Jtd988

So I just bought this 1988 Camaro with a 2. 8 V6. I had a 89 is my first car when I was in high school so bought this one to bring it as close to the one I had as I can and use it as a daily. The car runs phenomenal, and since I bought it I've replaced every sensor on it, including the 02, with the exception of the mass airflow which I tried, but the new one from autozone was bad, go figure... and have also done new dynomax exhaust, which is what I had in high school, and a new cat. The only code I have is a rich code. I've replaced the air filters, and plugs as well. The car still has EGR, and a smog pump, though the previous owner disconnected the smog line from the pump to the cat... So it's free blowing.. and the new cat that was put on has no place for a line. It also has a hypertech thermomaster chip. As I said, the car runs perfect, but I have just found a couple bad vacuum lines that I'm fixing as we speak, and since I had the intake off to get to them, going to go ahead and do a new fuel regulator for the hell of it, and also threw on a new egr. I'm just confused on how this could throw a rich code, which only happens once it hits about 190 degrees after a little bit of driving, and is intermittent, and comes and goes, but yet the spark plugs are burning perfectly, with zero signs of richness, but also it is getting horrible gas milage, like maybe 10 a gallon, and spitting fuel out the pipes.. which.. honestly could be condensation, but with the milage and the code.. was leaning toward unspent fuel.. any ideas? I just received a used oem computer and prom in the mail I'm gonna try as well to see what happens.. but regardless... How could fuel make it past the plugs, without burning rich.. but yet throw a rich code at the O2 and come out the exhaust?. Plugs should be showing something rich... Any help is much appreciated. Oh yeah, also, the oil level is perfect.. no extra fuel in the oil.

PaulyC

The fact you're mpg is so bad means that code is probably right. Assuming this is a code 45 a few things to look at are actual fuel pressure, did this start right after you replaced the regulator? You should see low to mid 30s idle and mid 40s at high load (low vac). Check the injectors for leaking and possibly a balance test. You also mentioned you were going to replace the MAF, was there an issue or was it just a maintenance swap? Check TPS voltages (although I think you would get a separate code along with that one) and finally EGRs stuck open can cause this.

Jtd988

The mass air flow was just a maintenance swap, as were everything else when I bought the car. Instead of guessing what the owner may or may have not done to it to keep it up I went ahead and started throwing a few dollars at it. The tps is new, and I got it set to the correct voltage. Haven't done the regulator yet, should be done by today and the EGR I did last night but haven't got it all back together yet to start the car, and as I was saying I found a few small vacuum leaks along the way I've corrected since it's been apart as well. I was wondering the same thing about maybe injectors, just confused on how the plugs could be perfect. I'll probably still throw another maf at it if I can find a good one somewhere. Ive heard nothing but bad about most of them out there for sale, so I guess it's kind of hit and miss. I'll look Into the injectors and regulator psi and see what I can find. Thankyou again for the help, I really appreciate it.

zs&tas

still got that hyper chip ? Get rid of it.
check temp sensors, maybe staying in open loop
Check for leaky injectors, fuel pressure, and have you checked your timing ?

zs&tas

Sorry ! Also , that bad mileage you could be losing vapours somewhere , you say it's running well , I wouldn't think it's that rich. Maybe check tank vent and charcoal canister ?

Jtd988

I really appreciate the input guys. I just got it all back together, fixed three vacuum leaks, one at the pcv line that runs into the intake hose right before the throttle body, one damaged, and dry rotten line at the smog pump, and one broke line at the fuel regulator..put a hotter coil on, changed the EGR valve with a new one,and put a new fuel regulator on, in which the old one was all sorts of caked up inside.. I also looped the coolant line from the lower intake that runs through the plenum back to itself.. don't need that craziness in this 200 degree Texas heat... Car runs cooler for sure, drove all over and could not get the light to come on so far. Usually it had come on with 15-20 mins. Definitely runs even smoother,so crossing my fingers that between the vacuum errors and crappy regulator and old EGR..I might have fixed the problem.. I'll post again if something pops back up.thankyou again for your advice and input. Theres definitely alot of good info and people on this site. I also haven't changed the prom yet back to stock. Waiting to see if I can get the light to come back on, and then change it to see if that could be the problem if it happens. Also I believe I was mistaken and it was actually condensation out the exhaust