Hi everyone,

I took my '92 Trans Am convertible out for a drive last week and noticed it was idling rough at stops and on the way home from about a 20 mile round trip the SES light came on. I put my red brick Snap-On scanner on it and it gave me a Code 45 RICH EXH. During the week, I cleared the code, took off the intake duct hose and sprayed carefully around the butterflies with some carb cleaner, and changed the o2 sensor which was very black and sooted. It idled fine on start up in closed loop, so I take off for another drive. Sure enough about 5 miles into the drive, the SES goes off again and again its Code 45.

Any suggestions, or if someone could help me decipher what my scanner is telling me, I could post up what it gave me when I returned from the drive as I am still trying to learn OBD I

BTW the car is a stock 305 auto and has 70k miles. The plugs, wires and distributor cap were replaced at 55k, but that was in 2001.

Thanks in advance,

Jason

 

If you have your sevice manual handy giv it a look. There is a flow chart in there 4 code 45 and what to look for to fix it. I'm away from the garage our Id look it up 4 ya.
If your INJs are stock I would start there. OHM them and also check your fuel PSI reg vac hose for raw fuel.

 

Thanks Tony, Ill check that out in my manual as well as those other things. Hope the married life is good!!

 

Thanx! Nuthn like it !!!

 

UPDATE! I removed the charcoal canister to see if there were any obstructions in the canister or lines and the charcoal canister was completely full of fuel!! Any ideas what might have caused this and how to correct it? I checked my service manual and did a search on TGO and didn't see anything specifically pertaining to this to help.

Thanks,

Jason

 

Check the fuel presure regulator. Thats the only thing I can think of

 

I agree to start with the FPR vac line. The canister full of fuel would have been further down my list. Did someone squeeze the tank full on a fill up? That can cause it. There is a fuel air separator in the tank, where the purge vapor hose attaches. That may have come apart. There is also a fuel tank pressure control valve, basically an over pressure vent, on the frame rail just where the rubber fuel line sections connect to the hard lines. That may be plugged.

 

Over filling the fuel tank will do this. First thing I was taught 10 years ago on these cars was that once the pump clicks off, or you hear fuel coming up the filler neck, stop filling. It used to be fairly common.

 

Thanks everyone for the input. I will start checking off the items listed tomorrow and report back in a few days.


Jason

 

I have checked and found a couple of things that I thought could have contributed to the code 45 over the last week. I am not gong to let this thing whip me. First, I found and repaired a hole in the vacuum line that runs from the charcoal canister to the plenum where it was rubbing against the A/C bracket. Then I checked the TPS and found that it was only showing 3.70v at WOT, so I replaced it.

I checked the fuel pressure control valve and it is working correctly, as is the vent at the fuel tank over the axle housing. The FPR vac lines are all connected and appear to be in excellent shape. I guess ohming the injectors themselves is next. I was trying other avenues before removing the runners to replace the FPR and I'm really hoping its not the fuel air separator in the tank.

Am I still headed in the right direction guys? Any other suggestions? Thanks for all your help!

Jason

 

I think I have finally found the problem. I ohmed the injectors, which I probably should have done first, and one of them is reading at 5.4, one at 15.5 and the other six at 16.5. So I guess it is time for a plenum pull. Now the next question, should I just change the one bad injector or change them all even though the others are strong? Is there anything else I should replace under the plenum while it is off for preventative maintenance?

Jason