1) O-2 sensors (mileage)
2) Plugs (every 5000 mi)
3) Wires (every 9000-10000 mi w/ your mods)
4) That controller?
2) Plugs (every 5000 mi)
3) Wires (every 9000-10000 mi w/ your mods)
4) That controller?
Diagnosis ? Car runs rough/sputters abit at startup...
- Thread starter JonB
- Start date
SteveBCloud9
Enthusiast
O.k. JohnB, tell us again why we need to change plugs at 5000 miles.
Have you replaced the battery?
RockyTop
Enthusiast
and the air/fuel meter on my Roe calibrator seems to indicate its running richer more often as it nevers cyles down to the leanest setting as often as it used to. I also seem to be getting more black exhaust spit on the back of the car.
One of the car geeks who works here suggests it is either an O2 or mass airflow sensor going bad and causing the computer to enrichen the mixture. I have yet to pull the plugs, but in light of the rougher running at start up, I will not be surprised if it has some that are fouled.
Any thoughts ?
One of the car geeks who works here suggests it is either an O2 or mass airflow sensor going bad and causing the computer to enrichen the mixture. I have yet to pull the plugs, but in light of the rougher running at start up, I will not be surprised if it has some that are fouled.
Any thoughts ?
jamie furman
Enthusiast
Hell I thought that was normal.
Rocky,
If you're not getting a check engine light or code and it's only right after startup, it's most likely something mechanical that the PCM cannot detect, such as a spark plug, wire, etc. (not the controller as it is tied into the PCM, and you'd get a check engine light with a code 14).
My bet, since your car is 5 years old, if it's right after you first start it up, you've got an injector or more that's letting fuel pressure bleed down after shutdown (it's supposed to hold pressure for the next startup) and the fuel is fouling the plug(s) a bit at startup. Have your mechanic put a fuel pressure gauge on the manifold and see if the system holds it's pressure with the engine off. If it's bleedeing down slowly, you can probably cure it with an injector clean and flush (professional, not the stuff you pour in your gas tank).
Good luck.
If you're not getting a check engine light or code and it's only right after startup, it's most likely something mechanical that the PCM cannot detect, such as a spark plug, wire, etc. (not the controller as it is tied into the PCM, and you'd get a check engine light with a code 14).
My bet, since your car is 5 years old, if it's right after you first start it up, you've got an injector or more that's letting fuel pressure bleed down after shutdown (it's supposed to hold pressure for the next startup) and the fuel is fouling the plug(s) a bit at startup. Have your mechanic put a fuel pressure gauge on the manifold and see if the system holds it's pressure with the engine off. If it's bleedeing down slowly, you can probably cure it with an injector clean and flush (professional, not the stuff you pour in your gas tank).
Good luck.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by steveb:
O.k. JohnB, tell us again why we need to change plugs at 5000 miles. <HR></BLOCKQUOTE>
In normal driving, and OE Viper will benefit from smoother idle and crisper acceleration...noticably so, with just a $25 parts expense!
On modified cars, esp w/ hi-heat SVSi headers like the poster mentioned, and given his complaints, HE should consider an extreme-service 5000 mile plug life, and 10K-12K wire life.
O.k. JohnB, tell us again why we need to change plugs at 5000 miles. <HR></BLOCKQUOTE>
In normal driving, and OE Viper will benefit from smoother idle and crisper acceleration...noticably so, with just a $25 parts expense!
On modified cars, esp w/ hi-heat SVSi headers like the poster mentioned, and given his complaints, HE should consider an extreme-service 5000 mile plug life, and 10K-12K wire life.
