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TBI/ECM problems without air pump?

BadDog

BadDog

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Ok, looks like I'll be going to rams horns to do the exhaust the way I want. But, I'm wondering what lack of the air injection system will do to the ECM?

Whay about my emissions? When (if?) I get around to tagging this thing, it will be a "special construction" title where I only have to meet emissions "sniff" at the pipe so the hardware is not an issue. Don't have a cat anyway...
 
I haven't had any problems with my disconnected air pump, I believe it only pumps air into the exhaust. Of course I have to deal with visual inspection and will have to replace it next year for smog purposes.
 
Get a custom burnt chip. Give the techs all the info about your engine. It will run better.
Tell them about;
your cam
vaccum
compression ratio
cubic inches
exhaust (type)
have the model of your computer
type of heads
I think they even wanted gear ratio?!
My 468 ran like crap until I got the right chip.
Now it's like I have the benfits of a double pumper.
Just my .02
Gorrilla
/forums/images/graemlins/thumb.gif
 
Thanks guys, gotta love the quick responses on this board. /forums/images/graemlins/laugh.gif

I thought about a "chip", but all my stuff is pretty much common, stock, off the shelf, parts and I really want to keep it that way unless I find a good reason to deviate. I like knowing that I can just walk into any Autozone and be pretty much guaranteed they have what I need on the shelf. Not that I like shopping at AZ, but "on the road" and late at night on Saturday, it's nice to have the option instead of "wait till Monday when Big Bob's High Po Shop in 'the big city" 30 miles away opens on Monday"...

Anyway, I don't think this will screw with the computer, but I didn't know what affect it might have on the O2 sensor... Isn't it mostly to help the converter anyway?
 
i ran my '88 350 tbi without a belt on the air pump for a year with no problems. i had to replace it to get it smogged and tagged here in las vegas.

bubba,
i thought the air pump recycled exhaust gases into the engine to burn them again to help clean the exhaust. if someone knows the right answer for sure, could you please let us know.

rick
 
In most cases AIR is used to clean-up the exhaust emissions during the warm-up cycle. A time when the engine is run rich and the extra O2 helps the converter burn off the exsessive HC (fuel).

Allthough, thats not allways the case. For example, early Ford 460s ran dual Air pumps to delute the exhaust inorder to pass the standereds. (not positive about that tho')

At any rate,
I doubt removeing the AIR will send the ECM into a fit, since the engine should be in Open-Loop during the warm-up cycle anyways.
I'd have to look at the books to be sure, but thats how I remmeber it.
 
[ QUOTE ]
recycled exhaust gases

[/ QUOTE ]

Thats the EGR system. The EGR sys. recycles exhaust gasses back into the engine during the intake stroke. This cools the combustion temps and reduses NOX (actual smog) emissions.
 
NO, all the air pump does is pump air into the exhaust to clean up emessions. Look at where the little line enter the exhaust!
As for not having a cat, It provides some back pressure so the O2 sensor can get a good reading on the amount of O2 in the exhaust.
The O2 sensor, the temp sensor, the knock sensor, HAVING THE RIGHT THERMOSTAT!!!!, and the distributer spark sensor are what makes the fi work so good on fuel economy.
FI, to work to it's maximum capacity must have these sensors.
Forget about speed sensors and EGR switches.
If you have eliminated a electronic transmission, The comp will be looking constantly for these inputs and modify operation accordingly.
Take a nissan for example, if your plugs are worn, the comp will back off fuel delivery to maximize economy.
Fords will check each cylinder for compression and throw a code if the rpm drops if it shuts a cylinder down. They started that [naughty word] in the mid 80's.
If you modify a GM fi system, either thru elimination of a sensor or a component it will modify the way the engine operates.
Even tho a Gm computer is 'dumb', it still can fkup economy and performance.
Gorrilla
 
Gorilla, I'm not following you at all. I know the sensors are required for the factory chip (or any closed loop chip), and I have not eliminated them or compromised them. In fact, it's the effect that eliminating AIR might have on the O2 sensor that I'm concerned about. As for lack of back pressure, the 3" into 2.5" 34"(?) glass pack seems to provide ample b.p. to keep the comp happy. At least there is no problem I've seen in WinALDL series data...

Oh, almost forgot, the only sensor I’ve eliminated is the VSS but I don’t have a speedo so… Anyway, for a trail only rig, it seems to work just fine without it.
 
Sorry man, I am just talking about maximum performance.
I may have thought that you have bulit a engine for your trail rig, My bad.
no I am not trying to be a richard head but I have had some problems with what I have done and this is how I fixed it.
Gorrilla
 
I just looked at the book,(HeHeHe, still got it and no ones asked for it /forums/images/graemlins/wink.gif) I see no resson why it would kick a code w/o the AIR system. (I don't see any "feed-back" to the ECM. The ECM commands the AIR valve to the exhaust (on - during warm-up) or to the cleaner (off - normal temps) - thats it)
 
No sweat. Thanks for the suggestions anyway. But, my engine is stock. I don't need much power for a rock crawler; I'm much more interested in gears, suspension, and removing unneeded weight. I like stock for reliability and maintainability. The only time I deviate from common/stock is to simplify…
 
Sweet! Thanks for checking. YOU DA MAN! /forums/images/graemlins/thumb.gif
 
LOL! SWEET! Darth truggy strikes agian! /forums/images/graemlins/rotfl.gif
 
"Resistance is futile, you WILL be assimilated..."
 
Went to Independance, heard all the toyoyta and jeep talk I could Stand!!!!!!!!!!!!!!!!!!! /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif
Time for the FULLSIZE TO TAKE A STAND!!!!!!!!!!!!!!!!!!!!!!!1 /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif /forums/images/graemlins/truck.gif
Gorrilla
 
On the AIR issue, unplug whatever switches it, and see what happens.

You've got winALDL (sweet) so watch what happens when its not working. From what has been discussed here, and what my '86 preliminary truck manual shows, AIR is injected into the manifold under other than warmup conditions, which is exactly opposite the car system.

However, big difference there, '86 is CCC, vs. your TBI. All the '88 TPI stuff that I can find in both the electrical and service manual for the Camaro shows no reason AIR should trigger a code when disconnected, as AIR is just diverted (to converter when closed loop) and not "monitored". I would have to guess an '88 Camaro is more similar to a TBI truck than the CCC truck system is to a TBI truck system.
 
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