Run rich from factory???

[Camvill]

My friend tells me that 94 camaros run alittle rich from the factory so he telle me if i get a adjustable fuel pressure regulator and get a new ignition and turn the fule pump down alittle it will burn better and create less emissions, which i need to pass inspection lol. What u guys know about this

[GP99GT]

no.

[Fast92RS]

um theres something else wrong.

[Pampered-Z]

Yes, the ODBI LT1s do run on the rich side in the upper RPMS, but you would need to reprogram to resolve the problem. Changing FP will have no effect as the ECM will just compensate by adding injector pulse to richen it back up.

Weak O2 sensors can also cause the car to run a bit richer and the OBDI ECM is more tolerant of this before it will throw a code. You would need to scan the car and look at the LBs,IPs and O2s to see if the ECM is compensating. Also make sure the EGR is functioning properly. Over time carbon builds up in the intake track and could result in the vavle not closing completely or the port being blocked.

Upgraded ignition does have allot of good benefits; the early LT1s do have weaker coils then the later 95 models. I run the Eccel 300+ igin. It has a hotter then stock coil and also "double sparks" at lower RPMs (this is switches to single spark around 4,000RPMS). Which is said to help ignite any unburned fuel and help with bottom end power and lower emissions.

JB

[BonzoHansen]

Jon, IIRC, he failed inspection for high NOX. I thought he said he had a new EGR valve, but I wondered if it might have a bad EGR solenoid or other related part, or a coked up intake. I don’t know these setups at all or common failure points, so I'm going by what I've seen in the earlier ones. Thoughts?

[Pampered-Z]

Originally Posted by BonzoHansen

Jon, IIRC, he failed inspection for high NOX. I thought he said he had a new EGR valve, but I wondered if it might have a bad EGR solenoid or other related part, or a coked up intake. I don’t know these setups at all or common failure points, so I'm going by what I've seen in the earlier ones. Thoughts?

OK, didn't realize he was actually failing that badly.

Normally the EGRs go bad they stick open a bit, which noramlly doesn't throw a code. But more often they aren't closing because of build up then from having gone bad. You can sometimes feel the car "stumbel" at cruising speeds 35-45 MPH, or if you lightly power brake the car, and it stumbles the EGR is not closing all the way.

So having a clogged ERG track is actually more common then a bad EGR, it's a common failure point for emmisions. Because the LT1s pulled right from the exhaust header, as the engine gets older it builds up crap in the intake, plus if it starts to burn a little oil it gets pulled into the intake and baked into the manifold.

Dealer wanted some outragious price to remove and clean the intake. We've been able to fix it many times with a treatment of Seafoam, then replacing the plugs and O2s. instead of pulling the intake.