inittab

So I took the camaro thats been sitting in my garage for 2 years to echeck today. It failed. but not by much.


I have not done any normal maintenance on the car yet and I'm about to do that now. (Dist Cap/Rotor, Plugs, Wires, Oil Change, Coolant Change)

Is there anything else anybody can suggest to do to get the NOx levels down?
I've done some reading and it seems it could be a problem with the EGR. This is a 350 TBI. anybody know the location of the EGR off hand or if it has one? Any help is appreciated. Thanks.

sloick

ohio hasnt done echeck in years. what changed?

inittab

well ohio is one of those weird places see.... they think running echeck in only a few counties is going to make a difference. so we have a bunch of testing stations around summit, cuyahoga county that have like 6 echeck lanes right, well they normally only have one lane open whenever I go there. they recently took away the $20 toll to get your car echecked. And echeck in these counties have done nothing for pollution control but they are too high and mighty to just get rid of the program

figured this might help diagnose the problem but I also have a bouncy idle and sometimes the car really bogs down at take off, then catches itself and bolts. Any idea what might be causing this?

RBob

iTrader: (1)

With the HC also right at the limit along with the driveability issues, I'd first check the fuel pressure. A lean AFR will cause both high HC and NO, and make the engine stumble and hesitate.

If the engine ran well, then I would look at excess spark timing. That too will cause high HC & NO, but the engine would run better.

A simple EGR system test is also recommended. At idle push up on the EGR valve diaphragm, the engine should instantly stall. If it doesn't then the EGR passages are clogged.

RBob.

inittab

Alright thanks, I will try to that tomorrow, running out of fuel screwing with it and I spent all my money on tune up stuff that didnt make a difference =P. I did find the EGR and clean it out with some pb blaster and carb cleaner and it seemed to make a little difference. I will try to move the diaphram myself and see if I can get it to stall. i will also check into how much a fuel pressure gauge is and see if I can afford it right now. Is there a shrader valve somewhere on the TBI system where i check it? I haven't really followed fuel lines yet.

RBob

iTrader: (1)

Unfortunately there isn't a fuel pressure test port. Not sure why GM didn't put one in either. The easiest place to install a tap is on the flex line between the frame and TBI feed. This would be the larger of the two lines.

RBob.

inittab

Hrm. Figures. What do you mean by tap?

RBob

iTrader: (1)

A place to measure the fuel pressure. The fittings are 16mm Saginaw style (w/o-ring). There are fittings available that fit in that location along with being able to get gauges that also have a fitting.

RBob.

inittab

Finally got a chance to pull the codes.

Showing codes 23 and 44

23 Inlet air temperature sensor signal showed an air temperature below -22� F after the engine has been running for 5 minutes.

44 Oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation.

Any ideas what might be happening here and if thats related to my bogging/crappy idle issue?

One other thing, those of you with a 350 TBI what car do you say you have to get the correct parts for the motor? I'm not sure what this came out of tbh.

RBob

iTrader: (1)

Code 23 for the IAT can be from running the engine with the sensor unplugged. Of course the sensor may also be bad.

Code 44 for O2 lean could be from low fuel pressure.

As for parts, the only items that differ are the inejctors, ESC filter and knock sensor. The injectors should be changed to 5.7l injectors (if they already haven't been). The ESC file & sensor I wouldn't worry about unless there is an issue.

RBob.

inittab

I checked the #'s on the fuel injectors and they are both labeled 5234105. I can't find much on that number besides that it's a fuel injector. do you know if these are the ones it should be running?

TechSmurf

http://www.carburetion.com/pdfs/injectors_tbi.pdf

If this is correct.. and it probably is given the level of detail.. I'd say those came off a 4.3 V6.

My knowledge says the 4.3l injector flows 40lbs/hr, vs the LO3 injectors flowing 45lbs/hr, vs the LO5 injectors flowing 55lbs/hr.... I feel bad for your engine.. get new injectors, then go find the previous owner and

inittab

Well thanks to all those that helped the beast has passed with flying colors. After getting those v6 injectors out of there and putting i the proper 5.7l injectors the car now idles correctly, doesn't bog down, and it feels like its ***** have dropped. it's like driving a completely different car now.

thanks again

TechSmurf

Yanno what really confuses me is that you added 15lb/hr of fuel (edit: per injector) and reduced your hc emissions..... the heck?

RBob

iTrader: (1)

With the proper AFR there is a more complete cleaner burn. Note how much the CO dropped with the 350 injectors. High CO is a sign of an incomplete, inefficient burn.

The high NOX is also a sign of a lean AFR. This is the prime reason that the EPA won't allow lean cruise highway modes. That is until NOX reduction cat's are good enough to lower it within limits.

RBob.