Header Problem

smoker · Post by **smoker** » Sat Nov 03, 2007 5:11 pm

aaron_sk wrote:
Not only would that not solve the exhaust problem, but you'd still have to tune it and you'd be tuning it blind since you have no feedback from an O2 sensor.
BTW, Al, is it running unusually rich? Any time the ECM gets a low or nonexistant signal from the O2 it goes to full rich, which can cause the exhaust to snap. I've had problems with that before.

first of all this isnt an exhaust problem, it sounds like part of the fuel delivery system. which in this case may include the 02 sensorand you wouldnt be tuning it blind. by bypassing all the computer shit you would be right back to having a carb'd v8....imagine, tuning a car with a timing light and degree wheel or by ear and seat of the pants driving.....plus this being a tbi motor, the new carb and ignition system would allow for far greater performance mods to be done.

aaron_sk · Post by **aaron_sk** » Sat Nov 03, 2007 6:34 pm

I agree, the rich issue is probably causing the noise. I can artificially create the problem right now by screwing the AFPR all the way in and punching the throttle on my TPI Camaro.

However I fail to see how swapping to a carb makes anything easier. If I needed to tune the A/F ratio I would have to purchase an O2 sensor, take readings, and adjust from there. You would also posibly have to rejet if you're dumping to much gas. With TBI you can make all your adjustements with a laptop, and be done with it.

As for performance mods, there is nothing that can be done with a carb that cannot be done easier but costlier with EFI.

Purple RS · Post by **Purple RS** » Sat Nov 03, 2007 7:21 pm

I don't think this is a fuel delivery problem. The car ran just fine in bone stock form prior to putting the headers on. I believe I have all my leaks sealed up, and I have continuity from the O2 sensor to the ECM. The O2 sensor now instead of being about 3 or four inches from the head, now sits about a foot downstream and in a larger diameter tube, maybe that has something to do with it. Maybe I'll opt for a heated O2 sensor and see if that helps any.

aaron_sk · Post by **aaron_sk** » Sat Nov 03, 2007 7:27 pm

Can you tap one of the headers for an O2 bung Al? Mine is right above the drivers side flange, and it works pretty well.

smoker · Post by **smoker** » Sat Nov 03, 2007 7:39 pm

aaron_sk wrote:I agree, the rich issue is probably causing the noise. I can artificially create the problem right now by screwing the AFPR all the way in and punching the throttle on my TPI Camaro.
However I fail to see how swapping to a carb makes anything easier. If I needed to tune the A/F ratio I would have to purchase an O2 sensor, take readings, and adjust from there. You would also posibly have to rejet if you're dumping to much gas. With TBI you can make all your adjustements with a laptop, and be done with it.
As for performance mods, there is nothing that can be done with a carb that cannot be done easier but costlier with EFI.

well were gonna have to agree to disagree here then. efi can be modified to work as well as carb'd engines but not the tbi system, you can get far more power with a carb than with the tbi setup. the biggest problem people have with carbs is they think their stock small block needs a 750 double pumper just because they switched manifolds when a 600 is probably the best option for most streetable small blocks. i personally hate efi of any kind, i hate power adders too for that matter, do it on motor and motor alone or put on a skirt and admit you cant build a motor.

oh and the o2 sensor affects the fuel delivery purplers, thats what i meant

aaron_sk · Post by **aaron_sk** » Sat Nov 03, 2007 7:49 pm

I can appreciate the old-school idea of a huge engine and a huge carb, but those days are long gone. I personally don't want to own a car I cant drive on a regular basis, or one that can't start below 45 degrees, or one with such a choppy cam you can't idle.

BTW, stock TBI is crap, but I've seen guys getting good results with the Holley Commander 950TBI, or bottling it.

Purple RS · Post by **Purple RS** » Sat Nov 03, 2007 7:59 pm

aaron_sk wrote:Can you tap one of the headers for an O2 bung Al? Mine is right above the drivers side flange, and it works pretty well.

Which flange? Just after the head, or just before the Y-pipe? If by the head, which tube do you have it in? I'm not crazy about removing it from the car, although it's easier than the passenger side.

smoker wrote:oh and the o2 sensor affects the fuel delivery purplers, thats what i meant

Thanks, I realized thats what you meant after I posted

aaron_sk · Post by **aaron_sk** » Sat Nov 03, 2007 8:07 pm

Mine is just before the Y-pipe flange, yeah. If you don't mind throwing money at it, you can buy a new non-heated O2 for $25 at Schucks, or a heated one from TPIParts for $75.

Purple RS · Post by **Purple RS** » Sat Nov 03, 2007 8:11 pm

That's where mine is too, and the non-heated ones don't seem to be doing anything for me.

cargodz · Post by **cargodz** » Sun Nov 04, 2007 4:48 am

aaron_sk wrote:I can appreciate the old-school idea of a huge engine and a huge carb, but those days are long gone. I personally don't want to own a car I cant drive on a regular basis, or one that can't start below 45 degrees, or one with such a choppy cam you can't idle.

Now that's funny

I guess as the ultimate old schooler here I gotta jump in on this one since I was building up carburated cars/ trucks before most of you were out of diapers and some even born

LOL
So what you think we didn't drive anywhere during winter back in the old'n days when it got really cold... Heck my 78 Blazer I had (last carburated owned vehicle) was the only one that would start one year when it dropped to 30 below 0 with wind chills of -50-60... Don't get me wrong... there is pros and cons to both, but ya gotta love a vehicle that has a motor anybody can tear down and rebuild in a weekend.

Oh by the way... one more thing that may lead to your problem that I recently thought of... (and yes it has to do with the O2 sensor too)... If your new headers are thicker and larger diameter then you may not have the proper depth for the O2 to get a proper reading... I thought of this cause we encountered this problem on a truck a couple years ago... guess that's one of the downfalls of getting older, it takes me longer to remember stuff

LOL