Engine missing really bad.... sometimes?

danman · 05-21-2006, 06:51 AM

I just bought this car a couple of weeks ago and it started missing on my 5 hour drive home from buying it. But then the next day it was fine. The car seems to be running really rich. There is a lot of black dust on the rear bumper cover and it pops when I shift. I started with a tuneup. New plugs and wires, O2 sims, changed the oil, and cleaned the MAF and air filter. It ran fine for a day or so and then it started missing again. It sounds like it has a cam now. Where do I start?
It threw a SES code one day last week, but it went off before I could check it.

**sunsetorangess** · 05-21-2006, 12:10 PM

You said you changed the 02 sims but what about the 02 sensors?
if its got lt its gonna run a lil rich. How many miles are on the car? Did all of the plugs look the same when pulled? any just smell of real bad fuel or anything?
Hows the oil look? How did you clean the maf and filter?
J

**2001NBMZ28** · 05-21-2006, 01:46 PM

Get the code read, it'll still be in history even with the light off - most stay there for 40 ignition cycles.

danman · 05-21-2006, 05:20 PM

I put O2 sims on it to eliminate the O2 sensors.
The car has 87,000 miles on it. I sprayed the MAF with electrical contact cleaner and the air filter is a Holley reusable filter.

I tried to put a Scanmaster on it and the scanmaster wouldn't power up. Something seems to be wrong with the PCM port under the dash. The guy I purchased the car from said that he ran Autotap on it a week before I bought it and it worked just fine. I am getting really frustrated with this car.

**2001NBMZ28** · 05-21-2006, 05:37 PM

02 sims are just for the rear 02's, shouldn't affect performance (unless connected to the front by mistake). If you don't have power to the DLC under the dash check your CIG/ACCY fuse.

**sunsetorangess** · 05-21-2006, 05:52 PM

I just assumed you put the sims in the rear, and you have the front two hooked up too the harness. If ya got a chinazone or advance auto around you they will hook up there kool scanner and see if it works. Like above check your fuses.

**SR71** · 05-22-2006, 03:24 AM

Have you checked you pcv? If you have almost 90k on the clock, it maybe time to change that. They'll make your idle act really funky if they get clogged. Should be on the passenger side along the intake manifold if you have a 98 and 99? If you have a 00 - 02, it'll be a little easier to get to, same line, same side, but going into the bottom of the throttle body. Plus, they're only like two dollars or so. Good luck.

danman · 05-22-2006, 04:17 PM

Well, I checked the PCV valve and I just barely touched it and it fell out of the tube going to the intake. It was pretty gunked up. I put a new one on it. We will see if that helps. Like I said before, it only does it every once in a while. It was fine on my way to work this morning.

I will also try some fuel injector cleaner.