivers side of the cat. That is where the air line attaches to the cat. If it is broken at the cat and there isnt enough tube left to cap, you wil most likely have to replace the cat.

zachbulthuis89

Hey guys, so on my 89 camaro tbi, I took off the stock manifolds and air lines and installed shorty headers, Also took off the plastic housing AIR housing where the air lines and sensor off the cat hooked up to.. I'm left with the same elbow with the bracket end coming off the (smog?) Pulley which is where theair housing was connected. And also the air select and air delete wires. What do i need to do with these wires? Not sure if i should leave them open ended like they are, tape them together so theyre looped, or take them off where they connect somewhere else..Also I ordered a smog delete pulley so I guess that other pipe will come off with the smog pump.

irocrocks1234

Do you have a pic of said valve?

Tuned Performance

iTrader: (92)

Post #16 has a picture of the diverter valve.