Hello gang. My mother has a 1988 model Olds Delta 88 with over 150,000
miles that is having a problem passing the emissions test for its yearly
state inspection. The car has the VIN#C 3800 engine. The test results were:
(1) HC(PPM) Standard-152, (Current Reading-359 Fail High and Low RPM)
(2) CO% Standard-0.97, (Current Reading-9.87 Fail High and Low RPM)
(3) CO2% (Current Reading-8.3)
(4) NOx Passed Well at 80 PPM
(5) O2% is 0.4
(6) Dilution% Standard-Less Than 6, (Current Reading-18.2)
(7) Gas Cap Integrity Passed
After it failed she brought the car to me and I pulled the dipstick and
smelled strong gas in the oil and the computer had a hard code 41 (cam
sensor). I checked the following concerning the gas in the oil and code 41:
Fuel Pressure and Flow
Fuel Pressure Regulator Diaphram For Leaks
Vapor Canister (Couldn't Tell Much Though)
Injector Leak Down Test
Cleaned Throttle Body and Tested the IAC
Checked the Type 1 DIS ( All Six Firing Blue)
Changed Oil and Filter Twice
Changed Cam Sensor and Felt Magnet On Pole (SES went out for a few hours
then came back on)
Added Fuel Injector Cleaner and Drove A Few Days With 93 Octane Gas
Other things replaced in the past 6 months:
Plugs, Plug Wires, Coil Pack, Fuel Filter.
The second test result which I just saw didn't change. The tech said she
might try replacing the O2 Sensor which I just did (After the second test).
The tip of the O2 Sensor was very black with HC contamination. The SES
light was on again, (hard code 41) during the test.
Concerning the Code 41 (Cam Sensor), I have replaced the Cam Sensor three
times in the last 6 to 8 months. The SES light will stay out for a week or
so and come right back on and stay on until I replace the sensor again, then
it will do the same thing, last a week or so, and go bad again.
There seems to be a slight tip-in hesitation and my mother said it stalled
backing out one time.
I have come up with this possible cause:
I think the timing chain is loose causing the high HC and CO readings and
the code 41 is caused by the magnet being out of adjustment due to the loose
chain changing the valve timing and/or the magnet although it is in place,
may also be to weak to fire the cam sensor due to age.
I think I should replace the tensioner, chain, gears, magnet, and crank
sensor as well because it works with the cam sensor too.
What do you guys think? Has anyone had a problem like this where the cam
sensor will work for a while then quit?
I'm sorry for the long post and I appreciate the help. The man said he'd
test it one more time for free. This is making me
pull my hair out. My MT2599 Snap-On scanner was stolen so I dont have real
time Block Learn or Intergrator info. I had to use the paper clip trick to
get the codes.